Many microorganisms can dissolve the insoluble phosphates like apatite. However, the mechanisms are still not clear. This study was an attempt to investigate the mechanisms of rock phosphate solubilization by an Asper...Many microorganisms can dissolve the insoluble phosphates like apatite. However, the mechanisms are still not clear. This study was an attempt to investigate the mechanisms of rock phosphate solubilization by an Aspergillus 2TCiF2 and an Arthrobacter1TCRi7. The results indicated that the fungus produced a large amount of organic acids, mainly oxalic acid. The total quantity of the organic acids produced by the fungus was 550 times higher than that by the bacterium. Different organic acids had completely different capacities to solubilize the rock. Oxalic acid and citric acid had stronger capacity to dissolve the rock than malic acid, tartaric acid, lactic acid, acetic acid, malonic acid and succinic acid. The fungus solubilized the rock through excreting both proton and organic acids. The rock solubilization of the bacterium depended on only proton.展开更多
Reducing the oil-water interfacial tension(IFT)to ultra-low is believed the primary mechanism for surfactant-based enhanced oil recovery(EOR)process.However,field trials have shown that low concentration surfactant fl...Reducing the oil-water interfacial tension(IFT)to ultra-low is believed the primary mechanism for surfactant-based enhanced oil recovery(EOR)process.However,field trials have shown that low concentration surfactant flooding can also improve oil recovery without ultra-low IFT.To clarify the mechanism behind,the currently-used surfactant,naphthenic arylsulfonate(NAS),was used to unravel its function during surfactant flooding from the horizon of micron-and nano-scale.The solubilization capacity of NAS micelle to petroleum fractions was evaluated through light absorbance strategy,smallangle neutron scattering,dynamic light scattering and transmission electron microscopy.It was found that micellar solubilization plays a significant role during the surfactant flooding.In-situ emulsification was visualized in microfluidics with three types of microchips,respectively.A series of displacement tests were carried out with NAS solution pumping into oil-saturated chip.The results show that in-situ emulsification improve oil recovery mainly through blocking and entrainment effects.Results from this work aid in understanding the interaction between surfactant solution and petroleum fractions at low surfactant concentration,which is helpful for design surfactant-based displacing system for EOR process.展开更多
Plants need phosphorus for many physiological activities in a form of phosphate anions. Three different bacterial strains (Bacillus subtilis PH, Serratia marcescens PH1, and Serratia marcescens PH2), recently isolated...Plants need phosphorus for many physiological activities in a form of phosphate anions. Three different bacterial strains (Bacillus subtilis PH, Serratia marcescens PH1, and Serratia marcescens PH2), recently isolated from tomato plant rhizosphere, have high phosphate solubilization index (SI from 2.8 to 3.2) on Pikovskaya agar medium (which contains calcium phosphate). Moreover, phosphate release from calcium in Pikovskaya broth over 5 days is increasing with cell growth for the different isolates. The most efficient phosphate solubilization case is the mixed culture of the 3 strains (OD475 is almost 1). On the other hand, pH values decreased dramatically with time due to organic acids secretion and the maximum acidification level is recoded for Serratia marcescens PH2 (pH = 1.94). Interestingly, the isolates are resistance to important pesticides (oxamyl, thiophanate methyl, and captan) that are commonly used in the sampling area. This resistance is very favorable and increases the persistence of the phosphate solubilizing bacteria in contaminated soils. The isolates are therefore plant symbionts and growth promoting agents.展开更多
The ability to solubilize insoluble inorganic pho- sphate compounds by Gluconacetobacter diazotrophicus was studied using different cul-ture approaches. Qualitative plate assays using tricalcium phosphate as the sole ...The ability to solubilize insoluble inorganic pho- sphate compounds by Gluconacetobacter diazotrophicus was studied using different cul-ture approaches. Qualitative plate assays using tricalcium phosphate as the sole P-source showed that G. diazotrophicus produced solu-bilization only when aldoses were used as the C-source. Extracellular aldose oxidation via a pyrroloquinoline quinone-linked glucose dehy-drogenase (PQQ-GDH) is the main pathway for glucose metabolism in G. diazotrophicus. In batch cultures with 5 g l-1 of hydroxyapatite as the P-source and glucose as the C-source, more than 98% of insoluble P was solubilized. No solubilization was observed neither using glyc-erol nor culturing a PQQ-GDH mutant of G. di-azotrophicus. Solubilizaton was not affected by adding 100 mmol l-1 of MES buffer. Continuous cultures of G. diazotrophicus showed significant activities of PQQ-GDH either under C or P limi-tation. An intense acidification in the root envi-ronment of tomato and wheat seedlings inocu-lated with a G. diazotrophicus PAL5 was ob-served. Seedlings inoculated with a PQQ-GDH mutant strain of G. diazotrophicus showed no acidification. Our results suggest that G. di-azotrophicus is an excellent candidate to be used as biofertilizer because in addition to the already described plant growth-promoting abili-ties of this organism, it shows a significant mineral phosphate solubilization capacity.展开更多
Rock phosphate (RP) is a low efficient P fertilizer when directly used in the soil. Phosphate-solubilizing microorganisms (PSMs) can solubilize RP in fermentation or soil condition. The effect of different concentrati...Rock phosphate (RP) is a low efficient P fertilizer when directly used in the soil. Phosphate-solubilizing microorganisms (PSMs) can solubilize RP in fermentation or soil condition. The effect of different concentration of lanthanum (La) on the solubilization of RP was investigated by two isolates of phosphate-solubilizing fungi (PSF) Aspergillus niger P39 and Penicillium oxalicum P66 in liquid culture. Experimental results show that relatively higher concentration of La in the culture solution inhibites fungal growth and delays RP solubilizing activity of two isolates. This inhibitory effect of La on RP solubilization varies with PSF (isolate P66 is more sensitive to La than P39 in this experiment). Comparing the pH value of culture media with soluble P content as affected by La application, only within individual isolate not different isolates the negatively significant relationship was observed.展开更多
