A forest plantation, product of the reforestation of pine trees, represented a pool of biological resources for the implementation of a solid state fermentation process. The trees were identified as Pinus pseudostrobu...A forest plantation, product of the reforestation of pine trees, represented a pool of biological resources for the implementation of a solid state fermentation process. The trees were identified as Pinus pseudostrobus Lindl from which lignocellulosic material in the form of pine needles was collected. Soil fungi, responsible for plant litter decomposition, were cultured at laboratory conditions and tested for their ability to grow on cellulose and hemicellulose as the sole carbon sources. A fungal strain, belonging to the genus Penicillium, was selected for growing it on pine needles as the substrate in a solid state culture. After following the culture for six days, the newly isolated strain exhibited a much higher capacity for spore production and holocellulose degradation, compared to a purchased strain of Penicillium chrysogenum and two control conditions. This work marks the beginning of future studies focused on commercial applications and represents the first report of a biotechnological process based on pine needles and their degradation by an ascomycetes species belonging to the genus Penicillium.展开更多
Background:Rapeseed cake is a good source of protein for animal feed but its utilization is limited due to the presence of anti-nutritional substances,such as glucosinolates(GIs),phytic acid,tannins etc.In the present...Background:Rapeseed cake is a good source of protein for animal feed but its utilization is limited due to the presence of anti-nutritional substances,such as glucosinolates(GIs),phytic acid,tannins etc.In the present study,a solid state fermentation(SSF) using Aspergillus niger was carried out with the purpose of degrading glucosinolates and improving the nutritional quality of rapeseed cake(RSC).The effects of medium composition and incubation conditions on the GIs content in fermented rapeseed cake(FRSC) were investigated,and chemical composition and amino acid in vitro digestibility of RSC substrate fermented under optimal conditions were determined.Results:After 72 h of incubation at 34℃,a 76.89%decrease in GIs of RSC was obtained in solid medium containing 70%RSC,30%wheat bran at optimal moisture content 60%(w/w).Compared to unfermented RSC,trichloroacetic acid soluble protein(TCA-SP),crude protein and ether extract contents of the FRSC were increased(P< 0.05) 103.71,23.02 and 23.54%,respectively.As expected,the contents of NDF and phytic acid declined(P< 0.05) by 9.12 and 44.60%,respectively.Total amino acids(TAA) and essential amino acids(EAA) contents as well as AA in vitro digestibility of FRSC were improved significantly(P< 0.05).Moreover,the enzyme activity of endoglucanase,xylanase,acid protease and phytase were increased(P<0.05) during SSF.Conclusions:Our results indicate that the solid state fermentation offers an effective approach to improving the quality of proteins sources such as rapeseed cake.展开更多
Lignocellulosic substrates are a good carbon source and provide rich growth media for a variety of microorganisms which prodLuce industrially important enzymes. Cellulases are a group of hydrolytic enzymes such as fil...Lignocellulosic substrates are a good carbon source and provide rich growth media for a variety of microorganisms which prodLuce industrially important enzymes. Cellulases are a group of hydrolytic enzymes such as filter paperase (FPase), carboxymethyl cellulase(CMCase) andβ-glucosidase-responsible for release of sugars in the bioconversion of the lignocellulosic biomass into a variety of value-added products. This study examined cellulase production by a newly isolated Aspergillus unguis on individual lignocellulosic substrates in solid state fermentation (SSF). The maximum peak production of enzymes varied from one substrate to another, however,based on the next best solid support and local availability of groundnut fodder supported maximum enzyme yields compared with other solid supports used in this study.Groundnut fodder supported significant production of FPase (5.9 FPU/g of substrate), CMCase (1.1 U/g of substrate) andβ-glucosidase activity (6.5 U/g of substrate) in SSF. Considerable secretion of protein (27.0 mg/g of substrate) on groundnut fodder was recorded. Constant increment of protein content in groundnut fodder due to cultivation of A. unguis is an interesting observation and it has implications for the improvement of nutritive value of groundnut fodder for cattle.展开更多
The present study was conducted with an aim to scale up the production of iturin A using soybean curd residue (okara). Iturin A was produced by indigenous bacterial strain Bacillus subtilis RB14-CS through glass colum...The present study was conducted with an aim to scale up the production of iturin A using soybean curd residue (okara). Iturin A was produced by indigenous bacterial strain Bacillus subtilis RB14-CS through glass column reactor (GCR) under solid state fermentation (SSF) was characterized. The enhanced iturin A production was observed with respect to enhanced substrate bed height when SSF was conducted in Erlenmeyer flask. To check the effect of substrate bed height on iturin A production under SSF of okara, GCR was introduced. Substrate bed height of 15 cm was suitable for iturin A production which was about 2700 mg/kg wet substrate. The observed iturin A production by the aerobic bacteria Bacillus subtilis in nearly anaerobic condition in such high substrate bed for SSF is a wonderful finding for development of SSF system in future.展开更多
