Composting as a solution to the increasing generation of municipal solid waste (MSW), also contribute to GHGs emission when not controlled and could lack some basic nutrients, especially nitrogen. This study assessed ...Composting as a solution to the increasing generation of municipal solid waste (MSW), also contribute to GHGs emission when not controlled and could lack some basic nutrients, especially nitrogen. This study assessed the split-additions of nitrogen-rich substrate to composting materials and their effect on GHGs emissions as well as the quality of the composts. Nitrogen-rich substrates formulated from pig and goat manure were co-composted with MSW for a 12-weeks period by split adding at mesophilic (˚C) and thermophilic (>50˚C) stages in five different treatments. Representative samples from the compost were taken from each treatment for physicochemical, heavy metals and bacteriological analysis. In-situ CH<sub>4</sub>, CO<sub>2</sub>, N<sub>2</sub>O gas emissions were also analyzed weekly during composting. It was observed that all the treatments showed significant organic matter decomposition, reaching thermophilic temperatures in the first week of composting. The absence affects the suitable agronomic properties. All nitrogen-rich substrate applied at thermophilic stage (Treatment two) recorded the highest N, P and K concentrations of 1.34%, 0.97% and 2.45%, respectively with highest nitrogen retention. In terms of GHG emissions, CO<sub>2</sub> was highest at the thermophilic stage when N-rich substrate was added in all treatment, while CH<sub>4</sub> was highest in the mesophilic stage with N-rich substrate addition. N<sub>2</sub>O showed no specific trend in the treatments. Split addition of the N-rich substrate for co-composting of MSW produced compost which is stable, has less nutrient loss and low GHG emissions. Split addition of a nitrogen-rich substrate could be an option for increasing the fertilizer value of MSW compost.展开更多
Mixed mesophilic and extreme thermophilic bioleaching were evaluated to remove copper from the molybdenite concentrate.Bioleaching tests were carried out in shake flasks and in a 50-L bioreactor.The shake flask tests ...Mixed mesophilic and extreme thermophilic bioleaching were evaluated to remove copper from the molybdenite concentrate.Bioleaching tests were carried out in shake flasks and in a 50-L bioreactor.The shake flask tests were performed with different inoculum size,solids density,pH.and temperature in order to identify optimum conditions.The highest amount of copper elimination,75%was obtained with extreme thermophilic microorganisms(at 12%inoculation,10%solids,65℃and a pH of 1.5).The highest copper elimination by mesophilic microorganisms was 55%(at 12%inoculation,5%solids,30℃at pH 2).The optimum conditions in shake flask tests were applied to 7 days batch tests in a50-L bioreactor.Extreme thermophilic experiment gave the best copper elimination of 60%(at 12%inoculation,10%solids,65℃and pH 1.5).Mesophilic test removed 50%of the copper(at 12%inoculation,10%solids,35℃at pH 2).展开更多
Creosote is used for preservation of railway ties and timbers, electric utility poles, marine and foundation piling, fences and garden furniture. Creosote-treated wood waste may cause potential contamination of soil a...Creosote is used for preservation of railway ties and timbers, electric utility poles, marine and foundation piling, fences and garden furniture. Creosote-treated wood waste may cause potential contamination of soil and water if they are not disposed properly. Creosote contains over 300 organic compounds including polycyclic aromatic hydrocarbons, phenolic compounds and heterocyclic organic compounds, many of which are toxic to human and can cause damage to kidney, liver, eyes and skin. The feasibility of using a composting technique inoculated with the cellulose degrading actinomycetesThermobifidafusca as a mesophilic/thermophilic bioremediation option to degrade phenolic compounds in creosote treated wood waste was evaluated. The temperature profile of bioremediation process clearly identified mesophilic and thermophilic phases in both experiments. Different degradation rates were observed in the mesophilic and thermophilic phases. Fluctuations of pH was observed in both experiment as the result of the breakdown of organic nitrogen to ammonium in the first week and the formation of organic acids and the loss of ammonium with the exhaust gases in the latter stage. The moisture content decreased in both trials because of the net loss of water with the exhaust gas. Both experiments achieved similar reductions in total carbon and TKN, volatile solids and phenolic compounds, cellulose and lignin indicating similar levels of microbial activities during the composting process. The stability and maturity of the final products were also similar. The inoculation of the cellulolytic-thermophilicactinomycetesThermobifidafusca did not manifest observable differences in degrading cellulose, lignin and phenolic compounds compared with the control.展开更多
Hydrogen production from palm oil mill effluent (POME) by Thermoanaerobacterium thermosaccharolyticum PSU-2 was investigated both in batch and continuous reactors using anaerobic sequencing batch reactor (ASBR) and co...Hydrogen production from palm oil mill effluent (POME) by Thermoanaerobacterium thermosaccharolyticum PSU-2 was investigated both in batch and continuous reactors using anaerobic sequencing batch reactor (ASBR) and continuous stirred tank reactor (CSTR). The hydrogen production determined from batch experiment of POME at an inoculum size of 0%, 10%, 20% and 30% (v/v) was 161, 201, 246 and 296 mL H2/g-COD with COD removal efficiency of 21%, 23%, 23% and 23%, respectively. Continuous hydrogen production was start-up with 30% (v/v) inoculum in both ASBR and CSTR reactors and more than 30% COD removal could be obtained at HRT of 4 days, corresponding to OLR of 11.3 g COD/ L·day. Similar hydrogen production rates of 2.05 and2.16 LH2/L. day were obtained from ASBR and CSTR, respectively. COD removal efficiency of ASBR was 37.7%, while it was 44.8% for CSTR. However, ASBR was stable in term of alkalinity, while the CSTR was stable in term of hydrogen production, soluble metabolites concentration and alkalinity. Therefore, the CSTR was found to be more stable in hydrogen production than ASBR under the same OLR.展开更多
The paper provides a critical comparison between mesophilic and thermophilic anaerobic treatment of PTA wastewater through diagnosis of a case study. Aspects covered are bioavailability, biodegradability, microbial po...The paper provides a critical comparison between mesophilic and thermophilic anaerobic treatment of PTA wastewater through diagnosis of a case study. Aspects covered are bioavailability, biodegradability, microbial population, thermodynamics, kinetics involved and bio-reactor design for PTA wastewater treatment. The results of the case study suggests that one- stage thermophilic anaerobic reactor coupled with coagulation-flocculation pre-treatment unit and an aerobic post treatment unit could be techno-economically viable for PTA wastewater treatment to ensure that the final effluent quality conforms to the international standard. The in-formation emanated from this study could be useful and thought provoking to the professionals and academia in the area of PTA wastewater treatment and can serve as impetus toward the development of research lines in similar problems like the treatment of other petrochemical wastewater such as phenol-con- taining wastewater, benzene/benzoic acid-con- taining wastewater or wastewater from other similar industrial settings.展开更多