2Hydroxy1,4napthoquinone(lawsone)natural redorange dye was extracted from fresh henna(Lawsonia inermis)leaves in an alkaline media.The lawsonesurfactant solubilization constants(KLS)were calculated for the first time ...2Hydroxy1,4napthoquinone(lawsone)natural redorange dye was extracted from fresh henna(Lawsonia inermis)leaves in an alkaline media.The lawsonesurfactant solubilization constants(KLS)were calculated for the first time by using cationic cetyltrimethylammonium bromide(CTAB)and anionic sodium dodecyl sulphate(SDS).The standard free energy,concentration of solubilized lawsone and number of lawsone molecules solubilized into micelles were calculated and discussed.Surface excess,minimum surface area per molecule,surface pressure,free energy(adsorption and aggregation)and equilibrium constants of different states were determined from tensiometry.Different metal ions(Ag^(+),Co^(2+),Cu^(2+),Ni^(2+),Fe^(3+),Zn^(2+)and Al^(3+)were used to determine the complex forming ability with lawsone.Out of these,Ag+ions have strong binding capacity with lawsone.The adsorption of lawsone on the surface of glass with silver ions in presence of CTAB was also observed at pH>9.0.The pseudofirst,secondorder kinetic equation,intraparticles diffusion and Elovich models were used to determine the kinetics of lawsone adsorption onto the surface of glass and a probable mechanism has been discussed.Lawsone adsorption followed secondorder kinetic equation(k_(2)=0.019 g·mg^(1)·min^(1)).展开更多
Experimental data are presented on the enhanced solubilities of fluorene (FLR) resulting from solubilization in aqueous solutions of two conventional surfactants: cationic cetyltrimethylammonium bromide (CTAB) , anion...Experimental data are presented on the enhanced solubilities of fluorene (FLR) resulting from solubilization in aqueous solutions of two conventional surfactants: cationic cetyltrimethylammonium bromide (CTAB) , anionic sodium dodecyl sulfate (SDS), nonioinic polyethylene glycol dodecyl ether (Brij35) and a cationic gemini bis (hexadecyldimethylammonium) pentane dibromide (G5). The critical micellar concentration of surfactants was determined by surface tension measurements and aqueous solubilities of fluorene compound in surfactant solutions were measured spectrophotometrically. Solubilization of PAH compound commenced at the surfactant critical micelle concentration and was proportional to the concentration of surfactant in micelle. The results of the mixed systems were analyzed with the help of regular solution theory, in which the deviation of CMCexp values for mixed surfactant systems from CMCideal was measured by evaluating the interaction parameter, βm. Negative values of βm were observed in all equimolar binary systems which show synergism in the mixed micelle. Attraction force between two oppositely charged head groups lead the strongest synergism effect between cationic gemini and anionic conventional surfactant. In addition to molar solubilization ratio (MSR) solubilization efficiency is also quantified in terms of micelle-water partition coefficient (Km).展开更多
The dependence of solubilization properties on the alkyl chain length of alkyl glucosides (AG) in AG/isooctane/ n-butanol/water system was investigated. The stable Winsor II system consisting of a water-in-oil (w/o) m...The dependence of solubilization properties on the alkyl chain length of alkyl glucosides (AG) in AG/isooctane/ n-butanol/water system was investigated. The stable Winsor II system consisting of a water-in-oil (w/o) microemulsion phase and an aqueous phase was formed in AG/isooctane/n-butanol/water system. The apparent critical micelle concentration of AG reverse micelles in organic phases was markedly dependent upon the alkyl chain length of AG. The limiting amount of solubilized water increased with an increase in the alkyl chain length of AG. The solubilization capacity of methyl orange (MO) was superior to that of methylene blue (MB), and the solubilization capacities of MO and MB tended to increase with increasing the alkyl chain length of AG. Reverse micelles of dodecyl glucoside (AG12) exhibited the significant solubilization capacities of cytochrome c and lysozyme, while ribonuclease A was not solubilized by AG12 reverse micelles.展开更多
The partitioning of two non-steroidal anti-inflammatory drugs (NSAIDs), flurbiprofen and ketoprofen, into cationic cetyltrimethylammonium micelles was investigated using semi-equilibrium dialysis at 37℃ in phosphate ...The partitioning of two non-steroidal anti-inflammatory drugs (NSAIDs), flurbiprofen and ketoprofen, into cationic cetyltrimethylammonium micelles was investigated using semi-equilibrium dialysis at 37℃ in phosphate buffered saline. The micellar-water solubilization equilibrium constants for both NSAIDs, in their deprotonated forms, were observed to decrease linearly with increasing mole fraction of drug in micelles. For flurbiprofen, the solubilization constant in the limit as mole fraction of drug in micelles approaches zero was found to be 11,200 (co = 1 M), while for ketoprofen the value was 1950 (co = 1 M). Using 1H-NMR and UV spectroscopic techniques, the locus of solubilization for ketoprofen was found to be towards the charged exterior of the micelles, in the Stern layer, whereas flurbiprofen was found to solubilize more in the micellar interior.展开更多
Madhuca latifolia is an economically important medicinal and oil yielding plant of India having slow growth rate.As microbial application to the rhizosphere of host plant are beneficial for growth and development of p...Madhuca latifolia is an economically important medicinal and oil yielding plant of India having slow growth rate.As microbial application to the rhizosphere of host plant are beneficial for growth and development of plants,a comprehensive experimental study by using native microflora of Madhuca latifolia had been carried out in the nursery conditions.Isolation and identification of native rhizospheric soil revealed the occurrence of 17 different types of bacteria(gram negative and positive)and 30 numbers of fungi belonging to myceloid type,Aspergillus,Alternaria,Colletotrichum,Fusarium and Penicillium.Present study was confined to phosphate solubilizing microbes for which solubilization potential(solubilization index and solubilization efficiency)was evaluated.Inoculation experiments in pot culture with red laterite soil were set in two experimental categories(1)non-transplanted and(2)transplanted.Plants grown under both the conditions with and without microbial application were maintained up to 120 days and final data recorded for morphological,physiological growth and as soil parameters.The mineral solubilizing potential of native microbial strains has been expressed.Fungal inoculants were more effective than the bacterial inoculants as far as the growth and development of plants concerned.Among all,bacteria MLB-1,MLB-6,Aspergillus terreus and non-sporulating dematiaceous form of fungi were prominent in improving plant growth.This has also been confirmed the useful and beneficial impact of indigenous organism.The records made during the study is useful for development of bioinoculants for forest trees,nursery of quality planting material which will also helps in establishment at plantation site.展开更多