To optimize culture conditions for xylanase production by solid state fermentation (SSF) using Bacillus pumilus, with paddy husk as support, solid medium contained 200 g of paddy husk with 800 mL of liquid fermentatio...To optimize culture conditions for xylanase production by solid state fermentation (SSF) using Bacillus pumilus, with paddy husk as support, solid medium contained 200 g of paddy husk with 800 mL of liquid fermentation medium [xylan, 20.0 g/L; peptone, 2.0 g/L; yeast extract, 2.5 g/L; K2HPO4 , 2.5 g/L; KH2PO4 , 1.0 g/L; NaCl, 0.1 g/L; (NH4)2SO4 , 2.0 g/L, CaCl2 ·2H2O, 0.005 g/L; MgCl2 ·6H2O, 0.005 g/L; and FeCl 3 , 0.005 g/L] at pH 9.0 was applied. The highest xylanase activity (142.0 ±0.47 U/g DM] was obtained on the 6 th day at 30 ℃. The optimized paddy husk to liquid fermentation medium ratio was 2:9, and the optimized culture temperature was 40℃. When commercial Birchwood xylan was replaced with different concentrations of corncob, xylanase production was maximized (224.2 U/g DM) in the medium with 150 g/L corncob. Xylanase production was increased by sucrose, fructose and arabinose, whereas reduced by glucose, galactose, lactose and amylose. When organic nitrogen sources were replaced with locally available nitrogen sources such as groundnut powder or sesame seedcake powder or coconut seedcake powder or soy meal powder, the highest xylanase production (290.7 U/g DM) was obtained in the medium with soy meal powder and 16.0 g/L of soy meal powder was the optimum (326.5±0.34 U/g DM). Based on the optimization studies, B. pumilus produced 2.3 times higher xylanase activity. The medium cost was reduced from 2 458.3 to 178.3 SLR/kg and the total activity which could be obtained from 1 kg of the medium was increased from 48 624 to 220 253 Units.展开更多
[Objective] The aim was to optimize the appropriate solid state fermentation(SSF)conditions.[Method] The optimization of solid state fermentation using a mixture substrate of bean curd residue and the marc with Bacill...[Objective] The aim was to optimize the appropriate solid state fermentation(SSF)conditions.[Method] The optimization of solid state fermentation using a mixture substrate of bean curd residue and the marc with Bacillus natto was developed.[Result] The best fermentation condition optimized by the test of single factor and the orthogonal design respectively was mixing ratio of bean curd residue to marc 2∶1,substrate pH value 6,fermentation temperature 39 ℃,inoculum volume 10% and fermentation time 48 h.Under this optimized fermentation condition,the content of crude fiber in the substrate decreased from 107.8 mg/g before SSF to 56.2 mg/g after SSF,and the degeneration rate of crude fiber was 47.87%.[Conclusion] The bean curd residue in its palatability was enormously improved by SSF with Bacillus natto strain,which could be expected to be widely used as raw material of health foodstuff.展开更多
Solid-state fermentation (SSF) holds tremendous potentials for the production of industrially significant enzymes. The present study describes the production of lipase by a novel rumen bacterium, Pseudomonas sp. strai...Solid-state fermentation (SSF) holds tremendous potentials for the production of industrially significant enzymes. The present study describes the production of lipase by a novel rumen bacterium, Pseudomonas sp. strain BUP6 on agro-industrial residues. Pseudomonas sp. strain BUP6 showed higher lipase production when grown in Basal salt medium (BSM) supplemented with oil cakes. Initially, five different oil cakes (obtained after extracting oil from coconut, groundnut, cotton seed, gingelly or soybean) were screened to find out the most suitable substrate-cum-inducer for the production of lipase. Among them, groundnut cake supported the maximum production of lipase (107.44 U/gds). Box-Behnken Design (BBD), followed by response surface methodology (RSM) was employed to optimize the culture parameters for maximizing the production of lipase. Using the software Minitab 14, four different parameters like temperature, pH, moisture content and incubation time were selected for the statistical optimization, which resulted in 0.7 fold increase (i.e., 180.75 U/gds) in production of lipase under the optimum culture conditions (temperature 28°C, pH 5.9, moisture 33% and incubation 2 d). Thus, this study signifies the importance of SSF for the production of industrially-significant lipase using agro-industrial residues as solid support.展开更多
Xylanase is an important enzyme with potential application in the degradation of xylan component in the lignocellulosic biomass. There are very few reports on the production of cellulase free xylanases especially by y...Xylanase is an important enzyme with potential application in the degradation of xylan component in the lignocellulosic biomass. There are very few reports on the production of cellulase free xylanases especially by yeast strains which have great potential in paper and pulp industry in removing the hemicellulose from the treated or untreated pulp. In this study, P. hubeiensis NCIM 3574 isolated in our laboratory produced significant levels of extracellular cellulase free xylanase (2480 IU/g DSS) in solid state fermentation (SSF) using wheat bran and xylan. It also produced high levels of β-xylosidase (198 IU/g DSS) when grown in SSF using ground nut oil cake and xylan. These highest activities were obtained when fermented Koji was extracted with 1% NaCl supplemented with 0.5% of Triton X-100. These are the highest activities reported so far from yeast strains in the available literature. The crude xylanase preparation of P. hubeiensis produced xylooligosaccharides (XOS) without xylose proving its potential for XOS production with no further requirement of downstream processing. The XOS as prebiotic show beneficial effect on gut microflora such as Lactobacilli and Bifidobacteria which suppress the activity of pathogenic organisms. This xylanase also has a potential application as a bio-bleaching agent in paper and pulp industry.展开更多
