In this study,ethanol production abilities of the novel carbon sources:sodium and calcium gluconate in different minimal and rich media were compared with glucose using Escherichia coli KO11.The strain produced higher...In this study,ethanol production abilities of the novel carbon sources:sodium and calcium gluconate in different minimal and rich media were compared with glucose using Escherichia coli KO11.The strain produced higher ethanol yield in the rich medium Luria-Bertani(LB)than the other two minimal media:corn steep liquor(CSL)and M9 for two substrates(sodium and calcium gluconate).Additionally,higher ethanol yields were achieved when the strain was grown in LB and M9 medium with calcium gluconate than sodium gluconate,while the ethanol yields were similar when both sodium and calcium gluconate were added into CSL medium respectively.Response surface methodology was used to optimize the fermentation medium components for enhancing ethanol production using strain E.coli KO11 in CSL medium with calcium gluconate as the substrate in batch culture.The concentration of the potassium phosphate buffer is the only significant factor among five factors considered.A quadratic model was developed to describe the relationship between ethanol production and the factors.The optimal conditions predicted for five factors were 14.38 g/L CSL,0.0398 g/L FeCl_(3)·6H2O,1.12 g/L MgSO_(4)·6H_(2)O,15.41 g/L(NH4)_(2)SO_(4),and 1.58/1.26 g/L KH_(2)PO_(4)/K_(2)HPO_(4)(2:1 molar ratio).The highest ethanol concentration under optimal conditions was 31.5 g/L,which was 5.6 g/L higher than that from the same fermentation concentration of calcium gluconate in LB media.The high correlation between the predicted and experimental values confirmed the validity of the model.展开更多
Response surface methodology was applied to optimize medium components for production of recombinant calf chymosin by Kluyveromyces lactis GG799.The previous data indicated that the most suitable carbon source,nitroge...Response surface methodology was applied to optimize medium components for production of recombinant calf chymosin by Kluyveromyces lactis GG799.The previous data indicated that the most suitable carbon source,nitrogen source,salt and vitamin were glucose,yeast extract,KH2PO4 and Ca D-Pantothenate,respectively.The concentration of four media components were optimized by using central composite design of response surface methodology.The optimum medium composition for recombinant calf chymosin production was found to contain glucose 29.84 g· L-1,yeast extract 19.85 g·L-1,KH2PO4 0.1 g·L-1 and Ca D-Pantothenate 4.49 mg·L-1.The enzyme activity of recombinant calf chymosin was 722 U· mL-1,which was in an excellent agreement with the predicted value(723 U·mL-1).The production of recombinant calf chymosin from Kluyveromyces lactis GG799 was effectively increased by response surface methodology.展开更多
The embryos of maize(Zea mays L.)inbred lines GS02,GS07,GS08,GS11 and GS15 were used as receptor materials to optimize the receptor system from the aspects of genotype,medium components and stress(PEG6000,mannitol,sal...The embryos of maize(Zea mays L.)inbred lines GS02,GS07,GS08,GS11 and GS15 were used as receptor materials to optimize the receptor system from the aspects of genotype,medium components and stress(PEG6000,mannitol,salt and low phosphorus).The results showed that GS07 had the highest induction rate(95.2%).Orthogonal test analysis showed that the best combination of medium components in induction was A2B3C1D3(2),namely,the concentration of 2,4-dichlorophenoxy acetic acid(2,4-D)was 4 mg·mL^(-1),the concentration of L-Proline(L-Pro)was 0.8 mg·mL^(-1),and the concentration of silver nitrate(AgNO3)was 10 mg·mL^(-1)(or 5 mg·mL).Interestingly,we found that the optimal medium supplemented with 30 g·L^(-1)PEG6000 or 80 g·L^(-1)mannitol was suitable for antioxidant enzyme activity and malondialdehyde(MDA)content in GS07 callus.Exogenous 10 mmol·L^(-1)Ca^(2+)in the medium components with 100 mmol·L^(-1)sodium chloride(NaCl)could improve the activity of antioxidant enzymes in GS07 callus.Callus of GS07 could divide normally and grow well in medium components with 27 mg·L^(-1)KH_(2)PO_(4).This study enhanced the adaptability of maize callus to stress and optimized the culture conditions.展开更多
基金California Energy Commission grant(55779A/08-03).