Phosphorus(P) limitation in the coming decades calls for the utilization of alternative fertilizers in agriculture. Struvite is a promising P source, but its potential role as a fertilizer is dependent on different ph...Phosphorus(P) limitation in the coming decades calls for the utilization of alternative fertilizers in agriculture. Struvite is a promising P source, but its potential role as a fertilizer is dependent on different physical, chemical, and biological properties, which are very heterogeneous in soil, complicating the prediction of the best soil conditions for its application. Here, we evaluated the solubility of struvite in soil, its redistribution into P fractions, and its potential abiotic and biotic drivers in 62 globally distributed soils with contrasting properties through an incubation assay. We found that after 40 d, about 35% of struvite P was redistributed into soil fractions more accessible to plants and microbes. Phosphorus redistribution from struvite was driven by a complex suite of soil physical, chemical, and microbial properties as well as environmental factors that varied across soils. Soil texture played a critical role in determining the redistribution of P in struvite-amended soils in soluble(H2O extraction), labile(NaHCO3 extraction), and moderately labile(NaOH extraction) fractions.In addition, the soil solution cation concentration was one of the most important drivers of available struvite-derived P fractions. The great importance of texture and cations in determining struvite-derived P fractions in soil was contrasted with the relatively minor role of pH. At the microbial level, the number of bacterial operational taxonomic units(OTUs) from the unfertilized soils that correlated with struvite-derived P fractions was higher than that of fungi. The number of OTUs that correlated with the struvite-derived soluble P fraction was dominated by fungi, whereas the number of OTUs that correlated with the struvite-derived labile P fraction was dominated by bacteria. Overall, this study provided a predictive framework for the potential use of struvite as a P fertilizer in contrasting soils.展开更多
Hydrophobic hydration,whereby water spontaneously structures around hydrophobic and amphiphilic molecules,plays a key role in the process of surfactant micelle formation and micellar oil solubilization.Using vibration...Hydrophobic hydration,whereby water spontaneously structures around hydrophobic and amphiphilic molecules,plays a key role in the process of surfactant micelle formation and micellar oil solubilization.Using vibrational Raman multivariate curve resolution spectroscopy,we characterized changes in the hydrophobic hydration occurring within nonionic alkylphenol ethoxylate surfactant Tergitol NP-12 micelles as a function of oil solubilization.We report trends in the changes of hydrophobic hydration depending on the chain length of the oil as well as the presence of a halogen atom in the oil chemical structure.Changes in hydrophobic hydration directly correlate to changes in the physical properties of the micellar solution,including cloud point and micelle hydrodynamic diameter.We compare hydrophobic hydration of Tergitol NP-12 to nonionic linear alkyl ethoxylate surfactant Makon TD-12 and ionic sodium dodecyl sulfate and observe similar trends;the molecular structure of the oil has the largest impact on the hydrophobic hydration.We believe these studies contribute to a fundamental understanding of the importance of hydrophobic hydration in surfactant and oil aggregates,especially as it relates to micellar oil solubilization,and provide insight into how the molecular solubilizate can impact micellar structure,size,and stability.展开更多
Biopolymer solubilization is considered to be the rate-limiting stage of anaerobic digestion of waste activated sludge(WAS). Oxidation processes have been proven to be effective in disrupting sludge flocs and causing ...Biopolymer solubilization is considered to be the rate-limiting stage of anaerobic digestion of waste activated sludge(WAS). Oxidation processes have been proven to be effective in disrupting sludge flocs and causing solubilization of the solid biopolymers. In this study,WAS was treated by NaNO2 or H2 O2 oxidation at p H of 2. The changes in extracellular polymeric substances properties and the speciation of heavy metals were investigated. The results revealed that both NaNO2 and H2 O2 treatments were effective in solubilizing organics in WAS, while the conversion of biopolymers in the two treatment processes was different. Free nitrous acid destroyed the gel network structure of EPS, and organic materials were released from the solid phase to the supernatant. Indigenous peroxidase catalyzed H2 O2 to produce hydroxyl radicals which caused significant solubilization of biopolymers, and the protein-like substances were further degraded into micro-molecule polypeptides or amino acids at high dosages of H2 O2. During the oxidation processes, Zn, Cd and Cu, with excellent mobility, tended to migrate to the supernatant, and thus were easy to remove through the liquid–solid separation process. Ni and As showed moderate migration ability, of which the residual fraction tended to transform into reducible and soluble fractions. With poor mobility, Cr and Pb mainly existed in the forms of residual and oxidizable fractions, which were difficult to dissolve and remove from WAS. Both NaNO2 and H2 O2 treatment resulted in the enhancement of sludge solubilization efficiency and heavy metal mobility in WAS, but different heavy metals showed distinct migration and transformation behaviors.展开更多
