The objective of this work was to investigate the effect of six individual strains of fungi on the reduction of gossypol levels and nutritional value during solid substrate fen＇aentation of cottonseed meal （CSM）. S...The objective of this work was to investigate the effect of six individual strains of fungi on the reduction of gossypol levels and nutritional value during solid substrate fen＇aentation of cottonseed meal （CSM）. Six groups of disinfected CSM substrate were incubated for 48 h after inoculation with either of the fungi C. capsuligena ZD- 1, C. tropicalis ZD-3, S. cerevisae ZD-5, A. terricola ZD-6, A. oryzae ZD-7, or A. niger ZD-8. One not inoculated group （substrate） was used as a control. Levels of initial and final free gossypol （FG）, crude protein （CP）, amino acids （AA） and in vitro digestibility were assayed. The experiment was done in triplicate. The experimental results indicated that microbial fermentation could greatly decrease （P〈0.05） FG levels in CSM. The detoxification efficiency differed between the species of microorganisms applied. From the perspective of reducing CSM potential toxicity, C. tropicalis ZD-3 was most successful followed by S. cerevisae ZD-5 and A. niger ZD-8. They could reduce FG levels of CSM to 29.8, 63.07 and 81.50 mg/kg based on DM （dry matter）, respectively, and their detoxification rates were 94.57%, 88.51% and 85.16%, respectively. If crude protein, amino acids content and their in vitro digestibility were also taken into account, Aniger ZD-8 may be the best choice. The CP content of CSM substrate fermented by C. tropicalis ZD-3 and A. niger ZD-8 were improved by 10.76% and 22.24%; the TAA （total amino acids） contents were increased by 7.06% and 11.46%, and the EAA （essential amino acids） were raised by 7.77% and 12.64%, respectively. Especially, the levels of methionine, lysine and threonine were improved greatly （P〈0.05）. The in vitro CP digestibility of CSM fermented by C. tropicalis ZD-3 and A. niger ZD-8 was improved by 13.42% and 18.22%, the TAA were increased by 17.75% and 22.88%, and the EAA by 16.61% and 21.01%, respectively. In addition, the in vitro digestibility of methionine, lysine and threonine was also improved greatly （P〈0.05）.展开更多
In order to investigate the effects of processing pH stimulation on bioleaching of chalcopyrite by moderate thermophiles,copper leaching rates and the dynamics of microbial community structures of free and attached ce...In order to investigate the effects of processing pH stimulation on bioleaching of chalcopyrite by moderate thermophiles,copper leaching rates and the dynamics of microbial community structures of free and attached cells were monitored. The results indicated that when the processing pH values were respectively adjusted to 1.0 and 3.0 on day 14, both free and attached cells experienced an adaptive phase. Meanwhile, the copper leaching rates were 86.9% and 64.0%,respectively, as opposed to a copper leaching rate of 87.5% in the control group without pH stimulation. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis suggested that pH stimulation imposed less impact on the attached organisms than on the free cells, indicating that the attached cells were more resistant to processing pH stimulation than the free cells. Furthermore, adjusting processing pH to 3.0 significantly disrupted both free and attached microbial communities, and the bioleaching system could not recover to the normal status as the control group.展开更多
The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM)...The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM).The bacterial communities of free,attached,weakly-attached,and strongly-attached microbes in the later bioleaching stage were investigated.In AM group,the addition of lump sulphide ore resulted in the low leachate pH,high ferric iron concentration,and rapid microbial adsorption,which obtained the maximum copper extraction(60.1%)compared with LM(54.6%)and PM(43.9%)groups.The relative abundance of dominant genera and microbial communities of different microbiota underwent changes in three heap construction methods.The alpha-diversity indexes of attached,weakly-attached,and strongly-attached microbes were different,while no significant change was observed in free bacteria.The variation of whole bacterial community was significantly associated with solution pH,total iron,and ferric iron concentrations.Pearson correlation analysis and partial least square path model both indicated that attached bacteria made larger contribution to the copper extraction of tailings.展开更多