This study reports lovastatin production by solid state fermentation using pomegranate seeds as a substrate. Six different fungal strains and several agro-industrial wastes were selected and screened. Various physico-...This study reports lovastatin production by solid state fermentation using pomegranate seeds as a substrate. Six different fungal strains and several agro-industrial wastes were selected and screened. Various physico-chemical parameters were optimized to improve lovastatin. Moreover, chemical mutation was systematically employed to enhance lovastatin yield on selected strains. Productivity of 3 ± 0.06 mg lovastatin/gm dfm was obtained prior to optimization. One factor a time followed by Response Surface Methodology (RSM) gave 4.2 ± 0.10 mg lovastatin/gm dfm yield in an optimized setup with pomegranate seed powder (5 gms), KH2PO4 (0.1% w/v), glucose (5% w/v), moisture (60% w/w), pH 5 in a 15 days fermentation cycle. The production was further increased to 6.5 ± 0.08 mg lovastatin/gm dfm through chemical mutation of the strain. This process is simple and reproducible for the production of lovastatin using pomegranate seed as an agro-industrial waste.展开更多
The high entropy alloys(HEAs)are the newly developed high-performance materials that have gained significant importance in defence,nuclear and aerospace sector due to their superior mechanical properties,heat resistan...The high entropy alloys(HEAs)are the newly developed high-performance materials that have gained significant importance in defence,nuclear and aerospace sector due to their superior mechanical properties,heat resistance,high temperature strength and corrosion resistance.These alloys are manufactured by the equal mixing or larger proportions of five or more alloying elements.HEAs exhibit superior mechanical performance compared to traditional engineering alloys because of the extensive alloying composition and higher entropy of mixing.Solid state welding(SSW)techniques such as friction stir welding(FSW),rotary friction welding(RFW),diffusion bonding(DB)and explosive welding(EW)have been efficiently deployed for improving the microstructural integrity and mechanical properties of welded HEA joints.The HEA interlayers revealed greater potential in supressing the formation of deleterious intermetallic phases and maximizing the mechanical properties of HEAs joints.The similar and dissimilar joining of HEAs has been manifested to be viable for HEA systems which further expands their industrial applications.Thus,the main objective of this review paper is to present a critical review of current state of research,challenges and opportunities and main directions in SSW of HEAs mainly CoCrFeNiMn and Al_xCoCrFeNi alloys.The state of the art of problems,progress and future outlook in SSW of HEAs are critically reviewed by considering the formation of phases,microstructural evolution and mechanical properties of HEAs joints.展开更多
[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temper...[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temperature,time,initial pH and inoculum amount on the antioxidant activity of natto solid fermentation.The optimum conditions of natto solid fermentation were determined and the antioxidant ac-tivity of natto extract was compared.[Results]The optimal fermentation conditions were as follows:temperature 32℃,initial pH 7.0,inocu-lation amount 8%,fermentation time 32 h.The hydroxyl radical scavenging rate of natto solid fermentation crude extract was the highest,which was 82.7%.The optimized nato fermentation extract showed stronger scavenging ability for-OH and O,:,and showed obvious dose-effect relationship.ICso was 3.63 and 4.24 mg/mL,respectively,and the scavenging efficiency was 1.3 and 1.9 times higher than that of the unoptimized fermentation extract,respectively.[Conclusions]Natto is rich in nattokinase and other functional factors,and its antioxidant ac-tivity can be improved by optimizing fermentation technology,so that natto products can be widely used,including cosmetic raw materials,nat-to skin care soap,health food and medicine,etc.,and have a broader development prospect.展开更多
Solid-state fermentation was carried out using mycelium powder of <em>Aspergillus niger</em> as substrate for the production of chitosanase of <em>Streptomyces</em>. Results of the experiments ...Solid-state fermentation was carried out using mycelium powder of <em>Aspergillus niger</em> as substrate for the production of chitosanase of <em>Streptomyces</em>. Results of the experiments indicated that the optimal medium consisted of wheat bran and mycelium powder of <em>Aspergillus niger</em> with initial moisture content of 60% - 70%. The enzyme activity reached 41.33 U per gram dry medium after cultured for 5 days at 28<span style="white-space:nowrap;">°</span>C - 30<span style="white-space:nowrap;">°</span>C and an initial pH 6.5. Chitosanase was detected on the second day of incubation and had maximal activity at 5 days and decreased gradually within a 1 month period. Solid-state fermentation is maybe an economic alternative in the production.展开更多