Phosphorus-solubilizing microbes play key roles in improving phosphorus availability and in alleviating phosphorus nutrient limitation in soils. However, we did not have a comprehensive understanding of the overall re...Phosphorus-solubilizing microbes play key roles in improving phosphorus availability and in alleviating phosphorus nutrient limitation in soils. However, we did not have a comprehensive understanding of the overall research progress and development trend of phosphorus solubilizing microorganisms. In this study, we obtain documents from the Web of Science (WOS) core collection between 2002 and 2022, and a comprehensive review of the progress of global research on soil phosphate solubilizing microorganisms was conducted by using the VOSviewer bibliometric analysis tool. The results showed an increasing trend in the number of published articles from 2002 to 2022. India, accounting for 28% of the total number of published articles, became the most productive country. However, Canada was the country with the highest average citation frequency of articles. Chinese Academy of Sciences (CAS) was the greatest contributor with the most publications. Among the published journals, Frontiers in Microbiology, Applied Soil Ecology and Plant and Soil were the top three core journals in this field. Based on the keyword analysis, the assessment of the mechanisms between phosphorus solubilizing microbes and the soil carbon cycles with the different management practices became the new research trend among the scientific communities. These findings would provide an important reference value for future in-depth research on soil phosphate solubilizing microorganisms.展开更多
The renaturation efficiency of recombinant prochymosin depends on not only the renaturation condi-tions but also the solubilization (denaturation) conditions. Compared with pH 8, solubilization of prochymosin-contain-...The renaturation efficiency of recombinant prochymosin depends on not only the renaturation condi-tions but also the solubilization (denaturation) conditions. Compared with pH 8, solubilization of prochymosin-contain-ing inclusion bodies at pH 11 (8 mol/L urea) results in onefold increase of renaturation efficiency ( ~ 40% vs. ~ 20 % ). Alkaline pH facilitates the solubilization of inclusion bodies via the breakage of intermolecular disulfide bonds. Moreover, alkaline pH renders prochymosin molecules to be in a more reduced and more unfolded state which undergoes refolding readily.展开更多
In this study,a dissipative particle dynamics mehtod was used to study the solubilization enhancing effect of platycodin towards 5 different drug components.Two factors were mainly considered,including the ,XlogP valu...In this study,a dissipative particle dynamics mehtod was used to study the solubilization enhancing effect of platycodin towards 5 different drug components.Two factors were mainly considered,including the ,XlogP value of drug components and the sugar chain length of platycodin.As a result,it was found that there was an optimal drug XlogP value for the solubilization enhancing effect of platycodin,and it was different between the drug's own XlogP value and the optimal drug XlogP value of platycodin that determines the solubilization enhancing effect.展开更多
This study assessed the influence of the composition of drug-free SNEDDS co-dosed with aqueous suspensions of carvedilol(CAR), cinnarizine(CIN) or R3040 on drug solubilization in a twocompartment in vitro lipolysis mo...This study assessed the influence of the composition of drug-free SNEDDS co-dosed with aqueous suspensions of carvedilol(CAR), cinnarizine(CIN) or R3040 on drug solubilization in a twocompartment in vitro lipolysis model. Correlation of drug log P or solubility in SNEDDS with drug solubilization during in vitro lipolysis in the presence of drug-free SNEDDS was assessed. SNEDDS with varying ratios of soybean oil:Maisine 35-1(1:1, w/w) and Kolliphor RH40, with ethanol at 10%(w/w) were used. SNEDDS were named F65, F55 and F20(numbers refer to the percentage of lipids) and aqueous suspensions without drug-free SNEDDS(F0) were also analyzed. While the ranking order of drug solubilization was F65? F55? F204F0 for CAR; F65? F554F204F0 for CIN and F65? F55? F204F0 for R3040-with higher CAR solubilization than for R3040 and CIN-the ranking of S_(eq)of CAR, CIN and R3040 in SNEDDS was F65 o F55o F20, F65? F554F20 and F654F554F20, respectively. Therefore, the composition of SNEDDS influenced the solubilization of CIN, but not CAR and R3040. Furthermore, high S_(eq) in SNEDDS did not reflect high drug solubilization. As CAR(log P 3.8) showed higher solubilization than CIN(log P 5.8) and R3040(log P 10.4), a correlation between drug log P and drug solubilization was observed.展开更多
Inactivation of pathogen indicators(i.e.,faecal coliforms,Salmonella spp.,faecal streptococcus,and helminth eggs)were investigated during alkaline pretreatment(pH=10 and 12)in this study.The performance of alkaline pr...Inactivation of pathogen indicators(i.e.,faecal coliforms,Salmonella spp.,faecal streptococcus,and helminth eggs)were investigated during alkaline pretreatment(pH=10 and 12)in this study.The performance of alkaline pretreatment on the inactivation pathogens,kinetic of pathogens inactivation and sludge solubilization was evaluated.Results of alkaline pretreatment showed that the complete inactivation periods of pathogens time were 1.5 d,1.5 d,2 d,2.5 d,3 d,3 d and 3 d for faecal sludge total solids(TS)of 1%,2%,4%,6%,8%,10%and 12%,respectively.The kinetics of pathogen inactivation can be predicted better by Weibull than the first-order model.Meanwhile,the relationship between alkaline pretreatment time and the TS content of the sludge agrees with the exponential equation(y=1.3543e10.002x,1%≤x≤8%)and logarithmic equation(y=3,8%≤x≤12%).Furthermore,alkaline pretreatment can improve sludge solubilization and has a more significant effect on protein solubilization than on soluble chemical oxygen demand(SCOD).展开更多
The solubility of beech wood cell wall in 8%lithium chloride/dimethyl sulfoxide(LiCl/DMSO)was investigated with an ethylenediamine(EDA)pretreatment without ball milling.EDA pretreatment of the wood cell wall was found...The solubility of beech wood cell wall in 8%lithium chloride/dimethyl sulfoxide(LiCl/DMSO)was investigated with an ethylenediamine(EDA)pretreatment without ball milling.EDA pretreatment of the wood cell wall was found to be an efficient method for the solubilization of the majority of the wood cell wall while avoiding the destructive effects of milling on the structure of the wood cell wall components.The yield of the final insoluble fraction was only approximately 31.6%based on the original Wiley wood sample after two EDA pretreatments and the dissolving processes.The solubility of lignocellulosic material in 8%LiCl/DMSO increased with decreasing lignin content after an EDA pretreatment.The yield of the insoluble fraction decreased from 62.9%to 9.2%with a decrease of lignin content from 28.0%to 14.1%.When the lignin content of lignocellulosic material was relatively low(approximately 10.5%),it could be dissolved in 8%LiCl/DMSO after an EDA pretreatment.The EDA pretreatment of wood meal had a much greater effect on polysaccharides than on the lignin in wood cell wall.展开更多
基金supported by the National Key Project for Basic Research and Development(G1999011803).