The thermophilic filamentous fungus, Thermomyces lanuginosus produces the largest amount of xylanase reported. In addition to this, it expresses large amount of other enzymes that have been used industrially or have a...The thermophilic filamentous fungus, Thermomyces lanuginosus produces the largest amount of xylanase reported. In addition to this, it expresses large amount of other enzymes that have been used industrially or have academic interest. Thus, this fungus has a potential to be applied for biomass conversion to produce biofuel or other applications. In this study, the Biolog system was used to characterize the utilisation and growth of T. lanuginosus on 95 carbon sources. The carbohydrates based compounds, both single sugars and oligosaccharide, showed the best utilisation profile, with the pentose sugar xylose inducing the highest growth, followed by trehelose, raffinose, D-mannose turanose fructose and glucose. Among oligosaccharides, sucrose had the highest mycelium formation followed by stachyose, maltose, maltotriose, glycogen and dextrin. Interestingly the fungus also grew well on cellobiose suggesting that this fungus can produce cellulose hydrolysing proteins. D-alanine was the best amino acid to promote fungal growth while the effect of other amino acids tested was similar to the control. These results demonstrate the ability of this fungus to grow relatively well on most plant based compounds thus making this fungus a possible candidate for plant biomass conversion which can be applied to a number of biotechnological applications including biofuel production.展开更多
The sulfur-containing odor emitted from sludge composting could be controlled by sulfide oxidizing bacteria, yet mesophilic strains show inactivation during the thermophilic stage of composting. Aimed to investigate a...The sulfur-containing odor emitted from sludge composting could be controlled by sulfide oxidizing bacteria, yet mesophilic strains show inactivation during the thermophilic stage of composting. Aimed to investigate and characterize the thermotolerant bacterium that could oxidize sulfide into sulfate, a heterotrophic strain was isolated from sewage sludge composting and identified as Paenibacillus naphthalenovorans LYH-3. The effects of various environmental factors on sulfide oxidation capacities were studied to optimize the sulfate production, and the highest production rate (27.35%±0.86%) was obtained at pH 7.34, the rotation speed of 161.14 r/min, and the inoculation amount of 5.83%by employing BoxBehnken design. The results of serial sulfide substrates experiments indicated that strain LYH-3 could survive up to 400 mg/L of sulfide with the highest sulfide removal rate (88.79%±0.35%) obtained at 50 mg/L of sulfide. Growth kinetic analysis presented the maximum specific growth rateμm(0.5274 hr-1) after 22 hr cultivation at 50℃. The highest enzyme activities of sulfide quinone oxidoreductase (0.369±0.052 U/mg) and sulfur dioxygenase (0.255±0.014 U/mg) were both obtained at 40℃, and the highest enzyme activity of sulfite acceptor oxidoreductase (1.302±0.035 U/mg) was assessed at 50℃. The results indicated that P. naphthalenovorans possessed a rapid growth rate and efficient sulfide oxidation capacities under thermophilic conditions, promising a potential application in controlling sulfur-containing odors during the thermophilic stage of sludge composting.展开更多
Dry corn straw(DCS)is usually used in anaerobic digestion(AD),but fresh corn straw(FCS)has been given less consideration.In this study,the thermophilic AD of single-substrate(FCS and DCS)and co-digestion(straw with ca...Dry corn straw(DCS)is usually used in anaerobic digestion(AD),but fresh corn straw(FCS)has been given less consideration.In this study,the thermophilic AD of single-substrate(FCS and DCS)and co-digestion(straw with cattle manure)were investigated.The results show that when FCS was used as the single-substrate for AD,the methane production was 144 mL·g^(−1)·VS^(−1),which was 7.5%and 19.6%higher than that of single DCS and FCS with cattle manure,respectively.In addition,the structure of FCS was loose and coarse,which was easier to be degraded than DCS.At the hydrolysis and acidification stages,Clostridium_sensu_stricto_1,Clostridium_sensu_stricto_7 and Sporosarcina promoted the decomposition of organic matter,leading to volatile fatty acids(VFAs)accumulation.Methanosarcina(54.4%)activated multifunctional methanogenic pathways to avoid the VFAs inhibition,which was important at the CH_(4) production stage.The main pathway was hydrogenotrophic methanogenesis,with genes encoding formylmethanofuran dehydrogenase(K00200-K00203)and tetrahydromethanopterin Smethyltransferase(K00577-K00584).Methanosarcina also activated acetotrophic and methylotrophic methanogenesis pathways,with genes encoding acetyl phosphate(K13788)and methyl-coenzyme M reductase(K04480,K14080 and K14081),respectively.In the co-digestion,the methanogenic potential of FCS was also confirmed.This provides a scientific basis for regulating AD of crop straw.展开更多
Aerobic composting is a method for the sanitary disposal of human feces as is used in bio-toilet systems.As the products of composting can be utilized as a fertilizer,it would be beneficial if the composting condition...Aerobic composting is a method for the sanitary disposal of human feces as is used in bio-toilet systems.As the products of composting can be utilized as a fertilizer,it would be beneficial if the composting conditions could be more precisely controlled for the retention of fecal nitrogen as long as possible in the compost.In this study,batch experiments were conducted using a closed aerobic thermophilic composting reactor with sawdust as the bulk matrix to simulate the condition of a bio-toilet for the sanitary disposal of human feces.Attention was paid to the characteristics of nitrogen transformation.Under the controlled conditions of temperature at 60°C,moisture content at 60%,and a continuous air supply,more than 70%fecal organic removal was obtained,while merely 17%fecal nitrogen loss was observed over a two-week composting period.The nitrogen loss was found to occur mainly in the first 24 h with the rapid depletion of inorganic nitrogen but with an almost unchanged organic nitrogen content.The fecal NH4-N which was the main component of the inorganic nitrogen(>90%)decreased rapidly in the first day,decreased at a slower rate over the following days,and finally disappeared entirely.The depletion of NH4-N was accompanied by the accumulation of NH3 gas in the ammonia absorber connected to the reactor.A mass balance between the exhausted NH3 gas and the fecal NH4-N content in the first 24 hours indicated that the conversion of ammonium into gaseous ammonia was the main reason for nitrogen loss.Thermophilic composting could be considered as a way to keep a high organic nitrogen content in the compost for better utilization as a fertilizer.展开更多