The performance sensitivity of the solid‐state lithium cells to the synergistic interactions of the charge‐transport and mechanical properties of the electrolyte is well acknowledged in the literature,but the quanti...The performance sensitivity of the solid‐state lithium cells to the synergistic interactions of the charge‐transport and mechanical properties of the electrolyte is well acknowledged in the literature,but the quantitative insights therein are very limited.Here,the charge‐transport and mechanical properties of a polymerized ionic‐liquid‐based solid electrolyte are reported.The transference number and diffusion coefficient of lithium in the concentrated solid electrolyte are measured as a function of concentration and stack pressure.The elastoplastic behavior of the electrolyte is quantified under compression,within a home‐made setup,to substantiate the impact of stack pressure on the stability of the Li/electrolyte interface in the symmetric lithium cells.The results spotlight the interaction between the concentration and thickness of the solid electrolyte and the stack pressure in determining the polarization and stability of the solid‐state lithium batteries during extended cycling.展开更多
The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation(SSF) with Lactobacillus brevis and Aspergillus oryzae,and to determine the effect of SSF on phytic...The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation(SSF) with Lactobacillus brevis and Aspergillus oryzae,and to determine the effect of SSF on phytic acid,crude protein,crude fat,and amino acid profile.Response surface methodology(RSM) with Box-Behnken design was used to optimize SSF.The optimal conditions derived from RSM for L.brevis fermentation were:pH=5.1;inoculum size=10%;duration=72 h;substrate to water ratio=1.5.The minimum content of trypsin inhibitors was 6.4 mg g-1 dry matter.The optimal conditions derived from RSM for A.oryzae fermentation were:substrate to water ratio= 0.81;inoculum size=4%;duration=120 h.The minimum content of trypsin inhibitors was 1.6 mg g-1 dry matter.Both L.brevis and A.oryzae decreased trypsin inhibitors dramatically(57.1 and 89.2% respectively).L.brevis fermentation did not affect phytic acid(0.4%) and crude fat(5.2%) considerably,whereas A.oryzae fermentation degraded phytic acid(34.8%) and crude fat(22.0%) contents to a certain extent.Crude protein content was increased after both fermentation(6.4 and 12.9% for L.brevis and A.oryzae respectively).Urease activity was reduced greatly(83.3 and 58.3% for L.brevis and A.oryzae respectively).In conclusion,SSF with A.oryzae and L.brevis reduced trypsin inhibitor content and modified major macronutrients in soybean meal.展开更多
Lovastatin production by Aspergillus terreus ATCC 20542 in solid-state fermentation (SSF) was studied. Various substrates were used to evaluate the ability of A. terreus to produce lovastatin. The results showed that ...Lovastatin production by Aspergillus terreus ATCC 20542 in solid-state fermentation (SSF) was studied. Various substrates were used to evaluate the ability of A. terreus to produce lovastatin. The results showed that either rice or wheat bran was suitable substrate for lovastatin production in SSF. The maximum yield of lovastatin (2.9 mg/g dry substrate) using rice as substrate was achieved after incubating for 11 d at the following optimized process parameters: 50%～60% initial moisture content,pH 5.5,incubation temperature 28 °C.展开更多
The work is intended to achieve optimum culture conditions of α-galactosidase production by a mutant strain Aspergillus foetidus ZU-G1 in solid-state fermentation (SSF). Certain fermentation parameters involving mois...The work is intended to achieve optimum culture conditions of α-galactosidase production by a mutant strain Aspergillus foetidus ZU-G1 in solid-state fermentation (SSF). Certain fermentation parameters involving moisture content, incubation temperature, cultivation period of seed, inoculum volume, initial pH value, layers of pledget, load size of medium and period of cultivation were investigated separately. The optimal cultivating conditions of α-galactosidase production in SSF were 60% initial moisture of medium, 28 °C incubation temperature, 18 h cultivation period of seed, 10% inoculum volume, 5.0～6.0 initial pH of medium, 6 layers of pledget and 10 g dry matter loadage. Under the optimized cultivation conditions, the maximum α-galactosidase production was 2 037.51 U/g dry matter near the 144th hour of fermentation.展开更多
The debittering effect of extracellular enzymes from Bacillus subtilis ACCC 01746 was studied using soybean meal as a substrate for solid-state fermentation(SSF).Results showed that B.subtilis produces proteases and c...The debittering effect of extracellular enzymes from Bacillus subtilis ACCC 01746 was studied using soybean meal as a substrate for solid-state fermentation(SSF).Results showed that B.subtilis produces proteases and carboxypeptidase in the early stage of SSF(0–8 h).Proteases are dominant and can hydrolyze the soybean protein into long-chain peptides with mild bitterness.Carboxypeptidase production is dominant at 8–16 h SSF,at which point soybean protein is further hydrolyzed and bitterness is enhanced.The strain then produces additional carboxypeptidase after 16 h,and bitterness is reduced.We compared the amino acid composition of the hydrolysates from soybean protein isolates to that of the fermented liquid of SSF.In the hydrolysates from soybean protein isolates that exhibit strong bitterness,62.81%of amino acids are hydrophobic and occur in the form of peptides.In the fermented liquid from soybean meal,16.22%of amino acids are hydrophobic and are mainly present in the form of free amino acids.The bitterness of fermented soybean hydrolysate is reduced from 5 to 0 when fermented for 24 h,suggesting that B.subtilis can effectively reduce bitterness,possibly due to the carboxypeptidase.Enzyme analysis shows that B.subtilis excretes carboxypeptidase during growth.The amino acids phenylalanine,alanine,tyrosine,and leucine at the C-terminal of the soybean bitter peptides in hydrolysates are cleaved in the presence of carboxypeptidase,resulting in complete debitterness.展开更多