文摘Many microorganisms can dissolve the insoluble phosphates like apatite. However, the mechanisms are still not clear. This study was an attempt to investigate the mechanisms of rock phosphate solubilization by an Aspergillus 2TCiF2 and an Arthrobacter1TCRi7. The results indicated that the fungus produced a large amount of organic acids, mainly oxalic acid. The total quantity of the organic acids produced by the fungus was 550 times higher than that by the bacterium. Different organic acids had completely different capacities to solubilize the rock. Oxalic acid and citric acid had stronger capacity to dissolve the rock than malic acid, tartaric acid, lactic acid, acetic acid, malonic acid and succinic acid. The fungus solubilized the rock through excreting both proton and organic acids. The rock solubilization of the bacterium depended on only proton.
基金Natural Science Foundation of China for its financial support(grant number:U1762218)
文摘Reducing the oil-water interfacial tension(IFT)to ultra-low is believed the primary mechanism for surfactant-based enhanced oil recovery(EOR)process.However,field trials have shown that low concentration surfactant flooding can also improve oil recovery without ultra-low IFT.To clarify the mechanism behind,the currently-used surfactant,naphthenic arylsulfonate(NAS),was used to unravel its function during surfactant flooding from the horizon of micron-and nano-scale.The solubilization capacity of NAS micelle to petroleum fractions was evaluated through light absorbance strategy,smallangle neutron scattering,dynamic light scattering and transmission electron microscopy.It was found that micellar solubilization plays a significant role during the surfactant flooding.In-situ emulsification was visualized in microfluidics with three types of microchips,respectively.A series of displacement tests were carried out with NAS solution pumping into oil-saturated chip.The results show that in-situ emulsification improve oil recovery mainly through blocking and entrainment effects.Results from this work aid in understanding the interaction between surfactant solution and petroleum fractions at low surfactant concentration,which is helpful for design surfactant-based displacing system for EOR process.
文摘Plants need phosphorus for many physiological activities in a form of phosphate anions. Three different bacterial strains (Bacillus subtilis PH, Serratia marcescens PH1, and Serratia marcescens PH2), recently isolated from tomato plant rhizosphere, have high phosphate solubilization index (SI from 2.8 to 3.2) on Pikovskaya agar medium (which contains calcium phosphate). Moreover, phosphate release from calcium in Pikovskaya broth over 5 days is increasing with cell growth for the different isolates. The most efficient phosphate solubilization case is the mixed culture of the 3 strains (OD475 is almost 1). On the other hand, pH values decreased dramatically with time due to organic acids secretion and the maximum acidification level is recoded for Serratia marcescens PH2 (pH = 1.94). Interestingly, the isolates are resistance to important pesticides (oxamyl, thiophanate methyl, and captan) that are commonly used in the sampling area. This resistance is very favorable and increases the persistence of the phosphate solubilizing bacteria in contaminated soils. The isolates are therefore plant symbionts and growth promoting agents.
文摘The ability to solubilize insoluble inorganic pho- sphate compounds by Gluconacetobacter diazotrophicus was studied using different cul-ture approaches. Qualitative plate assays using tricalcium phosphate as the sole P-source showed that G. diazotrophicus produced solu-bilization only when aldoses were used as the C-source. Extracellular aldose oxidation via a pyrroloquinoline quinone-linked glucose dehy-drogenase (PQQ-GDH) is the main pathway for glucose metabolism in G. diazotrophicus. In batch cultures with 5 g l-1 of hydroxyapatite as the P-source and glucose as the C-source, more than 98% of insoluble P was solubilized. No solubilization was observed neither using glyc-erol nor culturing a PQQ-GDH mutant of G. di-azotrophicus. Solubilizaton was not affected by adding 100 mmol l-1 of MES buffer. Continuous cultures of G. diazotrophicus showed significant activities of PQQ-GDH either under C or P limi-tation. An intense acidification in the root envi-ronment of tomato and wheat seedlings inocu-lated with a G. diazotrophicus PAL5 was ob-served. Seedlings inoculated with a PQQ-GDH mutant strain of G. diazotrophicus showed no acidification. Our results suggest that G. di-azotrophicus is an excellent candidate to be used as biofertilizer because in addition to the already described plant growth-promoting abili-ties of this organism, it shows a significant mineral phosphate solubilization capacity.
文摘Rock phosphate (RP) is a low efficient P fertilizer when directly used in the soil. Phosphate-solubilizing microorganisms (PSMs) can solubilize RP in fermentation or soil condition. The effect of different concentration of lanthanum (La) on the solubilization of RP was investigated by two isolates of phosphate-solubilizing fungi (PSF) Aspergillus niger P39 and Penicillium oxalicum P66 in liquid culture. Experimental results show that relatively higher concentration of La in the culture solution inhibites fungal growth and delays RP solubilizing activity of two isolates. This inhibitory effect of La on RP solubilization varies with PSF (isolate P66 is more sensitive to La than P39 in this experiment). Comparing the pH value of culture media with soluble P content as affected by La application, only within individual isolate not different isolates the negatively significant relationship was observed.