A desulfurization strain that belongs to the thermophilic alkaline desulphuricant is designated as strain GDJ-3 and isolated from Inner Mongolia, China. The colony of the strain shows tiny, yellow, or white-yellow, an...A desulfurization strain that belongs to the thermophilic alkaline desulphuricant is designated as strain GDJ-3 and isolated from Inner Mongolia, China. The colony of the strain shows tiny, yellow, or white-yellow, and it becomes henna with the protracting of cultivated time. The cells are bacilliform (0.3 -0.6 × 1.0-1.2 μm), motive, and Gram negative. The strain GDJ-3 is able to utilize respectively the thiosulphate, sulfate, sulfite, or sulfide as sulfur source, utilize the carbon dioxide as the carbon source, and utilize the ammonium or nitrate as the nitrogen source. According to GenBank data, 16s RNA results of GDJ-3 are in good agreement with Alpha proteobacterrium sp. (97%) and Ochrobactrum sp. (98%). For GDJ-3, the optimum growth temperature is at 45℃, the optimum pH is at 8.5-8.8, and the optimum rocking speed of sorting table is at 150 r/min. Under the optimum culture condition, the cells of the strain can live for about 18 h. In the desulfurization solution, which is prepared according to the composition of DDS solution, the objectionable constituents of sodium thiosulphate and sodium sulfide were added factitiously, and the bacterial cell concentration was set at 107/mL. After the regeneration of the above desulfurization solution by the strain cells, the concentration of sodium thiosulphate was decreased by 14.75 g/L (percentage loss of content 13.21%), the concentration of sodium sulfide was decreased by 0.76 g/L (percentage loss of content 87.36%) in the desulfurization solution in 9.5 hours, and sulfur appeared. Maybe, this kind of strain can be used as the regeneration's bacterial source of DDS solution.展开更多
The gene coding for a thermophilic neutral protease from Bacillus stearothermophilus was expressed in Bacillus subtilis DB104, under the control of the sacB gene promoter. This was followed by either the native signal...The gene coding for a thermophilic neutral protease from Bacillus stearothermophilus was expressed in Bacillus subtilis DB104, under the control of the sacB gene promoter. This was followed by either the native signal peptide sequence of this protease or the signal peptide sequence of the sacB gene. The protease was purified 3.8-fold, with a specific activity of 16530 U mg-1. As analyzed by SDS-PAGE, the molecular mass of the expressed protease was about 35 kDa, and the optimal temperature and pH of the protease were 65℃ and 7.5, respectively. Moreover, it still had about 80% activity after 1 h reaction at 65 ℃ .展开更多
Biowaste valorization through anaerobic digestion is an attractive option to achieve both climate protection goals and renewable energy production.In this paper,a complete set of batch trials was carried out on kitche...Biowaste valorization through anaerobic digestion is an attractive option to achieve both climate protection goals and renewable energy production.In this paper,a complete set of batch trials was carried out on kitchen waste to investigate the effects of mild thermal pretreatment,temperature regimen and substrate/inoculum ratio.Thermal pretreatment was effective in the solubilisation of macromolecular fractions,particularly carbohydrates.The ability of the theoretical methodologies in estimating hydrogen and methane yields of complex substrates was evaluated by comparing the experimental results with the theoretical values.Despite the single batch configuration,a significant initial hydrogen production was observed,prior to methane yield.Main pretreatment effect was the gain in hydrogen production;the extent was highly variable according to the other parameters values.High hydrogen yields,up to 113 mL H2/g VSfed,were related to the prompt transformation of soluble sugars.Thermophilic regimen resulted,as expected,in faster digestions(up to 78 mL CH4/gVS/day) and sorted out pH inhibition.The relatively low methane yields(342-398 mL CH4/g VSfed) were the result of the consistent lignocellulosic content and low lipid content.Thermal pretreatment proved to be a promising option for the enhancement of hydrogen production in food waste dark fermentation.展开更多
Elimination of antibiotic resistance genes(ARGs)in animal manure from concentrated animal feeding operations by thermophilic composting has drawn increasing attention.This study investigated the effects of sawdust bio...Elimination of antibiotic resistance genes(ARGs)in animal manure from concentrated animal feeding operations by thermophilic composting has drawn increasing attention.This study investigated the effects of sawdust biochar,corn stover biochar and peanut hull biochar with three spiked levels on ARGs in swine manure during thermophilic composting.Thirteen ARGs corresponding to four classes of antibiotics(tetracyclines,sulfonamides,macrolides and quinolones)were determined in the composting piles.Results indicated that the ten tested composting groups became fully mature after 30-day thermophilic composting process.tetM,tetO and ermB were reduced in all tested groups;tetC and tetG,tetX,sul1,sul2,ermF,qnrD and aac(6’)-Ib were mostly reduced under low level biochar addition but increased under higher level biochar addition;gyrA increased under medium biochar addition and reduced in other groups;oqxB remained comparatively stable throughout the composting process.The addition levels of spiked biochar are more important than types of spiked biochar on the removal of ARGs in the composting pile.The average removal rates of ARGs in the control group,low,medium and high level biochar addition groups were 0.24 logs,0.52-0.72 logs,-0.52-0.18 logs and-0.19-0.21 logs,respectively.In summary,low level biochar addition could enhance the elimination of studied ARGs in swine manure during the composting process,while medium level biochar addition to the composting piles would increase the risk of ARGs’propagation.展开更多
We investigated the therapeutic effects of superoxide dismutase(SOD)from thermophilic bacterium HB27 on chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS)and its underlying mechanisms.A Sprague–Dawley rat mode...We investigated the therapeutic effects of superoxide dismutase(SOD)from thermophilic bacterium HB27 on chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS)and its underlying mechanisms.A Sprague–Dawley rat model of CP/CPPS was prepared and then administered saline or Thermus thermophilic(Tt)-SOD intragastrically for 4 weeks.Prostate inflammation and fibrosis were analyzed by hematoxylin and eosin staining,and Masson staining.Alanine transaminase(ALT),aspartate transaminase(AST),serum creatinine(CR),and blood urea nitrogen(BUN)levels were assayed for all animals.Enzyme-linked immunosorbent assays(ELISA)were performed to analyze serum cytokine concentrations and tissue levels of malondialdehyde,nitric oxide,SOD,catalase,and glutathione peroxidase.Reactive oxygen species levels were detected using dichlorofluorescein diacetate.The messenger ribonucleic acid(mRNA)expression of tissue cytokines was analyzed by reverse transcription polymerase chain reaction(RT-PCR),and infiltrating inflammatory cells were examined using immunohistochemistry.Nuclear factor-κB(NF-κB)P65,P38,and inhibitor of nuclear factor-κBα(I-κBα)protein levels were determined using western blot.Tt-SOD significantly improved histopathological changes in CP/CPPS,reduced inflammatory cell infiltration and fibrosis,increased pain threshold,and reduced the prostate index.Tt-SOD treatment showed no significant effect on ALT,AST,CR,or BUN levels.Furthermore,Tt-SOD reduced inflammatory cytokine expression in prostate tissue and increased antioxidant capacity.This anti-inflammatory activity correlated with decreases in the abundance of cluster of differentiation 3(CD3),cluster of differentiation 45(CD45),and macrophage inflammatory protein 1α(MIP1α)cells.Tt-SOD alleviated inflammation and oxidative stress by reducing NF-κB P65 and P38 protein levels and increasing I-κBαprotein levels.These findings support Tt-SOD as a potential drug for CP/CPPS.展开更多