文摘A forest plantation, product of the reforestation of pine trees, represented a pool of biological resources for the implementation of a solid state fermentation process. The trees were identified as Pinus pseudostrobus Lindl from which lignocellulosic material in the form of pine needles was collected. Soil fungi, responsible for plant litter decomposition, were cultured at laboratory conditions and tested for their ability to grow on cellulose and hemicellulose as the sole carbon sources. A fungal strain, belonging to the genus Penicillium, was selected for growing it on pine needles as the substrate in a solid state culture. After following the culture for six days, the newly isolated strain exhibited a much higher capacity for spore production and holocellulose degradation, compared to a purchased strain of Penicillium chrysogenum and two control conditions. This work marks the beginning of future studies focused on commercial applications and represents the first report of a biotechnological process based on pine needles and their degradation by an ascomycetes species belonging to the genus Penicillium.
基金granted by the Earmarked Fund for Modern Agro-industry Technology Research System of China(CARS-36)Feed Biotechnology Project of Sichuan Province of China with grant number 2010GZ0193
文摘Background:Rapeseed cake is a good source of protein for animal feed but its utilization is limited due to the presence of anti-nutritional substances,such as glucosinolates(GIs),phytic acid,tannins etc.In the present study,a solid state fermentation(SSF) using Aspergillus niger was carried out with the purpose of degrading glucosinolates and improving the nutritional quality of rapeseed cake(RSC).The effects of medium composition and incubation conditions on the GIs content in fermented rapeseed cake(FRSC) were investigated,and chemical composition and amino acid in vitro digestibility of RSC substrate fermented under optimal conditions were determined.Results:After 72 h of incubation at 34℃,a 76.89%decrease in GIs of RSC was obtained in solid medium containing 70%RSC,30%wheat bran at optimal moisture content 60%(w/w).Compared to unfermented RSC,trichloroacetic acid soluble protein(TCA-SP),crude protein and ether extract contents of the FRSC were increased(P< 0.05) 103.71,23.02 and 23.54%,respectively.As expected,the contents of NDF and phytic acid declined(P< 0.05) by 9.12 and 44.60%,respectively.Total amino acids(TAA) and essential amino acids(EAA) contents as well as AA in vitro digestibility of FRSC were improved significantly(P< 0.05).Moreover,the enzyme activity of endoglucanase,xylanase,acid protease and phytase were increased(P<0.05) during SSF.Conclusions:Our results indicate that the solid state fermentation offers an effective approach to improving the quality of proteins sources such as rapeseed cake.
文摘Lignocellulosic substrates are a good carbon source and provide rich growth media for a variety of microorganisms which prodLuce industrially important enzymes. Cellulases are a group of hydrolytic enzymes such as filter paperase (FPase), carboxymethyl cellulase(CMCase) andβ-glucosidase-responsible for release of sugars in the bioconversion of the lignocellulosic biomass into a variety of value-added products. This study examined cellulase production by a newly isolated Aspergillus unguis on individual lignocellulosic substrates in solid state fermentation (SSF). The maximum peak production of enzymes varied from one substrate to another, however,based on the next best solid support and local availability of groundnut fodder supported maximum enzyme yields compared with other solid supports used in this study.Groundnut fodder supported significant production of FPase (5.9 FPU/g of substrate), CMCase (1.1 U/g of substrate) andβ-glucosidase activity (6.5 U/g of substrate) in SSF. Considerable secretion of protein (27.0 mg/g of substrate) on groundnut fodder was recorded. Constant increment of protein content in groundnut fodder due to cultivation of A. unguis is an interesting observation and it has implications for the improvement of nutritive value of groundnut fodder for cattle.
基金supported by the Australian Research Council International Linkage Fellowship(No.LX0560210)the National Natural Science Foundation of China(No.30600082).
文摘The present study was conducted with an aim to scale up the production of iturin A using soybean curd residue (okara). Iturin A was produced by indigenous bacterial strain Bacillus subtilis RB14-CS through glass column reactor (GCR) under solid state fermentation (SSF) was characterized. The enhanced iturin A production was observed with respect to enhanced substrate bed height when SSF was conducted in Erlenmeyer flask. To check the effect of substrate bed height on iturin A production under SSF of okara, GCR was introduced. Substrate bed height of 15 cm was suitable for iturin A production which was about 2700 mg/kg wet substrate. The observed iturin A production by the aerobic bacteria Bacillus subtilis in nearly anaerobic condition in such high substrate bed for SSF is a wonderful finding for development of SSF system in future.