基金the Deanship of Scientific Research(DSR),King Abdulaziz University,Jeddah,grant No.(G:255-2471440).
文摘2Hydroxy1,4napthoquinone(lawsone)natural redorange dye was extracted from fresh henna(Lawsonia inermis)leaves in an alkaline media.The lawsonesurfactant solubilization constants(KLS)were calculated for the first time by using cationic cetyltrimethylammonium bromide(CTAB)and anionic sodium dodecyl sulphate(SDS).The standard free energy,concentration of solubilized lawsone and number of lawsone molecules solubilized into micelles were calculated and discussed.Surface excess,minimum surface area per molecule,surface pressure,free energy(adsorption and aggregation)and equilibrium constants of different states were determined from tensiometry.Different metal ions(Ag^(+),Co^(2+),Cu^(2+),Ni^(2+),Fe^(3+),Zn^(2+)and Al^(3+)were used to determine the complex forming ability with lawsone.Out of these,Ag+ions have strong binding capacity with lawsone.The adsorption of lawsone on the surface of glass with silver ions in presence of CTAB was also observed at pH>9.0.The pseudofirst,secondorder kinetic equation,intraparticles diffusion and Elovich models were used to determine the kinetics of lawsone adsorption onto the surface of glass and a probable mechanism has been discussed.Lawsone adsorption followed secondorder kinetic equation(k_(2)=0.019 g·mg^(1)·min^(1)).
文摘Experimental data are presented on the enhanced solubilities of fluorene (FLR) resulting from solubilization in aqueous solutions of two conventional surfactants: cationic cetyltrimethylammonium bromide (CTAB) , anionic sodium dodecyl sulfate (SDS), nonioinic polyethylene glycol dodecyl ether (Brij35) and a cationic gemini bis (hexadecyldimethylammonium) pentane dibromide (G5). The critical micellar concentration of surfactants was determined by surface tension measurements and aqueous solubilities of fluorene compound in surfactant solutions were measured spectrophotometrically. Solubilization of PAH compound commenced at the surfactant critical micelle concentration and was proportional to the concentration of surfactant in micelle. The results of the mixed systems were analyzed with the help of regular solution theory, in which the deviation of CMCexp values for mixed surfactant systems from CMCideal was measured by evaluating the interaction parameter, βm. Negative values of βm were observed in all equimolar binary systems which show synergism in the mixed micelle. Attraction force between two oppositely charged head groups lead the strongest synergism effect between cationic gemini and anionic conventional surfactant. In addition to molar solubilization ratio (MSR) solubilization efficiency is also quantified in terms of micelle-water partition coefficient (Km).
文摘The dependence of solubilization properties on the alkyl chain length of alkyl glucosides (AG) in AG/isooctane/ n-butanol/water system was investigated. The stable Winsor II system consisting of a water-in-oil (w/o) microemulsion phase and an aqueous phase was formed in AG/isooctane/n-butanol/water system. The apparent critical micelle concentration of AG reverse micelles in organic phases was markedly dependent upon the alkyl chain length of AG. The limiting amount of solubilized water increased with an increase in the alkyl chain length of AG. The solubilization capacity of methyl orange (MO) was superior to that of methylene blue (MB), and the solubilization capacities of MO and MB tended to increase with increasing the alkyl chain length of AG. Reverse micelles of dodecyl glucoside (AG12) exhibited the significant solubilization capacities of cytochrome c and lysozyme, while ribonuclease A was not solubilized by AG12 reverse micelles.
文摘The partitioning of two non-steroidal anti-inflammatory drugs (NSAIDs), flurbiprofen and ketoprofen, into cationic cetyltrimethylammonium micelles was investigated using semi-equilibrium dialysis at 37℃ in phosphate buffered saline. The micellar-water solubilization equilibrium constants for both NSAIDs, in their deprotonated forms, were observed to decrease linearly with increasing mole fraction of drug in micelles. For flurbiprofen, the solubilization constant in the limit as mole fraction of drug in micelles approaches zero was found to be 11,200 (co = 1 M), while for ketoprofen the value was 1950 (co = 1 M). Using 1H-NMR and UV spectroscopic techniques, the locus of solubilization for ketoprofen was found to be towards the charged exterior of the micelles, in the Stern layer, whereas flurbiprofen was found to solubilize more in the micellar interior.
基金The financial assistance obtained from the Forest and Environment dept.,Govt.of Odisha(State plan 2016-17)is gratefully acknowledged.
文摘Madhuca latifolia is an economically important medicinal and oil yielding plant of India having slow growth rate.As microbial application to the rhizosphere of host plant are beneficial for growth and development of plants,a comprehensive experimental study by using native microflora of Madhuca latifolia had been carried out in the nursery conditions.Isolation and identification of native rhizospheric soil revealed the occurrence of 17 different types of bacteria(gram negative and positive)and 30 numbers of fungi belonging to myceloid type,Aspergillus,Alternaria,Colletotrichum,Fusarium and Penicillium.Present study was confined to phosphate solubilizing microbes for which solubilization potential(solubilization index and solubilization efficiency)was evaluated.Inoculation experiments in pot culture with red laterite soil were set in two experimental categories(1)non-transplanted and(2)transplanted.Plants grown under both the conditions with and without microbial application were maintained up to 120 days and final data recorded for morphological,physiological growth and as soil parameters.The mineral solubilizing potential of native microbial strains has been expressed.Fungal inoculants were more effective than the bacterial inoculants as far as the growth and development of plants concerned.Among all,bacteria MLB-1,MLB-6,Aspergillus terreus and non-sporulating dematiaceous form of fungi were prominent in improving plant growth.This has also been confirmed the useful and beneficial impact of indigenous organism.The records made during the study is useful for development of bioinoculants for forest trees,nursery of quality planting material which will also helps in establishment at plantation site.