Polyacrylamide(PAM)is generally employed in wastewater treatment processes such as sludge dewatering and therefore exists in the sludge.Furthermore,it degrades slowly and can deteriorate methane yield during anaerobic...Polyacrylamide(PAM)is generally employed in wastewater treatment processes such as sludge dewatering and therefore exists in the sludge.Furthermore,it degrades slowly and can deteriorate methane yield during anaerobic digestion(AD).The impact or fate of PAM in AD under thermophilic conditions is still unclear.This study mainly focuses on PAM degradation and enhanced methane production from PAM-added sludge during 15 days of thermophilic(55°C)AD compared to mesophilic(35°C)AD.Sludge and PAM dose from 10 to 50 g/kg TSS were used.The results showed that PAM degraded by 76%to 78%with acrylamide(AM)content of 0.2 to 3.3 mg/L in thermophilic AD.However,it degraded only 21%to 30%with AM content of 0.5 to 7.2 mg/L in mesophilic AD.The methane yield was almost 230 to 238.4 mL/g VSS on the 8th day in thermophilic AD but was 115.2 to 128.6 mL/g VSS in mesophilic AD.Mechanism investigation revealed that thermophilic AD with continuous stirring not only enhanced PAM degradation but also boosted the organics release from the sludge with added PAM and gave higher methane yield than mesophilic AD.展开更多
The occurrence frequencies of the dinucleotides of genes of three thermophilic and three mesophilic species from both archaea and eubacteria were investigated in this study. The genes encoding water soluble proteins w...The occurrence frequencies of the dinucleotides of genes of three thermophilic and three mesophilic species from both archaea and eubacteria were investigated in this study. The genes encoding water soluble proteins were rich in the dinucleotides of purine dimers, whereas the genes encoding membrane proteins were rich in pyrimidine dimers. The dinucleotides of purine dimers are the counterparts of pyrimidine dimers in a double-stranded DNA. The purine/pyrimidine dimers were favored in the thermophiles but not in the mesophiles, based on comparisons of observed and expected frequencies. This finding is in agreement with our previous study which showed that purine/pyrimidine dimers are positive factors that increase the thermal stability of DNA. The dinucleotides AA, AG, and GA are components of the codons of charged residues of Glu, Asp, Lys, and Arg, and the dinucleotides TT, CT, and TC are components of the codons of hydrophobic residues of Leu, Ile, and Phe. This is consistent with the suitabilities of the different amino acid residues for water soluble and membrane proteins. Our analysis provides a picture of how thermophilic species produce water soluble and membrane proteins with distinctive characters: the genes encoding water soluble proteins use DNA sequences rich in purine dimers, and the genes encoding membrane proteins use DNA sequences rich in pyrimidine dimers on the opposite strand.展开更多
Species of the genus Myceliophthora and its teleomorph Corynascus have attracted increasing interest due to their potential to produce thermostable enzymes.This study re-assessed the phylogenetic relationship of 49 is...Species of the genus Myceliophthora and its teleomorph Corynascus have attracted increasing interest due to their potential to produce thermostable enzymes.This study re-assessed the phylogenetic relationship of 49 isolates of nine species belonging to Myceliophthora and Corynascus.One species,M.vellerea,was shown not to belong to the genus Myceliophthora and should be placed in the genus Ctenomyces.The other species belonged to two phylogenetic clusters:mesophilic fungi with the type species M.lutea and C.sepedonium,and thermophilic fungi with M.thermophila,M.hinnulea and C.thermophilus.The phylogenetic data provides no clear separation of the two genera Corynascus and Myceliophthora.To avoid confusion in future taxonomic studies,it is proposed that all existing Corynascus species be renamed to Myceliophthora,which is the old name and the one more frequently used.Furthermore,this study identified two groups within the isolates listed as M.thermophila and assigned one group(five isolates)to M.heterothallica based on AFLP analysis and mating behavior.This study provides new insights into the genetic differences within the genus Myceliophthora and will therefore be essential for the interpretation of future genomic and physiological studies of these species.展开更多
A strain of extremely thermophilic, anaerobic, xylanolytic bacterium was isolated from the hot spring in Kangding County, Sichuan Province, and it was gram reaction negative, immobile, non sporeformative with its cell...A strain of extremely thermophilic, anaerobic, xylanolytic bacterium was isolated from the hot spring in Kangding County, Sichuan Province, and it was gram reaction negative, immobile, non sporeformative with its cells arranged single or in pairs, 0.7\1.0 μm wide and 2.0\5.0 μm long. After being cultured at 75℃ for 3 d on xylan agar rolling tube, its colonies were rounded, convex, smooth in margin and transparent, and could not produce pigments, but could produce carbon dioxide, hydrogen, lactic acid, acetic acid and trace ethanol during the fermentation of xylan.展开更多
We found U2R1,a previously discovered G-rich DNA sequence,could form the G-quadruplex(G4)structure at high tem-perature and maintain high stability.By utilizing its specific binding ability with the N-methylmesoporphy...We found U2R1,a previously discovered G-rich DNA sequence,could form the G-quadruplex(G4)structure at high tem-perature and maintain high stability.By utilizing its specific binding ability with the N-methylmesoporphyrin IX(NMM,a fluorescent probe),a thermophilic signal transduction unit was proposed,that was the NMM-U2R1 complex.Current methods for single nucleotide polymorphism(SNP)detection relying on the room-temperature rolling circle amplification system often suffered from poor accuracy,since the low temperature lowers the sensitivity for identifying the base mismatches.In this work,we combined the thermal stable signal transduction unit with the isothermal amplification reaction to develop a thermophilic fluorescent assay.High temperature could ensure the accuracy of base pairing.Based on this,this fluorescent assay has been successfully applied for the identification of one-or two-mismatched base DNA or microRNA 21.And it is expected to be generally applicable to identify SNPs in many other sequences.Furthermore,this work will open new opportunities for development of the thermally stable G4 DNA in biosensor.展开更多