基金Sida/SAREC and International Science Programme in the Chemical Sciences (IPICS),Sweden, for the financial support
文摘To optimize culture conditions for xylanase production by solid state fermentation (SSF) using Bacillus pumilus, with paddy husk as support, solid medium contained 200 g of paddy husk with 800 mL of liquid fermentation medium [xylan, 20.0 g/L; peptone, 2.0 g/L; yeast extract, 2.5 g/L; K2HPO4 , 2.5 g/L; KH2PO4 , 1.0 g/L; NaCl, 0.1 g/L; (NH4)2SO4 , 2.0 g/L, CaCl2 ·2H2O, 0.005 g/L; MgCl2 ·6H2O, 0.005 g/L; and FeCl 3 , 0.005 g/L] at pH 9.0 was applied. The highest xylanase activity (142.0 ±0.47 U/g DM] was obtained on the 6 th day at 30 ℃. The optimized paddy husk to liquid fermentation medium ratio was 2:9, and the optimized culture temperature was 40℃. When commercial Birchwood xylan was replaced with different concentrations of corncob, xylanase production was maximized (224.2 U/g DM) in the medium with 150 g/L corncob. Xylanase production was increased by sucrose, fructose and arabinose, whereas reduced by glucose, galactose, lactose and amylose. When organic nitrogen sources were replaced with locally available nitrogen sources such as groundnut powder or sesame seedcake powder or coconut seedcake powder or soy meal powder, the highest xylanase production (290.7 U/g DM) was obtained in the medium with soy meal powder and 16.0 g/L of soy meal powder was the optimum (326.5±0.34 U/g DM). Based on the optimization studies, B. pumilus produced 2.3 times higher xylanase activity. The medium cost was reduced from 2 458.3 to 178.3 SLR/kg and the total activity which could be obtained from 1 kg of the medium was increased from 48 624 to 220 253 Units.
文摘[Objective] The aim was to optimize the appropriate solid state fermentation(SSF)conditions.[Method] The optimization of solid state fermentation using a mixture substrate of bean curd residue and the marc with Bacillus natto was developed.[Result] The best fermentation condition optimized by the test of single factor and the orthogonal design respectively was mixing ratio of bean curd residue to marc 2∶1,substrate pH value 6,fermentation temperature 39 ℃,inoculum volume 10% and fermentation time 48 h.Under this optimized fermentation condition,the content of crude fiber in the substrate decreased from 107.8 mg/g before SSF to 56.2 mg/g after SSF,and the degeneration rate of crude fiber was 47.87%.[Conclusion] The bean curd residue in its palatability was enormously improved by SSF with Bacillus natto strain,which could be expected to be widely used as raw material of health foodstuff.
文摘Solid-state fermentation (SSF) holds tremendous potentials for the production of industrially significant enzymes. The present study describes the production of lipase by a novel rumen bacterium, Pseudomonas sp. strain BUP6 on agro-industrial residues. Pseudomonas sp. strain BUP6 showed higher lipase production when grown in Basal salt medium (BSM) supplemented with oil cakes. Initially, five different oil cakes (obtained after extracting oil from coconut, groundnut, cotton seed, gingelly or soybean) were screened to find out the most suitable substrate-cum-inducer for the production of lipase. Among them, groundnut cake supported the maximum production of lipase (107.44 U/gds). Box-Behnken Design (BBD), followed by response surface methodology (RSM) was employed to optimize the culture parameters for maximizing the production of lipase. Using the software Minitab 14, four different parameters like temperature, pH, moisture content and incubation time were selected for the statistical optimization, which resulted in 0.7 fold increase (i.e., 180.75 U/gds) in production of lipase under the optimum culture conditions (temperature 28°C, pH 5.9, moisture 33% and incubation 2 d). Thus, this study signifies the importance of SSF for the production of industrially-significant lipase using agro-industrial residues as solid support.
文摘Xylanase is an important enzyme with potential application in the degradation of xylan component in the lignocellulosic biomass. There are very few reports on the production of cellulase free xylanases especially by yeast strains which have great potential in paper and pulp industry in removing the hemicellulose from the treated or untreated pulp. In this study, P. hubeiensis NCIM 3574 isolated in our laboratory produced significant levels of extracellular cellulase free xylanase (2480 IU/g DSS) in solid state fermentation (SSF) using wheat bran and xylan. It also produced high levels of β-xylosidase (198 IU/g DSS) when grown in SSF using ground nut oil cake and xylan. These highest activities were obtained when fermented Koji was extracted with 1% NaCl supplemented with 0.5% of Triton X-100. These are the highest activities reported so far from yeast strains in the available literature. The crude xylanase preparation of P. hubeiensis produced xylooligosaccharides (XOS) without xylose proving its potential for XOS production with no further requirement of downstream processing. The XOS as prebiotic show beneficial effect on gut microflora such as Lactobacilli and Bifidobacteria which suppress the activity of pathogenic organisms. This xylanase also has a potential application as a bio-bleaching agent in paper and pulp industry.