基金the financial support by the Fundacion General CSIC, Spain (Programa ComFuturo)the project PID2020114942RB-I00 funded by MCIN/AEI//10.13039/5011000 11033+3 种基金supported by a project from the Spanish Ministry of Science and Innovation (No. PID2020-115813RA-I00)a project of the Fondo Europeo de Desarrollo Regional (FEDER)the Consejería de Transformación Económica, Industria, Conocimiento y Universidades of the Junta de Andalucía (FEDER Andalucía 2014-2020 Objetivo temático “01— Refuerzo de la investigación, el desarrollo tecnológico y la innovación”, ANDABIOMA, No. P20_00879)supported by a postdoctoral scholarship as part of the FCT-funded project “Soil Ecosystems in the XXI Century: Drivers, Conservation and Future Scenarios” (No. FCT-PTDC/BIACBI/2340/2020) led by IPVC, Portugal。
文摘Phosphorus(P) limitation in the coming decades calls for the utilization of alternative fertilizers in agriculture. Struvite is a promising P source, but its potential role as a fertilizer is dependent on different physical, chemical, and biological properties, which are very heterogeneous in soil, complicating the prediction of the best soil conditions for its application. Here, we evaluated the solubility of struvite in soil, its redistribution into P fractions, and its potential abiotic and biotic drivers in 62 globally distributed soils with contrasting properties through an incubation assay. We found that after 40 d, about 35% of struvite P was redistributed into soil fractions more accessible to plants and microbes. Phosphorus redistribution from struvite was driven by a complex suite of soil physical, chemical, and microbial properties as well as environmental factors that varied across soils. Soil texture played a critical role in determining the redistribution of P in struvite-amended soils in soluble(H2O extraction), labile(NaHCO3 extraction), and moderately labile(NaOH extraction) fractions.In addition, the soil solution cation concentration was one of the most important drivers of available struvite-derived P fractions. The great importance of texture and cations in determining struvite-derived P fractions in soil was contrasted with the relatively minor role of pH. At the microbial level, the number of bacterial operational taxonomic units(OTUs) from the unfertilized soils that correlated with struvite-derived P fractions was higher than that of fungi. The number of OTUs that correlated with the struvite-derived soluble P fraction was dominated by fungi, whereas the number of OTUs that correlated with the struvite-derived labile P fraction was dominated by bacteria. Overall, this study provided a predictive framework for the potential use of struvite as a P fertilizer in contrasting soils.
基金Army Research Office,Grant/Award Number:W911NF-18-1-0414David and Lucile Packard Foundation,Grant/Award Number:2019-69664National Science Foundation,Grant/Award Number:CHE-2004050。
文摘Hydrophobic hydration,whereby water spontaneously structures around hydrophobic and amphiphilic molecules,plays a key role in the process of surfactant micelle formation and micellar oil solubilization.Using vibrational Raman multivariate curve resolution spectroscopy,we characterized changes in the hydrophobic hydration occurring within nonionic alkylphenol ethoxylate surfactant Tergitol NP-12 micelles as a function of oil solubilization.We report trends in the changes of hydrophobic hydration depending on the chain length of the oil as well as the presence of a halogen atom in the oil chemical structure.Changes in hydrophobic hydration directly correlate to changes in the physical properties of the micellar solution,including cloud point and micelle hydrodynamic diameter.We compare hydrophobic hydration of Tergitol NP-12 to nonionic linear alkyl ethoxylate surfactant Makon TD-12 and ionic sodium dodecyl sulfate and observe similar trends;the molecular structure of the oil has the largest impact on the hydrophobic hydration.We believe these studies contribute to a fundamental understanding of the importance of hydrophobic hydration in surfactant and oil aggregates,especially as it relates to micellar oil solubilization,and provide insight into how the molecular solubilizate can impact micellar structure,size,and stability.
基金supported by the Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan) (Nos. CUGL170411, CUG160824)the National Nature Science Foundation of China (No. 51678546)
文摘Biopolymer solubilization is considered to be the rate-limiting stage of anaerobic digestion of waste activated sludge(WAS). Oxidation processes have been proven to be effective in disrupting sludge flocs and causing solubilization of the solid biopolymers. In this study,WAS was treated by NaNO2 or H2 O2 oxidation at p H of 2. The changes in extracellular polymeric substances properties and the speciation of heavy metals were investigated. The results revealed that both NaNO2 and H2 O2 treatments were effective in solubilizing organics in WAS, while the conversion of biopolymers in the two treatment processes was different. Free nitrous acid destroyed the gel network structure of EPS, and organic materials were released from the solid phase to the supernatant. Indigenous peroxidase catalyzed H2 O2 to produce hydroxyl radicals which caused significant solubilization of biopolymers, and the protein-like substances were further degraded into micro-molecule polypeptides or amino acids at high dosages of H2 O2. During the oxidation processes, Zn, Cd and Cu, with excellent mobility, tended to migrate to the supernatant, and thus were easy to remove through the liquid–solid separation process. Ni and As showed moderate migration ability, of which the residual fraction tended to transform into reducible and soluble fractions. With poor mobility, Cr and Pb mainly existed in the forms of residual and oxidizable fractions, which were difficult to dissolve and remove from WAS. Both NaNO2 and H2 O2 treatment resulted in the enhancement of sludge solubilization efficiency and heavy metal mobility in WAS, but different heavy metals showed distinct migration and transformation behaviors.
基金Scientific Research and Technology Development Program of PetroChina Company Limited(RISE2022KY08,2021DJ0806)Science and Technology Project of Hebei Education Department(BJK2022016).