A facultative thermophilic alkaline desulphuricant strain named GDJ-3 was isolated from neutral soils,enriched on sulfur synthetic medium,and detected in previous work.Conventional and chemotax-onomic analyses and 16s...A facultative thermophilic alkaline desulphuricant strain named GDJ-3 was isolated from neutral soils,enriched on sulfur synthetic medium,and detected in previous work.Conventional and chemotax-onomic analyses and 16s RNA gene sequencing showed that the strain was in good agreement with Alpha proteobacterium sp.(97%) and ochrobactrum sp.(98%).The regenerative processes of the solu-tion containing sulfur compounds(SCS) from the strain through an orthogonal test were investigated to get the optimum regenerative condition.The results showed that regenerative temperature,air flow,and stirring speed of the agitator were the main three variables influencing the regenerative processes of the SCS.The optimum regenerative efficiency of the SCS from the strain was obtained when tem-perature,air flow,and stirring speed of the agitator were 318.2 K,3.0 L/min,and zero r/min,respectively.Under this condition,when the cell concentration of the strain was adjusted to 107/mL,the concentra-tions of Na2S2O3 and Na2S in the SCS decreased from 112.68 g/L to 96.88 g/L and from 0.87 g/L to 0.11 g/L in 9.5 h.Meanwhile,XRD spectrum shows that sulfur was formed in the regeneration process.These results suggest that the strain has potential application to the regeneration of the industrial so-lution containing sulfur compounds.展开更多
文摘Composting as a solution to the increasing generation of municipal solid waste (MSW), also contribute to GHGs emission when not controlled and could lack some basic nutrients, especially nitrogen. This study assessed the split-additions of nitrogen-rich substrate to composting materials and their effect on GHGs emissions as well as the quality of the composts. Nitrogen-rich substrates formulated from pig and goat manure were co-composted with MSW for a 12-weeks period by split adding at mesophilic (˚C) and thermophilic (>50˚C) stages in five different treatments. Representative samples from the compost were taken from each treatment for physicochemical, heavy metals and bacteriological analysis. In-situ CH<sub>4</sub>, CO<sub>2</sub>, N<sub>2</sub>O gas emissions were also analyzed weekly during composting. It was observed that all the treatments showed significant organic matter decomposition, reaching thermophilic temperatures in the first week of composting. The absence affects the suitable agronomic properties. All nitrogen-rich substrate applied at thermophilic stage (Treatment two) recorded the highest N, P and K concentrations of 1.34%, 0.97% and 2.45%, respectively with highest nitrogen retention. In terms of GHG emissions, CO<sub>2</sub> was highest at the thermophilic stage when N-rich substrate was added in all treatment, while CH<sub>4</sub> was highest in the mesophilic stage with N-rich substrate addition. N<sub>2</sub>O showed no specific trend in the treatments. Split addition of the N-rich substrate for co-composting of MSW produced compost which is stable, has less nutrient loss and low GHG emissions. Split addition of a nitrogen-rich substrate could be an option for increasing the fertilizer value of MSW compost.
基金supported by the National Iranian Copper Industry Co.
文摘Mixed mesophilic and extreme thermophilic bioleaching were evaluated to remove copper from the molybdenite concentrate.Bioleaching tests were carried out in shake flasks and in a 50-L bioreactor.The shake flask tests were performed with different inoculum size,solids density,pH.and temperature in order to identify optimum conditions.The highest amount of copper elimination,75%was obtained with extreme thermophilic microorganisms(at 12%inoculation,10%solids,65℃and a pH of 1.5).The highest copper elimination by mesophilic microorganisms was 55%(at 12%inoculation,5%solids,30℃at pH 2).The optimum conditions in shake flask tests were applied to 7 days batch tests in a50-L bioreactor.Extreme thermophilic experiment gave the best copper elimination of 60%(at 12%inoculation,10%solids,65℃and pH 1.5).Mesophilic test removed 50%of the copper(at 12%inoculation,10%solids,35℃at pH 2).
文摘Creosote is used for preservation of railway ties and timbers, electric utility poles, marine and foundation piling, fences and garden furniture. Creosote-treated wood waste may cause potential contamination of soil and water if they are not disposed properly. Creosote contains over 300 organic compounds including polycyclic aromatic hydrocarbons, phenolic compounds and heterocyclic organic compounds, many of which are toxic to human and can cause damage to kidney, liver, eyes and skin. The feasibility of using a composting technique inoculated with the cellulose degrading actinomycetesThermobifidafusca as a mesophilic/thermophilic bioremediation option to degrade phenolic compounds in creosote treated wood waste was evaluated. The temperature profile of bioremediation process clearly identified mesophilic and thermophilic phases in both experiments. Different degradation rates were observed in the mesophilic and thermophilic phases. Fluctuations of pH was observed in both experiment as the result of the breakdown of organic nitrogen to ammonium in the first week and the formation of organic acids and the loss of ammonium with the exhaust gases in the latter stage. The moisture content decreased in both trials because of the net loss of water with the exhaust gas. Both experiments achieved similar reductions in total carbon and TKN, volatile solids and phenolic compounds, cellulose and lignin indicating similar levels of microbial activities during the composting process. The stability and maturity of the final products were also similar. The inoculation of the cellulolytic-thermophilicactinomycetesThermobifidafusca did not manifest observable differences in degrading cellulose, lignin and phenolic compounds compared with the control.
文摘Hydrogen production from palm oil mill effluent (POME) by Thermoanaerobacterium thermosaccharolyticum PSU-2 was investigated both in batch and continuous reactors using anaerobic sequencing batch reactor (ASBR) and continuous stirred tank reactor (CSTR). The hydrogen production determined from batch experiment of POME at an inoculum size of 0%, 10%, 20% and 30% (v/v) was 161, 201, 246 and 296 mL H2/g-COD with COD removal efficiency of 21%, 23%, 23% and 23%, respectively. Continuous hydrogen production was start-up with 30% (v/v) inoculum in both ASBR and CSTR reactors and more than 30% COD removal could be obtained at HRT of 4 days, corresponding to OLR of 11.3 g COD/ L·day. Similar hydrogen production rates of 2.05 and2.16 LH2/L. day were obtained from ASBR and CSTR, respectively. COD removal efficiency of ASBR was 37.7%, while it was 44.8% for CSTR. However, ASBR was stable in term of alkalinity, while the CSTR was stable in term of hydrogen production, soluble metabolites concentration and alkalinity. Therefore, the CSTR was found to be more stable in hydrogen production than ASBR under the same OLR.
文摘The paper provides a critical comparison between mesophilic and thermophilic anaerobic treatment of PTA wastewater through diagnosis of a case study. Aspects covered are bioavailability, biodegradability, microbial population, thermodynamics, kinetics involved and bio-reactor design for PTA wastewater treatment. The results of the case study suggests that one- stage thermophilic anaerobic reactor coupled with coagulation-flocculation pre-treatment unit and an aerobic post treatment unit could be techno-economically viable for PTA wastewater treatment to ensure that the final effluent quality conforms to the international standard. The in-formation emanated from this study could be useful and thought provoking to the professionals and academia in the area of PTA wastewater treatment and can serve as impetus toward the development of research lines in similar problems like the treatment of other petrochemical wastewater such as phenol-con- taining wastewater, benzene/benzoic acid-con- taining wastewater or wastewater from other similar industrial settings.