文摘This study reports lovastatin production by solid state fermentation using pomegranate seeds as a substrate. Six different fungal strains and several agro-industrial wastes were selected and screened. Various physico-chemical parameters were optimized to improve lovastatin. Moreover, chemical mutation was systematically employed to enhance lovastatin yield on selected strains. Productivity of 3 ± 0.06 mg lovastatin/gm dfm was obtained prior to optimization. One factor a time followed by Response Surface Methodology (RSM) gave 4.2 ± 0.10 mg lovastatin/gm dfm yield in an optimized setup with pomegranate seed powder (5 gms), KH2PO4 (0.1% w/v), glucose (5% w/v), moisture (60% w/w), pH 5 in a 15 days fermentation cycle. The production was further increased to 6.5 ± 0.08 mg lovastatin/gm dfm through chemical mutation of the strain. This process is simple and reproducible for the production of lovastatin using pomegranate seed as an agro-industrial waste.
基金financially supported by Ministry of Science and Higher Education of the Russian Federation(Grant No.FENU-2023-0013)。
文摘The high entropy alloys(HEAs)are the newly developed high-performance materials that have gained significant importance in defence,nuclear and aerospace sector due to their superior mechanical properties,heat resistance,high temperature strength and corrosion resistance.These alloys are manufactured by the equal mixing or larger proportions of five or more alloying elements.HEAs exhibit superior mechanical performance compared to traditional engineering alloys because of the extensive alloying composition and higher entropy of mixing.Solid state welding(SSW)techniques such as friction stir welding(FSW),rotary friction welding(RFW),diffusion bonding(DB)and explosive welding(EW)have been efficiently deployed for improving the microstructural integrity and mechanical properties of welded HEA joints.The HEA interlayers revealed greater potential in supressing the formation of deleterious intermetallic phases and maximizing the mechanical properties of HEAs joints.The similar and dissimilar joining of HEAs has been manifested to be viable for HEA systems which further expands their industrial applications.Thus,the main objective of this review paper is to present a critical review of current state of research,challenges and opportunities and main directions in SSW of HEAs mainly CoCrFeNiMn and Al_xCoCrFeNi alloys.The state of the art of problems,progress and future outlook in SSW of HEAs are critically reviewed by considering the formation of phases,microstructural evolution and mechanical properties of HEAs joints.
基金Supported by 2023 Zhanjiang Non-funded Science and Technology Research Plan(2023B01023)2022 University-level Education and Teaching Reform Project of Lingnan Normal University(LingShiJiaoWu2022154).Junxia SONG,bachelor degree,experimenter,research fields:physical geography.
文摘[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temperature,time,initial pH and inoculum amount on the antioxidant activity of natto solid fermentation.The optimum conditions of natto solid fermentation were determined and the antioxidant ac-tivity of natto extract was compared.[Results]The optimal fermentation conditions were as follows:temperature 32℃,initial pH 7.0,inocu-lation amount 8%,fermentation time 32 h.The hydroxyl radical scavenging rate of natto solid fermentation crude extract was the highest,which was 82.7%.The optimized nato fermentation extract showed stronger scavenging ability for-OH and O,:,and showed obvious dose-effect relationship.ICso was 3.63 and 4.24 mg/mL,respectively,and the scavenging efficiency was 1.3 and 1.9 times higher than that of the unoptimized fermentation extract,respectively.[Conclusions]Natto is rich in nattokinase and other functional factors,and its antioxidant ac-tivity can be improved by optimizing fermentation technology,so that natto products can be widely used,including cosmetic raw materials,nat-to skin care soap,health food and medicine,etc.,and have a broader development prospect.
文摘Solid-state fermentation was carried out using mycelium powder of <em>Aspergillus niger</em> as substrate for the production of chitosanase of <em>Streptomyces</em>. Results of the experiments indicated that the optimal medium consisted of wheat bran and mycelium powder of <em>Aspergillus niger</em> with initial moisture content of 60% - 70%. The enzyme activity reached 41.33 U per gram dry medium after cultured for 5 days at 28<span style="white-space:nowrap;">°</span>C - 30<span style="white-space:nowrap;">°</span>C and an initial pH 6.5. Chitosanase was detected on the second day of incubation and had maximal activity at 5 days and decreased gradually within a 1 month period. Solid-state fermentation is maybe an economic alternative in the production.
