To improve antagonistic metabolites production of Bacillus subtilis strain BS501a, physical parameters of fermentation and metal inorganic salts in medium, namely initial pH value, culture temperature, fermentation ti...To improve antagonistic metabolites production of Bacillus subtilis strain BS501a, physical parameters of fermentation and metal inorganic salts in medium, namely initial pH value, culture temperature, fermentation time, concentrations of CaC12, FeSO4, ZnSO4, MnSO4 and MgSO4, were optimized using one-factor-at-a-time and orthogonal tests. The results show that the optimal physical parameters of fermentation are an initial pH of 7.0, a culture temperature of 30 ~C, and a fermentation time of 48 h. The optimal concentrations of metal inorganic salts in basal medium are 10.2 mmol/L CaCl2, 0.4 mmol/L FeSO4, 3.5 mmol/L ZnSO4, 0.6 mmol/L MnSO4 and 2.0 mmol/L MgSO4. Among the metal inorganic salts, MgSO4 and MnSO4 play important roles in the improvement of the antagonistic metabolites production of B. subtilis strain BS501a; especially, MgSO4 contributes a highly significant effect. The average diameter of inhibition zone of the BS501a filtered fermentation supernatant （FFS） cultured in the optimal fermentation conditions against Magnaporthe grisea DWBJ329 reaches 71.4 mm, and there is 2.4-fold increase in antifungal activity as compared with 21.2 mm under the pre-optimized conditions.展开更多
The production of cellulase in Bacillus amyloliquefaciens UNPDV-22 was optimized using response surface methodology （RSM）. Central composite design （CCD） was used to study the interactive effect of culture conditi...The production of cellulase in Bacillus amyloliquefaciens UNPDV-22 was optimized using response surface methodology （RSM）. Central composite design （CCD） was used to study the interactive effect of culture conditions （temperature, pH, and inoculum） on cellulase activity. Results suggested that temperature and pH all have significant impact on cellulase production. The use of RSM resulted in a 96% increase in the cellulase activity over the control of non-optimized basal medium. Optimum cellulase production of 13 U/mL was obtained at a temperature of 42.24 ℃, pH of 5.25, and inoculum size of 4.95% （v/v） in a fermentation medium containing wheat bran, soybean meal and malt dextrin as major nutritional factors.展开更多
The disadvantages of the long term application of Tilemsi natural phosphate （TNP） on maize （Zea mays L.） production has come out because of its low P availability. Some functional soil microbes, such as phosphate ...The disadvantages of the long term application of Tilemsi natural phosphate （TNP） on maize （Zea mays L.） production has come out because of its low P availability. Some functional soil microbes, such as phosphate dissolving bacteria, have great potential in improvement of P solubility from TNP and P uptake by plants. The present study aimed to isolate and characterize typical phosphate dissolving bacterial strains （Bacillus subtilis） from Malian soils, and investigate their role in P uptake by maize grown in soils amended with TNP. The experimental design was a split plot with three main plots of fertilizers sources, i.e., natural phosphate, commercial fertilizer and without fertilizer, and with seven sub-plots of six microorganisms plus the control. The field experiment results have shown that the maize inoculated with the phosphate dissolving bacteria was improved in seed germination, plant growth, plant production （increase yield by 42%）, grain and aerial dry biomass （P） content of 34% and 64%, respectively. They have also shown that the locally available TNP can be used by the Malians farmers in maize culture and have comparable production to the one obtained with the costly imported commercial phosphate fertilizer, like the complex cereal. The project has provided information for the combined use of the Mali TNP and phosphate dissolving bacteria Bacillus subtilis subsp, subtilis （T）： DSM 10 in improvement of maize production in the country.展开更多
基金Project(2010A210003) supported by Henan Province Natural Sciences Research PlanProject(0910SGYS34370-2) supported by Zhengzhou City Science and Technology Research PlanProject supported by the Youth Backbone Teacher of Universities in Henan Province Grants Plan
文摘To improve antagonistic metabolites production of Bacillus subtilis strain BS501a, physical parameters of fermentation and metal inorganic salts in medium, namely initial pH value, culture temperature, fermentation time, concentrations of CaC12, FeSO4, ZnSO4, MnSO4 and MgSO4, were optimized using one-factor-at-a-time and orthogonal tests. The results show that the optimal physical parameters of fermentation are an initial pH of 7.0, a culture temperature of 30 ~C, and a fermentation time of 48 h. The optimal concentrations of metal inorganic salts in basal medium are 10.2 mmol/L CaCl2, 0.4 mmol/L FeSO4, 3.5 mmol/L ZnSO4, 0.6 mmol/L MnSO4 and 2.0 mmol/L MgSO4. Among the metal inorganic salts, MgSO4 and MnSO4 play important roles in the improvement of the antagonistic metabolites production of B. subtilis strain BS501a; especially, MgSO4 contributes a highly significant effect. The average diameter of inhibition zone of the BS501a filtered fermentation supernatant （FFS） cultured in the optimal fermentation conditions against Magnaporthe grisea DWBJ329 reaches 71.4 mm, and there is 2.4-fold increase in antifungal activity as compared with 21.2 mm under the pre-optimized conditions.
文摘The production of cellulase in Bacillus amyloliquefaciens UNPDV-22 was optimized using response surface methodology （RSM）. Central composite design （CCD） was used to study the interactive effect of culture conditions （temperature, pH, and inoculum） on cellulase activity. Results suggested that temperature and pH all have significant impact on cellulase production. The use of RSM resulted in a 96% increase in the cellulase activity over the control of non-optimized basal medium. Optimum cellulase production of 13 U/mL was obtained at a temperature of 42.24 ℃, pH of 5.25, and inoculum size of 4.95% （v/v） in a fermentation medium containing wheat bran, soybean meal and malt dextrin as major nutritional factors.
文摘The disadvantages of the long term application of Tilemsi natural phosphate （TNP） on maize （Zea mays L.） production has come out because of its low P availability. Some functional soil microbes, such as phosphate dissolving bacteria, have great potential in improvement of P solubility from TNP and P uptake by plants. The present study aimed to isolate and characterize typical phosphate dissolving bacterial strains （Bacillus subtilis） from Malian soils, and investigate their role in P uptake by maize grown in soils amended with TNP. The experimental design was a split plot with three main plots of fertilizers sources, i.e., natural phosphate, commercial fertilizer and without fertilizer, and with seven sub-plots of six microorganisms plus the control. The field experiment results have shown that the maize inoculated with the phosphate dissolving bacteria was improved in seed germination, plant growth, plant production （increase yield by 42%）, grain and aerial dry biomass （P） content of 34% and 64%, respectively. They have also shown that the locally available TNP can be used by the Malians farmers in maize culture and have comparable production to the one obtained with the costly imported commercial phosphate fertilizer, like the complex cereal. The project has provided information for the combined use of the Mali TNP and phosphate dissolving bacteria Bacillus subtilis subsp, subtilis （T）： DSM 10 in improvement of maize production in the country.