文摘The thermophilic filamentous fungus, Thermomyces lanuginosus produces the largest amount of xylanase reported. In addition to this, it expresses large amount of other enzymes that have been used industrially or have academic interest. Thus, this fungus has a potential to be applied for biomass conversion to produce biofuel or other applications. In this study, the Biolog system was used to characterize the utilisation and growth of T. lanuginosus on 95 carbon sources. The carbohydrates based compounds, both single sugars and oligosaccharide, showed the best utilisation profile, with the pentose sugar xylose inducing the highest growth, followed by trehelose, raffinose, D-mannose turanose fructose and glucose. Among oligosaccharides, sucrose had the highest mycelium formation followed by stachyose, maltose, maltotriose, glycogen and dextrin. Interestingly the fungus also grew well on cellobiose suggesting that this fungus can produce cellulose hydrolysing proteins. D-alanine was the best amino acid to promote fungal growth while the effect of other amino acids tested was similar to the control. These results demonstrate the ability of this fungus to grow relatively well on most plant based compounds thus making this fungus a possible candidate for plant biomass conversion which can be applied to a number of biotechnological applications including biofuel production.
基金supported by the National Natural Science Foundation of China(No. 51878216)。
文摘The sulfur-containing odor emitted from sludge composting could be controlled by sulfide oxidizing bacteria, yet mesophilic strains show inactivation during the thermophilic stage of composting. Aimed to investigate and characterize the thermotolerant bacterium that could oxidize sulfide into sulfate, a heterotrophic strain was isolated from sewage sludge composting and identified as Paenibacillus naphthalenovorans LYH-3. The effects of various environmental factors on sulfide oxidation capacities were studied to optimize the sulfate production, and the highest production rate (27.35%±0.86%) was obtained at pH 7.34, the rotation speed of 161.14 r/min, and the inoculation amount of 5.83%by employing BoxBehnken design. The results of serial sulfide substrates experiments indicated that strain LYH-3 could survive up to 400 mg/L of sulfide with the highest sulfide removal rate (88.79%±0.35%) obtained at 50 mg/L of sulfide. Growth kinetic analysis presented the maximum specific growth rateμm(0.5274 hr-1) after 22 hr cultivation at 50℃. The highest enzyme activities of sulfide quinone oxidoreductase (0.369±0.052 U/mg) and sulfur dioxygenase (0.255±0.014 U/mg) were both obtained at 40℃, and the highest enzyme activity of sulfite acceptor oxidoreductase (1.302±0.035 U/mg) was assessed at 50℃. The results indicated that P. naphthalenovorans possessed a rapid growth rate and efficient sulfide oxidation capacities under thermophilic conditions, promising a potential application in controlling sulfur-containing odors during the thermophilic stage of sludge composting.
基金supported by the Shaanxi Youth Thousand Talents Project(A279021901)the Scientific and Technological Activities for Overseas Researchers in Shaanxi Province(20200002)+3 种基金the Chinese Universities Scientific Fund(2452021112)the Key Research and Development Project of Shaanxi Province(2020NY-114)the Double first-class construction project funded by Northwest A&F University,Northwest A&F University Young Talent Project(Z111021902)the USA Energy Foundation(G-2206-33957).
文摘Dry corn straw(DCS)is usually used in anaerobic digestion(AD),but fresh corn straw(FCS)has been given less consideration.In this study,the thermophilic AD of single-substrate(FCS and DCS)and co-digestion(straw with cattle manure)were investigated.The results show that when FCS was used as the single-substrate for AD,the methane production was 144 mL·g^(−1)·VS^(−1),which was 7.5%and 19.6%higher than that of single DCS and FCS with cattle manure,respectively.In addition,the structure of FCS was loose and coarse,which was easier to be degraded than DCS.At the hydrolysis and acidification stages,Clostridium_sensu_stricto_1,Clostridium_sensu_stricto_7 and Sporosarcina promoted the decomposition of organic matter,leading to volatile fatty acids(VFAs)accumulation.Methanosarcina(54.4%)activated multifunctional methanogenic pathways to avoid the VFAs inhibition,which was important at the CH_(4) production stage.The main pathway was hydrogenotrophic methanogenesis,with genes encoding formylmethanofuran dehydrogenase(K00200-K00203)and tetrahydromethanopterin Smethyltransferase(K00577-K00584).Methanosarcina also activated acetotrophic and methylotrophic methanogenesis pathways,with genes encoding acetyl phosphate(K13788)and methyl-coenzyme M reductase(K04480,K14080 and K14081),respectively.In the co-digestion,the methanogenic potential of FCS was also confirmed.This provides a scientific basis for regulating AD of crop straw.
基金the National Natural Science Foundation of China(Grant No.51021140002)the National Program of Water Pollution Control(No.2008ZX07317-004)the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT0853)。
文摘Aerobic composting is a method for the sanitary disposal of human feces as is used in bio-toilet systems.As the products of composting can be utilized as a fertilizer,it would be beneficial if the composting conditions could be more precisely controlled for the retention of fecal nitrogen as long as possible in the compost.In this study,batch experiments were conducted using a closed aerobic thermophilic composting reactor with sawdust as the bulk matrix to simulate the condition of a bio-toilet for the sanitary disposal of human feces.Attention was paid to the characteristics of nitrogen transformation.Under the controlled conditions of temperature at 60°C,moisture content at 60%,and a continuous air supply,more than 70%fecal organic removal was obtained,while merely 17%fecal nitrogen loss was observed over a two-week composting period.The nitrogen loss was found to occur mainly in the first 24 h with the rapid depletion of inorganic nitrogen but with an almost unchanged organic nitrogen content.The fecal NH4-N which was the main component of the inorganic nitrogen(>90%)decreased rapidly in the first day,decreased at a slower rate over the following days,and finally disappeared entirely.The depletion of NH4-N was accompanied by the accumulation of NH3 gas in the ammonia absorber connected to the reactor.A mass balance between the exhausted NH3 gas and the fecal NH4-N content in the first 24 hours indicated that the conversion of ammonium into gaseous ammonia was the main reason for nitrogen loss.Thermophilic composting could be considered as a way to keep a high organic nitrogen content in the compost for better utilization as a fertilizer.