基金H2020 LEIT Advanced Materials,Grant/Award Number:875557。
文摘The performance sensitivity of the solid‐state lithium cells to the synergistic interactions of the charge‐transport and mechanical properties of the electrolyte is well acknowledged in the literature,but the quantitative insights therein are very limited.Here,the charge‐transport and mechanical properties of a polymerized ionic‐liquid‐based solid electrolyte are reported.The transference number and diffusion coefficient of lithium in the concentrated solid electrolyte are measured as a function of concentration and stack pressure.The elastoplastic behavior of the electrolyte is quantified under compression,within a home‐made setup,to substantiate the impact of stack pressure on the stability of the Li/electrolyte interface in the symmetric lithium cells.The results spotlight the interaction between the concentration and thickness of the solid electrolyte and the stack pressure in determining the polarization and stability of the solid‐state lithium batteries during extended cycling.
基金supported by a research project of the Science and Technology Key Group in Zhejiang Provincethe research projects from the Science and Technology Department of Zhejiang Province,China (2009C12068)
文摘The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation(SSF) with Lactobacillus brevis and Aspergillus oryzae,and to determine the effect of SSF on phytic acid,crude protein,crude fat,and amino acid profile.Response surface methodology(RSM) with Box-Behnken design was used to optimize SSF.The optimal conditions derived from RSM for L.brevis fermentation were:pH=5.1;inoculum size=10%;duration=72 h;substrate to water ratio=1.5.The minimum content of trypsin inhibitors was 6.4 mg g-1 dry matter.The optimal conditions derived from RSM for A.oryzae fermentation were:substrate to water ratio= 0.81;inoculum size=4%;duration=120 h.The minimum content of trypsin inhibitors was 1.6 mg g-1 dry matter.Both L.brevis and A.oryzae decreased trypsin inhibitors dramatically(57.1 and 89.2% respectively).L.brevis fermentation did not affect phytic acid(0.4%) and crude fat(5.2%) considerably,whereas A.oryzae fermentation degraded phytic acid(34.8%) and crude fat(22.0%) contents to a certain extent.Crude protein content was increased after both fermentation(6.4 and 12.9% for L.brevis and A.oryzae respectively).Urease activity was reduced greatly(83.3 and 58.3% for L.brevis and A.oryzae respectively).In conclusion,SSF with A.oryzae and L.brevis reduced trypsin inhibitor content and modified major macronutrients in soybean meal.
基金Project (No. 20061475) supported by Education Department of Zhejiang Province, China
文摘Lovastatin production by Aspergillus terreus ATCC 20542 in solid-state fermentation (SSF) was studied. Various substrates were used to evaluate the ability of A. terreus to produce lovastatin. The results showed that either rice or wheat bran was suitable substrate for lovastatin production in SSF. The maximum yield of lovastatin (2.9 mg/g dry substrate) using rice as substrate was achieved after incubating for 11 d at the following optimized process parameters: 50%～60% initial moisture content,pH 5.5,incubation temperature 28 °C.
文摘The work is intended to achieve optimum culture conditions of α-galactosidase production by a mutant strain Aspergillus foetidus ZU-G1 in solid-state fermentation (SSF). Certain fermentation parameters involving moisture content, incubation temperature, cultivation period of seed, inoculum volume, initial pH value, layers of pledget, load size of medium and period of cultivation were investigated separately. The optimal cultivating conditions of α-galactosidase production in SSF were 60% initial moisture of medium, 28 °C incubation temperature, 18 h cultivation period of seed, 10% inoculum volume, 5.0～6.0 initial pH of medium, 6 layers of pledget and 10 g dry matter loadage. Under the optimized cultivation conditions, the maximum α-galactosidase production was 2 037.51 U/g dry matter near the 144th hour of fermentation.
基金supported by Grain&Corn Engineering Technology Research Center,State Administration of Grain(GA2017004)Science and Technology Research Project of Henan(172102110205)Henan University of Technology:Integration of Science and Education(30)
文摘The debittering effect of extracellular enzymes from Bacillus subtilis ACCC 01746 was studied using soybean meal as a substrate for solid-state fermentation(SSF).Results showed that B.subtilis produces proteases and carboxypeptidase in the early stage of SSF(0–8 h).Proteases are dominant and can hydrolyze the soybean protein into long-chain peptides with mild bitterness.Carboxypeptidase production is dominant at 8–16 h SSF,at which point soybean protein is further hydrolyzed and bitterness is enhanced.The strain then produces additional carboxypeptidase after 16 h,and bitterness is reduced.We compared the amino acid composition of the hydrolysates from soybean protein isolates to that of the fermented liquid of SSF.In the hydrolysates from soybean protein isolates that exhibit strong bitterness,62.81%of amino acids are hydrophobic and occur in the form of peptides.In the fermented liquid from soybean meal,16.22%of amino acids are hydrophobic and are mainly present in the form of free amino acids.The bitterness of fermented soybean hydrolysate is reduced from 5 to 0 when fermented for 24 h,suggesting that B.subtilis can effectively reduce bitterness,possibly due to the carboxypeptidase.Enzyme analysis shows that B.subtilis excretes carboxypeptidase during growth.The amino acids phenylalanine,alanine,tyrosine,and leucine at the C-terminal of the soybean bitter peptides in hydrolysates are cleaved in the presence of carboxypeptidase,resulting in complete debitterness.