[Objective] This study aims to reduce the free gossypol(FG) and improve utilization rate of cottonseed meal(CSM) by solid state fermentation(SSF). [Method]Bacillus subtilis GJ00141 and Saccharomyces cerevisiae GJ00079...[Objective] This study aims to reduce the free gossypol(FG) and improve utilization rate of cottonseed meal(CSM) by solid state fermentation(SSF). [Method]Bacillus subtilis GJ00141 and Saccharomyces cerevisiae GJ00079 were applied for the SSF and the optimal carbon source, nitrogen source, inorganic salt, moisture content, inoculum level, fermentation temperature, and fermentation time were investigated. The detoxifying effects of different products of GJ00141 were examined with gossypol as substrate. A total of 90 one-day-old broilers were randomized into group A [control, basal diet with 36% soybean meal(SM)], group B(basal diet with 18% SM and 18% CSM), and group C [basal diet with 18% SM and 18% fermented CSM(FCSM)] and thereby the influence of FCSM on the growth of broilers was explored. [Results] The maximum reduction rate(59%) of FG was achieved under the following fermentation conditions: solid medium composed of 96% CSM, 1%glucose, 1% ammonium sulfate, and 2% corn grits, 45% moisture content, 20%inoculum, fermentation at 30 °C for 60 h. Both the viable and inactivated cells of GJ00141 can reduce the content of gossypol, but the reduction rates were only about 20% after 72 h of incubation. Cellular contents and supernatant demonstrated strong detoxifying activity, which achieved the reduction rates of about 95% after 48 h, and the removal was free from the influence of proteinase K, heat, or EDTA. In the 42 d feeding experiment on broilers, the ratios of feed to gain were insignificantly different between the group C and group A. [Conclusion] This method achieved high rate of removing FG in CSM. The reason was the likelihood that the stable compounds in the cellular contents and supernatant of GJ00141 adsorb or bind to FG. Broilers grew well with the FCSM. Thus, it was an efficient detoxifying method for CSM.展开更多
Organic biomass is an attractive feedstock for second generation alcohol production. Wild-type strains of the genus Candida showed capabilities different to produce alcohol fermenting a carbohydrates mixture （synthet...Organic biomass is an attractive feedstock for second generation alcohol production. Wild-type strains of the genus Candida showed capabilities different to produce alcohol fermenting a carbohydrates mixture （synthetic medium）, individually and in co-culture. Therefore, the main objective of this work was to evaluate the capability of Candida wild-type strains isolated from termite gut and rumen liquid, to ferment the most commonly carbohydrates presented in citrus residues, individually and in co-culture to alcohol production. C Tropicalis （LR4） presented higher percentage of carbohydrate consumption （74.20% ± 4.60%）, alcohol production （44.53 ± 0.01 gLl） and maximal alcohol productivity （6.40 ± 0.01 gL-l day） than C Glabrata （T1）. Co-culture schemas, CC1 （LR4： 60%; TI： 40%） and CC3 （first LR4 alone and 2 days later T1） presented the highest alcohol production （45.20 ± 1.30 gL-1 and 46.80 ± 2.60 gL-1, respectively）. Maximal alcohol productivity was obtained with CC2 （LR4： 80%; TI： 20%） and CC3 schemas, 7.70 ± 0.29 gL-1 day and 7.80 ± 0.44 gL-l day, respectively. The results suggest the usefulness of these wild-type strains in co-culture as an alternative to alcohol production from carbohydrates mixtures at concentrations commonly found in citrus waste.展开更多