文摘Phosphorus-solubilizing microbes play key roles in improving phosphorus availability and in alleviating phosphorus nutrient limitation in soils. However, we did not have a comprehensive understanding of the overall research progress and development trend of phosphorus solubilizing microorganisms. In this study, we obtain documents from the Web of Science (WOS) core collection between 2002 and 2022, and a comprehensive review of the progress of global research on soil phosphate solubilizing microorganisms was conducted by using the VOSviewer bibliometric analysis tool. The results showed an increasing trend in the number of published articles from 2002 to 2022. India, accounting for 28% of the total number of published articles, became the most productive country. However, Canada was the country with the highest average citation frequency of articles. Chinese Academy of Sciences (CAS) was the greatest contributor with the most publications. Among the published journals, Frontiers in Microbiology, Applied Soil Ecology and Plant and Soil were the top three core journals in this field. Based on the keyword analysis, the assessment of the mechanisms between phosphorus solubilizing microbes and the soil carbon cycles with the different management practices became the new research trend among the scientific communities. These findings would provide an important reference value for future in-depth research on soil phosphate solubilizing microorganisms.
基金Project supported by the National High Technology Programme.
文摘The renaturation efficiency of recombinant prochymosin depends on not only the renaturation condi-tions but also the solubilization (denaturation) conditions. Compared with pH 8, solubilization of prochymosin-contain-ing inclusion bodies at pH 11 (8 mol/L urea) results in onefold increase of renaturation efficiency ( ~ 40% vs. ~ 20 % ). Alkaline pH facilitates the solubilization of inclusion bodies via the breakage of intermolecular disulfide bonds. Moreover, alkaline pH renders prochymosin molecules to be in a more reduced and more unfolded state which undergoes refolding readily.
基金the Natural Science Foundation of Beijing,China(No.7162122).
文摘In this study,a dissipative particle dynamics mehtod was used to study the solubilization enhancing effect of platycodin towards 5 different drug components.Two factors were mainly considered,including the ,XlogP value of drug components and the sugar chain length of platycodin.As a result,it was found that there was an optimal drug XlogP value for the solubilization enhancing effect of platycodin,and it was different between the drug's own XlogP value and the optimal drug XlogP value of platycodin that determines the solubilization enhancing effect.
基金F.Hoffmann-La Roche Ltd.,Basel(1073861001)Switzerland for the financial supportthe CAPES Foundation,Ministry of Education of Brazil,Brasília(009416/2013-07)for the financial support of Ph.D student Scheyla Siqueira
文摘This study assessed the influence of the composition of drug-free SNEDDS co-dosed with aqueous suspensions of carvedilol(CAR), cinnarizine(CIN) or R3040 on drug solubilization in a twocompartment in vitro lipolysis model. Correlation of drug log P or solubility in SNEDDS with drug solubilization during in vitro lipolysis in the presence of drug-free SNEDDS was assessed. SNEDDS with varying ratios of soybean oil:Maisine 35-1(1:1, w/w) and Kolliphor RH40, with ethanol at 10%(w/w) were used. SNEDDS were named F65, F55 and F20(numbers refer to the percentage of lipids) and aqueous suspensions without drug-free SNEDDS(F0) were also analyzed. While the ranking order of drug solubilization was F65? F55? F204F0 for CAR; F65? F554F204F0 for CIN and F65? F55? F204F0 for R3040-with higher CAR solubilization than for R3040 and CIN-the ranking of S_(eq)of CAR, CIN and R3040 in SNEDDS was F65 o F55o F20, F65? F554F20 and F654F554F20, respectively. Therefore, the composition of SNEDDS influenced the solubilization of CIN, but not CAR and R3040. Furthermore, high S_(eq) in SNEDDS did not reflect high drug solubilization. As CAR(log P 3.8) showed higher solubilization than CIN(log P 5.8) and R3040(log P 10.4), a correlation between drug log P and drug solubilization was observed.
基金China Postdoctoral Science Foundation,Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants,and China's Ministry of Agriculture(GJFP201701203)China Agriculture Research System(CARS-36).
文摘Inactivation of pathogen indicators(i.e.,faecal coliforms,Salmonella spp.,faecal streptococcus,and helminth eggs)were investigated during alkaline pretreatment(pH=10 and 12)in this study.The performance of alkaline pretreatment on the inactivation pathogens,kinetic of pathogens inactivation and sludge solubilization was evaluated.Results of alkaline pretreatment showed that the complete inactivation periods of pathogens time were 1.5 d,1.5 d,2 d,2.5 d,3 d,3 d and 3 d for faecal sludge total solids(TS)of 1%,2%,4%,6%,8%,10%and 12%,respectively.The kinetics of pathogen inactivation can be predicted better by Weibull than the first-order model.Meanwhile,the relationship between alkaline pretreatment time and the TS content of the sludge agrees with the exponential equation(y=1.3543e10.002x,1%≤x≤8%)and logarithmic equation(y=3,8%≤x≤12%).Furthermore,alkaline pretreatment can improve sludge solubilization and has a more significant effect on protein solubilization than on soluble chemical oxygen demand(SCOD).
基金supported by the National Forestry Public Welfare Industry Research Project (201304609)the National Natural Science Foundation of China (31200444)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (12KJA220001).
文摘The solubility of beech wood cell wall in 8%lithium chloride/dimethyl sulfoxide(LiCl/DMSO)was investigated with an ethylenediamine(EDA)pretreatment without ball milling.EDA pretreatment of the wood cell wall was found to be an efficient method for the solubilization of the majority of the wood cell wall while avoiding the destructive effects of milling on the structure of the wood cell wall components.The yield of the final insoluble fraction was only approximately 31.6%based on the original Wiley wood sample after two EDA pretreatments and the dissolving processes.The solubility of lignocellulosic material in 8%LiCl/DMSO increased with decreasing lignin content after an EDA pretreatment.The yield of the insoluble fraction decreased from 62.9%to 9.2%with a decrease of lignin content from 28.0%to 14.1%.When the lignin content of lignocellulosic material was relatively low(approximately 10.5%),it could be dissolved in 8%LiCl/DMSO after an EDA pretreatment.The EDA pretreatment of wood meal had a much greater effect on polysaccharides than on the lignin in wood cell wall.