文摘In this study,ethanol production abilities of the novel carbon sources:sodium and calcium gluconate in different minimal and rich media were compared with glucose using Escherichia coli KO11.The strain produced higher ethanol yield in the rich medium Luria-Bertani(LB)than the other two minimal media:corn steep liquor(CSL)and M9 for two substrates(sodium and calcium gluconate).Additionally,higher ethanol yields were achieved when the strain was grown in LB and M9 medium with calcium gluconate than sodium gluconate,while the ethanol yields were similar when both sodium and calcium gluconate were added into CSL medium respectively.Response surface methodology was used to optimize the fermentation medium components for enhancing ethanol production using strain E.coli KO11 in CSL medium with calcium gluconate as the substrate in batch culture.The concentration of the potassium phosphate buffer is the only significant factor among five factors considered.A quadratic model was developed to describe the relationship between ethanol production and the factors.The optimal conditions predicted for five factors were 14.38 g/L CSL,0.0398 g/L FeCl_(3)·6H2O,1.12 g/L MgSO_(4)·6H_(2)O,15.41 g/L(NH4)_(2)SO_(4),and 1.58/1.26 g/L KH_(2)PO_(4)/K_(2)HPO_(4)(2:1 molar ratio).The highest ethanol concentration under optimal conditions was 31.5 g/L,which was 5.6 g/L higher than that from the same fermentation concentration of calcium gluconate in LB media.The high correlation between the predicted and experimental values confirmed the validity of the model.
基金Supported by Science and Technology Fund of Heilongjiang Province Education Department (11541018)
文摘Response surface methodology was applied to optimize medium components for production of recombinant calf chymosin by Kluyveromyces lactis GG799.The previous data indicated that the most suitable carbon source,nitrogen source,salt and vitamin were glucose,yeast extract,KH2PO4 and Ca D-Pantothenate,respectively.The concentration of four media components were optimized by using central composite design of response surface methodology.The optimum medium composition for recombinant calf chymosin production was found to contain glucose 29.84 g· L-1,yeast extract 19.85 g·L-1,KH2PO4 0.1 g·L-1 and Ca D-Pantothenate 4.49 mg·L-1.The enzyme activity of recombinant calf chymosin was 722 U· mL-1,which was in an excellent agreement with the predicted value(723 U·mL-1).The production of recombinant calf chymosin from Kluyveromyces lactis GG799 was effectively increased by response surface methodology.
基金the Science and Technology Project of Jilin Provincial Department of Education[JJKH20210351KJ,JJKH20210346KJ]Jilin Province Science and Technology Development Plan Project[20200402023NC]。
文摘The embryos of maize(Zea mays L.)inbred lines GS02,GS07,GS08,GS11 and GS15 were used as receptor materials to optimize the receptor system from the aspects of genotype,medium components and stress(PEG6000,mannitol,salt and low phosphorus).The results showed that GS07 had the highest induction rate(95.2%).Orthogonal test analysis showed that the best combination of medium components in induction was A2B3C1D3(2),namely,the concentration of 2,4-dichlorophenoxy acetic acid(2,4-D)was 4 mg·mL^(-1),the concentration of L-Proline(L-Pro)was 0.8 mg·mL^(-1),and the concentration of silver nitrate(AgNO3)was 10 mg·mL^(-1)(or 5 mg·mL).Interestingly,we found that the optimal medium supplemented with 30 g·L^(-1)PEG6000 or 80 g·L^(-1)mannitol was suitable for antioxidant enzyme activity and malondialdehyde(MDA)content in GS07 callus.Exogenous 10 mmol·L^(-1)Ca^(2+)in the medium components with 100 mmol·L^(-1)sodium chloride(NaCl)could improve the activity of antioxidant enzymes in GS07 callus.Callus of GS07 could divide normally and grow well in medium components with 27 mg·L^(-1)KH_(2)PO_(4).This study enhanced the adaptability of maize callus to stress and optimized the culture conditions.