[Objective] This study to aimed to investigate the effects of Cu stress on root exudates and microbial activities in rhizosphere of grafted and ungrafted cucum-ber seedlings, and therefore to elucidate the microbial m...[Objective] This study to aimed to investigate the effects of Cu stress on root exudates and microbial activities in rhizosphere of grafted and ungrafted cucum-ber seedlings, and therefore to elucidate the microbial mechanism of grafting for in-creasing cucumber plants tolerance to Cu stress [Method] Four treatments： （1） un-grafted seedlings ＋ test soil （U0）; （2） ungrafted seedlings ＋ test soil ＋ CuSO4·5H2O （U1）; （3） grafted seedlings ＋ test soil （G0）; （4） grafted seedlings ＋ test soil ＋ Cu-SO4·5H2O （G1） were set in the pot culture experiment. The contents of free amino acids, organic acids, phenolic acid and sugars, microbial population and enzyme ac-tivity in the four treatment were measured, respectively. [Result] The secretion of amino acids and organic acids were increased under Cu stress. The amino acids secretions of grafted seedlings roots were obviously higher than ungrafted seedlings except for Phe and Val. At the same time, the secretion of oxalic acid, malic acid, acetic acid, citric acid, cinnamic acid, ρ-hydroxybenzoic acid and benzoic acid of grafted seedlings were significantly higher than ungrafted seedlings as wel . There-fore, more Cu2＋ were restricted in soil by chelating, complexing and precipitation with root exudates, and its toxicity was decreased. The soil microbial biomass C and N in grafted cucumber rhizosphere were significantly higher than those in ungrafted cu-cumber rhizosphere, whereas basal respiration and metabolic quotient were signifi-cantly lower. Under Cu stress, the numbers of actinomyces and nitrogen fixing bac-teria decreased and the number of fungi increased significantly, whereas there was no significant difference in amounts of bacteria. The numbers of bacteria, actino-myces, and nitrogen fixing bacteria in grafted cucumber rhizosphere were significant-ly higher than those in ungrafted cucumber rhizosphere, but the number of fungi was opposite. The activities of soil urease, phosphatase, sucrase and catalase in grafted cucumber rhizosphere were significantly higher than those in ungrafted cu-cumber rhizosphere. [Conclusion] These indicated that the soil microbial environment and soil enzymes activities were improved by grafting under Cu stress, and as a re-sult, the adaptability of cucumber to Cu stress was improved.展开更多
基金Project (No. 30471255) supported by the National Natural ScienceFoundation of China
文摘The objective of this work was to investigate the effect of six individual strains of fungi on the reduction of gossypol levels and nutritional value during solid substrate fen＇aentation of cottonseed meal （CSM）. Six groups of disinfected CSM substrate were incubated for 48 h after inoculation with either of the fungi C. capsuligena ZD- 1, C. tropicalis ZD-3, S. cerevisae ZD-5, A. terricola ZD-6, A. oryzae ZD-7, or A. niger ZD-8. One not inoculated group （substrate） was used as a control. Levels of initial and final free gossypol （FG）, crude protein （CP）, amino acids （AA） and in vitro digestibility were assayed. The experiment was done in triplicate. The experimental results indicated that microbial fermentation could greatly decrease （P〈0.05） FG levels in CSM. The detoxification efficiency differed between the species of microorganisms applied. From the perspective of reducing CSM potential toxicity, C. tropicalis ZD-3 was most successful followed by S. cerevisae ZD-5 and A. niger ZD-8. They could reduce FG levels of CSM to 29.8, 63.07 and 81.50 mg/kg based on DM （dry matter）, respectively, and their detoxification rates were 94.57%, 88.51% and 85.16%, respectively. If crude protein, amino acids content and their in vitro digestibility were also taken into account, Aniger ZD-8 may be the best choice. The CP content of CSM substrate fermented by C. tropicalis ZD-3 and A. niger ZD-8 were improved by 10.76% and 22.24%; the TAA （total amino acids） contents were increased by 7.06% and 11.46%, and the EAA （essential amino acids） were raised by 7.77% and 12.64%, respectively. Especially, the levels of methionine, lysine and threonine were improved greatly （P〈0.05）. The in vitro CP digestibility of CSM fermented by C. tropicalis ZD-3 and A. niger ZD-8 was improved by 13.42% and 18.22%, the TAA were increased by 17.75% and 22.88%, and the EAA by 16.61% and 21.01%, respectively. In addition, the in vitro digestibility of methionine, lysine and threonine was also improved greatly （P〈0.05）.