文摘A desulfurization strain that belongs to the thermophilic alkaline desulphuricant is designated as strain GDJ-3 and isolated from Inner Mongolia, China. The colony of the strain shows tiny, yellow, or white-yellow, and it becomes henna with the protracting of cultivated time. The cells are bacilliform (0.3 -0.6 × 1.0-1.2 μm), motive, and Gram negative. The strain GDJ-3 is able to utilize respectively the thiosulphate, sulfate, sulfite, or sulfide as sulfur source, utilize the carbon dioxide as the carbon source, and utilize the ammonium or nitrate as the nitrogen source. According to GenBank data, 16s RNA results of GDJ-3 are in good agreement with Alpha proteobacterrium sp. (97%) and Ochrobactrum sp. (98%). For GDJ-3, the optimum growth temperature is at 45℃, the optimum pH is at 8.5-8.8, and the optimum rocking speed of sorting table is at 150 r/min. Under the optimum culture condition, the cells of the strain can live for about 18 h. In the desulfurization solution, which is prepared according to the composition of DDS solution, the objectionable constituents of sodium thiosulphate and sodium sulfide were added factitiously, and the bacterial cell concentration was set at 107/mL. After the regeneration of the above desulfurization solution by the strain cells, the concentration of sodium thiosulphate was decreased by 14.75 g/L (percentage loss of content 13.21%), the concentration of sodium sulfide was decreased by 0.76 g/L (percentage loss of content 87.36%) in the desulfurization solution in 9.5 hours, and sulfur appeared. Maybe, this kind of strain can be used as the regeneration's bacterial source of DDS solution.
基金Supported by the "863" High-Tech Research Project of China (Grant No. 2007AA 02Z212)
文摘The gene coding for a thermophilic neutral protease from Bacillus stearothermophilus was expressed in Bacillus subtilis DB104, under the control of the sacB gene promoter. This was followed by either the native signal peptide sequence of this protease or the signal peptide sequence of the sacB gene. The protease was purified 3.8-fold, with a specific activity of 16530 U mg-1. As analyzed by SDS-PAGE, the molecular mass of the expressed protease was about 35 kDa, and the optimal temperature and pH of the protease were 65℃ and 7.5, respectively. Moreover, it still had about 80% activity after 1 h reaction at 65 ℃ .
基金supported by PRIN 2012 project titled "Advanced processes to convert organic wastes in innovative, sustainable and useful products" co-financed by the Italian Minister of University and Scientific Research (MIUR).
文摘Biowaste valorization through anaerobic digestion is an attractive option to achieve both climate protection goals and renewable energy production.In this paper,a complete set of batch trials was carried out on kitchen waste to investigate the effects of mild thermal pretreatment,temperature regimen and substrate/inoculum ratio.Thermal pretreatment was effective in the solubilisation of macromolecular fractions,particularly carbohydrates.The ability of the theoretical methodologies in estimating hydrogen and methane yields of complex substrates was evaluated by comparing the experimental results with the theoretical values.Despite the single batch configuration,a significant initial hydrogen production was observed,prior to methane yield.Main pretreatment effect was the gain in hydrogen production;the extent was highly variable according to the other parameters values.High hydrogen yields,up to 113 mL H2/g VSfed,were related to the prompt transformation of soluble sugars.Thermophilic regimen resulted,as expected,in faster digestions(up to 78 mL CH4/gVS/day) and sorted out pH inhibition.The relatively low methane yields(342-398 mL CH4/g VSfed) were the result of the consistent lignocellulosic content and low lipid content.Thermal pretreatment proved to be a promising option for the enhancement of hydrogen production in food waste dark fermentation.
基金The project was financially supported by the National Key R&D Program of China(2017YFD0800800).
文摘Elimination of antibiotic resistance genes(ARGs)in animal manure from concentrated animal feeding operations by thermophilic composting has drawn increasing attention.This study investigated the effects of sawdust biochar,corn stover biochar and peanut hull biochar with three spiked levels on ARGs in swine manure during thermophilic composting.Thirteen ARGs corresponding to four classes of antibiotics(tetracyclines,sulfonamides,macrolides and quinolones)were determined in the composting piles.Results indicated that the ten tested composting groups became fully mature after 30-day thermophilic composting process.tetM,tetO and ermB were reduced in all tested groups;tetC and tetG,tetX,sul1,sul2,ermF,qnrD and aac(6’)-Ib were mostly reduced under low level biochar addition but increased under higher level biochar addition;gyrA increased under medium biochar addition and reduced in other groups;oqxB remained comparatively stable throughout the composting process.The addition levels of spiked biochar are more important than types of spiked biochar on the removal of ARGs in the composting pile.The average removal rates of ARGs in the control group,low,medium and high level biochar addition groups were 0.24 logs,0.52-0.72 logs,-0.52-0.18 logs and-0.19-0.21 logs,respectively.In summary,low level biochar addition could enhance the elimination of studied ARGs in swine manure during the composting process,while medium level biochar addition to the composting piles would increase the risk of ARGs’propagation.
基金supported by the Medical Scientific Research Foundation of Zhejiang Province(2021RC129,2019KY694)the National Natural Science Foundation of China(82000230)+1 种基金the Jiaxing Medical Key Subject Funding of Zhejiang Province(2019-zc-07)the Jiaxing Key Laboratory of Precise Diagnosis and Treatment of Urological Tumor(2020-mnzdsys).
文摘We investigated the therapeutic effects of superoxide dismutase(SOD)from thermophilic bacterium HB27 on chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS)and its underlying mechanisms.A Sprague–Dawley rat model of CP/CPPS was prepared and then administered saline or Thermus thermophilic(Tt)-SOD intragastrically for 4 weeks.Prostate inflammation and fibrosis were analyzed by hematoxylin and eosin staining,and Masson staining.Alanine transaminase(ALT),aspartate transaminase(AST),serum creatinine(CR),and blood urea nitrogen(BUN)levels were assayed for all animals.Enzyme-linked immunosorbent assays(ELISA)were performed to analyze serum cytokine concentrations and tissue levels of malondialdehyde,nitric oxide,SOD,catalase,and glutathione peroxidase.Reactive oxygen species levels were detected using dichlorofluorescein diacetate.The messenger ribonucleic acid(mRNA)expression of tissue cytokines was analyzed by reverse transcription polymerase chain reaction(RT-PCR),and infiltrating inflammatory cells were examined using immunohistochemistry.Nuclear factor-κB(NF-κB)P65,P38,and inhibitor of nuclear factor-κBα(I-κBα)protein levels were determined using western blot.Tt-SOD significantly improved histopathological changes in CP/CPPS,reduced inflammatory cell infiltration and fibrosis,increased pain threshold,and reduced the prostate index.Tt-SOD treatment showed no significant effect on ALT,AST,CR,or BUN levels.Furthermore,Tt-SOD reduced inflammatory cytokine expression in prostate tissue and increased antioxidant capacity.This anti-inflammatory activity correlated with decreases in the abundance of cluster of differentiation 3(CD3),cluster of differentiation 45(CD45),and macrophage inflammatory protein 1α(MIP1α)cells.Tt-SOD alleviated inflammation and oxidative stress by reducing NF-κB P65 and P38 protein levels and increasing I-κBαprotein levels.These findings support Tt-SOD as a potential drug for CP/CPPS.