基金Project(31200382)supported by the National Natural Science Foundation of ChinaProject(2013FJ4068)supported by the Planned Science and Technology Project of Hunan Province,ChinaProject supported by Australia CSIRO OCE Science Leader Grant
文摘In order to investigate the effects of processing pH stimulation on bioleaching of chalcopyrite by moderate thermophiles,copper leaching rates and the dynamics of microbial community structures of free and attached cells were monitored. The results indicated that when the processing pH values were respectively adjusted to 1.0 and 3.0 on day 14, both free and attached cells experienced an adaptive phase. Meanwhile, the copper leaching rates were 86.9% and 64.0%,respectively, as opposed to a copper leaching rate of 87.5% in the control group without pH stimulation. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis suggested that pH stimulation imposed less impact on the attached organisms than on the free cells, indicating that the attached cells were more resistant to processing pH stimulation than the free cells. Furthermore, adjusting processing pH to 3.0 significantly disrupted both free and attached microbial communities, and the bioleaching system could not recover to the normal status as the control group.
基金financial supports from the National Key R&D Program of China(No.2018YFC1801804)the Shandong Provincial Natural Science Foundation,China(Nos.ZR2020QD120 and ZR2018LD001)Project of Introducing and Cultivating Young Talent in the Universities of Shandong Province,China(No.QC2019YY144)。
文摘The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM).The bacterial communities of free,attached,weakly-attached,and strongly-attached microbes in the later bioleaching stage were investigated.In AM group,the addition of lump sulphide ore resulted in the low leachate pH,high ferric iron concentration,and rapid microbial adsorption,which obtained the maximum copper extraction(60.1%)compared with LM(54.6%)and PM(43.9%)groups.The relative abundance of dominant genera and microbial communities of different microbiota underwent changes in three heap construction methods.The alpha-diversity indexes of attached,weakly-attached,and strongly-attached microbes were different,while no significant change was observed in free bacteria.The variation of whole bacterial community was significantly associated with solution pH,total iron,and ferric iron concentrations.Pearson correlation analysis and partial least square path model both indicated that attached bacteria made larger contribution to the copper extraction of tailings.
基金Supported by the Academic Research Projects of Beijing Union University (ZK30202104, ZK20202101)。
文摘[Objective] This study aims to reduce the free gossypol(FG) and improve utilization rate of cottonseed meal(CSM) by solid state fermentation(SSF). [Method]Bacillus subtilis GJ00141 and Saccharomyces cerevisiae GJ00079 were applied for the SSF and the optimal carbon source, nitrogen source, inorganic salt, moisture content, inoculum level, fermentation temperature, and fermentation time were investigated. The detoxifying effects of different products of GJ00141 were examined with gossypol as substrate. A total of 90 one-day-old broilers were randomized into group A [control, basal diet with 36% soybean meal(SM)], group B(basal diet with 18% SM and 18% CSM), and group C [basal diet with 18% SM and 18% fermented CSM(FCSM)] and thereby the influence of FCSM on the growth of broilers was explored. [Results] The maximum reduction rate(59%) of FG was achieved under the following fermentation conditions: solid medium composed of 96% CSM, 1%glucose, 1% ammonium sulfate, and 2% corn grits, 45% moisture content, 20%inoculum, fermentation at 30 °C for 60 h. Both the viable and inactivated cells of GJ00141 can reduce the content of gossypol, but the reduction rates were only about 20% after 72 h of incubation. Cellular contents and supernatant demonstrated strong detoxifying activity, which achieved the reduction rates of about 95% after 48 h, and the removal was free from the influence of proteinase K, heat, or EDTA. In the 42 d feeding experiment on broilers, the ratios of feed to gain were insignificantly different between the group C and group A. [Conclusion] This method achieved high rate of removing FG in CSM. The reason was the likelihood that the stable compounds in the cellular contents and supernatant of GJ00141 adsorb or bind to FG. Broilers grew well with the FCSM. Thus, it was an efficient detoxifying method for CSM.
文摘Organic biomass is an attractive feedstock for second generation alcohol production. Wild-type strains of the genus Candida showed capabilities different to produce alcohol fermenting a carbohydrates mixture （synthetic medium）, individually and in co-culture. Therefore, the main objective of this work was to evaluate the capability of Candida wild-type strains isolated from termite gut and rumen liquid, to ferment the most commonly carbohydrates presented in citrus residues, individually and in co-culture to alcohol production. C Tropicalis （LR4） presented higher percentage of carbohydrate consumption （74.20% ± 4.60%）, alcohol production （44.53 ± 0.01 gLl） and maximal alcohol productivity （6.40 ± 0.01 gL-l day） than C Glabrata （T1）. Co-culture schemas, CC1 （LR4： 60%; TI： 40%） and CC3 （first LR4 alone and 2 days later T1） presented the highest alcohol production （45.20 ± 1.30 gL-1 and 46.80 ± 2.60 gL-1, respectively）. Maximal alcohol productivity was obtained with CC2 （LR4： 80%; TI： 20%） and CC3 schemas, 7.70 ± 0.29 gL-1 day and 7.80 ± 0.44 gL-l day, respectively. The results suggest the usefulness of these wild-type strains in co-culture as an alternative to alcohol production from carbohydrates mixtures at concentrations commonly found in citrus waste.
基金Supported by Shandong Modern Agricultural Technology & Industry System
文摘[Objective] This study to aimed to investigate the effects of Cu stress on root exudates and microbial activities in rhizosphere of grafted and ungrafted cucum-ber seedlings, and therefore to elucidate the microbial mechanism of grafting for in-creasing cucumber plants tolerance to Cu stress [Method] Four treatments： （1） un-grafted seedlings ＋ test soil （U0）; （2） ungrafted seedlings ＋ test soil ＋ CuSO4·5H2O （U1）; （3） grafted seedlings ＋ test soil （G0）; （4） grafted seedlings ＋ test soil ＋ Cu-SO4·5H2O （G1） were set in the pot culture experiment. The contents of free amino acids, organic acids, phenolic acid and sugars, microbial population and enzyme ac-tivity in the four treatment were measured, respectively. [Result] The secretion of amino acids and organic acids were increased under Cu stress. The amino acids secretions of grafted seedlings roots were obviously higher than ungrafted seedlings except for Phe and Val. At the same time, the secretion of oxalic acid, malic acid, acetic acid, citric acid, cinnamic acid, ρ-hydroxybenzoic acid and benzoic acid of grafted seedlings were significantly higher than ungrafted seedlings as wel . There-fore, more Cu2＋ were restricted in soil by chelating, complexing and precipitation with root exudates, and its toxicity was decreased. The soil microbial biomass C and N in grafted cucumber rhizosphere were significantly higher than those in ungrafted cu-cumber rhizosphere, whereas basal respiration and metabolic quotient were signifi-cantly lower. Under Cu stress, the numbers of actinomyces and nitrogen fixing bac-teria decreased and the number of fungi increased significantly, whereas there was no significant difference in amounts of bacteria. The numbers of bacteria, actino-myces, and nitrogen fixing bacteria in grafted cucumber rhizosphere were significant-ly higher than those in ungrafted cucumber rhizosphere, but the number of fungi was opposite. The activities of soil urease, phosphatase, sucrase and catalase in grafted cucumber rhizosphere were significantly higher than those in ungrafted cu-cumber rhizosphere. [Conclusion] These indicated that the soil microbial environment and soil enzymes activities were improved by grafting under Cu stress, and as a re-sult, the adaptability of cucumber to Cu stress was improved.