基金The present work was supported by Key Program of the National Natural Science Foundation China(No.41773082,41573065)the National Key Research project on Water Environment Pollution Control in China(No.2017ZX07202002).
文摘Polyacrylamide(PAM)is generally employed in wastewater treatment processes such as sludge dewatering and therefore exists in the sludge.Furthermore,it degrades slowly and can deteriorate methane yield during anaerobic digestion(AD).The impact or fate of PAM in AD under thermophilic conditions is still unclear.This study mainly focuses on PAM degradation and enhanced methane production from PAM-added sludge during 15 days of thermophilic(55°C)AD compared to mesophilic(35°C)AD.Sludge and PAM dose from 10 to 50 g/kg TSS were used.The results showed that PAM degraded by 76%to 78%with acrylamide(AM)content of 0.2 to 3.3 mg/L in thermophilic AD.However,it degraded only 21%to 30%with AM content of 0.5 to 7.2 mg/L in mesophilic AD.The methane yield was almost 230 to 238.4 mL/g VSS on the 8th day in thermophilic AD but was 115.2 to 128.6 mL/g VSS in mesophilic AD.Mechanism investigation revealed that thermophilic AD with continuous stirring not only enhanced PAM degradation but also boosted the organics release from the sludge with added PAM and gave higher methane yield than mesophilic AD.
文摘The occurrence frequencies of the dinucleotides of genes of three thermophilic and three mesophilic species from both archaea and eubacteria were investigated in this study. The genes encoding water soluble proteins were rich in the dinucleotides of purine dimers, whereas the genes encoding membrane proteins were rich in pyrimidine dimers. The dinucleotides of purine dimers are the counterparts of pyrimidine dimers in a double-stranded DNA. The purine/pyrimidine dimers were favored in the thermophiles but not in the mesophiles, based on comparisons of observed and expected frequencies. This finding is in agreement with our previous study which showed that purine/pyrimidine dimers are positive factors that increase the thermal stability of DNA. The dinucleotides AA, AG, and GA are components of the codons of charged residues of Glu, Asp, Lys, and Arg, and the dinucleotides TT, CT, and TC are components of the codons of hydrophobic residues of Leu, Ile, and Phe. This is consistent with the suitabilities of the different amino acid residues for water soluble and membrane proteins. Our analysis provides a picture of how thermophilic species produce water soluble and membrane proteins with distinctive characters: the genes encoding water soluble proteins use DNA sequences rich in purine dimers, and the genes encoding membrane proteins use DNA sequences rich in pyrimidine dimers on the opposite strand.
基金supported by the EC 7th Framework program(NEMO,Project Grant agreement 222699).
文摘Species of the genus Myceliophthora and its teleomorph Corynascus have attracted increasing interest due to their potential to produce thermostable enzymes.This study re-assessed the phylogenetic relationship of 49 isolates of nine species belonging to Myceliophthora and Corynascus.One species,M.vellerea,was shown not to belong to the genus Myceliophthora and should be placed in the genus Ctenomyces.The other species belonged to two phylogenetic clusters:mesophilic fungi with the type species M.lutea and C.sepedonium,and thermophilic fungi with M.thermophila,M.hinnulea and C.thermophilus.The phylogenetic data provides no clear separation of the two genera Corynascus and Myceliophthora.To avoid confusion in future taxonomic studies,it is proposed that all existing Corynascus species be renamed to Myceliophthora,which is the old name and the one more frequently used.Furthermore,this study identified two groups within the isolates listed as M.thermophila and assigned one group(five isolates)to M.heterothallica based on AFLP analysis and mating behavior.This study provides new insights into the genetic differences within the genus Myceliophthora and will therefore be essential for the interpretation of future genomic and physiological studies of these species.
文摘A strain of extremely thermophilic, anaerobic, xylanolytic bacterium was isolated from the hot spring in Kangding County, Sichuan Province, and it was gram reaction negative, immobile, non sporeformative with its cells arranged single or in pairs, 0.7\1.0 μm wide and 2.0\5.0 μm long. After being cultured at 75℃ for 3 d on xylan agar rolling tube, its colonies were rounded, convex, smooth in margin and transparent, and could not produce pigments, but could produce carbon dioxide, hydrogen, lactic acid, acetic acid and trace ethanol during the fermentation of xylan.
基金financially supported by the National Natural Science Foundation of China (21922601, 51808096)Liaoning Revitalization Talents Program (XLYC1807080)the Fundamental Research Funds for the Central Universities (DUT20YG123)
文摘We found U2R1,a previously discovered G-rich DNA sequence,could form the G-quadruplex(G4)structure at high tem-perature and maintain high stability.By utilizing its specific binding ability with the N-methylmesoporphyrin IX(NMM,a fluorescent probe),a thermophilic signal transduction unit was proposed,that was the NMM-U2R1 complex.Current methods for single nucleotide polymorphism(SNP)detection relying on the room-temperature rolling circle amplification system often suffered from poor accuracy,since the low temperature lowers the sensitivity for identifying the base mismatches.In this work,we combined the thermal stable signal transduction unit with the isothermal amplification reaction to develop a thermophilic fluorescent assay.High temperature could ensure the accuracy of base pairing.Based on this,this fluorescent assay has been successfully applied for the identification of one-or two-mismatched base DNA or microRNA 21.And it is expected to be generally applicable to identify SNPs in many other sequences.Furthermore,this work will open new opportunities for development of the thermally stable G4 DNA in biosensor.
基金Supported by Yongfeng Boyuan Industry Co., Ltd., Jiangxi Province, China
文摘A facultative thermophilic alkaline desulphuricant strain named GDJ-3 was isolated from neutral soils,enriched on sulfur synthetic medium,and detected in previous work.Conventional and chemotax-onomic analyses and 16s RNA gene sequencing showed that the strain was in good agreement with Alpha proteobacterium sp.(97%) and ochrobactrum sp.(98%).The regenerative processes of the solu-tion containing sulfur compounds(SCS) from the strain through an orthogonal test were investigated to get the optimum regenerative condition.The results showed that regenerative temperature,air flow,and stirring speed of the agitator were the main three variables influencing the regenerative processes of the SCS.The optimum regenerative efficiency of the SCS from the strain was obtained when tem-perature,air flow,and stirring speed of the agitator were 318.2 K,3.0 L/min,and zero r/min,respectively.Under this condition,when the cell concentration of the strain was adjusted to 107/mL,the concentra-tions of Na2S2O3 and Na2S in the SCS decreased from 112.68 g/L to 96.88 g/L and from 0.87 g/L to 0.11 g/L in 9.5 h.Meanwhile,XRD spectrum shows that sulfur was formed in the regeneration process.These results suggest that the strain has potential application to the regeneration of the industrial so-lution containing sulfur compounds.
