Soil salinization affecting different crops is one of the serious threats to global food security.Soil salinity affects 20%and 33%of the total cultivated and irrigated agricultural lands,respectively,and has been repo...Soil salinization affecting different crops is one of the serious threats to global food security.Soil salinity affects 20%and 33%of the total cultivated and irrigated agricultural lands,respectively,and has been reported to caused a global crop production loss of 27.3 billion USD.The conventional approaches,such as using salt-tolerant varieties,saline soil scrapping,flushing,leaching,and adding supplements (e.g.,gypsum and lime),often fail to alleviate stress.In this context,developing diverse arrays of microbes enhancing crop productivity under saline soil conditions without harming soil health is necessary.Various advanced omics approaches have enabled gaining new insights into the structure and metabolic functions of plant-associated beneficial microbes.Various genera of salt-tolerating rhizobacteria ameliorating biotic and abiotic stresses have been isolated from different legumes,cereals,vegetables,and oil seeds under extreme alkaline and saline soil conditions.Rapid progress in rhizosphere microbiome research has revived the belief that plants may be more benefited from their association with interacting diverse microbial communities as compared with individual members in a community.In the last decade,several salt-tolerating plant growth-promoting rhizobacteria (PGPR) that improve crop production under salt stress have been exploited for the reclamation of saline agrosystems.This review highlights that the interaction of salt-tolerating microbes with plants improves crop productivity under salinity stress along with potential salt tolerance mechanisms involved and will open new avenues for capitalizing on cultivable diverse microbial communities to strengthen plant salt tolerance and,thus,to refine agricultural practices and production under saline conditions.展开更多
Kinetics of glycerol production by fermentation with osmotolerant yeast Candida krusei was studied. Suppositions of cell negative effect on and glucose inhibition in specific growth rate and glycerol assumption for en...Kinetics of glycerol production by fermentation with osmotolerant yeast Candida krusei was studied. Suppositions of cell negative effect on and glucose inhibition in specific growth rate and glycerol assumption for energy maintenance were made. Based on the suppositions, a set of unstructured kinetic models including cell groWth, glucose consumption and glycerol accumulation rate was proposed. To avoid the significant decrease of produced glyccerol in the latter fermentation stage, the fermentation was suggested to be ended when the concentration ratio of glycerol to glucose is close to 7.展开更多
Candida krusei was osmotolerant yeast for the production of glycerol. Extracellular osmotic pressure was one of the key factors to induce the enzyme activity of glycerol-3-phosphate dehydrogenase(GPDH) which se- verel...Candida krusei was osmotolerant yeast for the production of glycerol. Extracellular osmotic pressure was one of the key factors to induce the enzyme activity of glycerol-3-phosphate dehydrogenase(GPDH) which se- verely affected the glycerol productivity. Three osmoregulators such as NaCl, PEG4000 and glycerol were used to investigate their effects on yeast growth, glucose consumption and glycerol production. In order to determine the effect of extracellular glycerol concentration, different amounts of glycerol were initially supplemented as an os- moregulator to increase glycerol production. The maximum glycerol concentration attained 179g L-1 with initial glycerol concentration of 80g L-1 in medium, compared with 41g L-1 in the control experiment. These results were successfully reproduced for fed-batch process in an air-lift reactor.展开更多
Candida krusei was osmotolerant yeast for the production of glycerol. Extracellular osmotic pressure was one of the key factors to induce the enzyme activity of glycerol-3-phosphate dehydrogenase（GPDH） which severel...Candida krusei was osmotolerant yeast for the production of glycerol. Extracellular osmotic pressure was one of the key factors to induce the enzyme activity of glycerol-3-phosphate dehydrogenase（GPDH） which severely affected the glycerol productivity. Three osmoregulators such as NaCl, PEG4000 and glycerol were used to investigate their effects on yeast growth, glucose consumption and glycerol production. In order to determine the effect of extracellular glycerol concentration, different amounts of glycerol were initially supplemented as an osmoregulator to increase glycerol production. The maximum glycerol concentration attained 179g·L^-1 with initial glycerol concentration of 80g·L^-1 in medium, compared with 41g·L^-1 in the control experiment. These results were successfully reoroduced for fed-batch orocess in an air-lift reactor.展开更多
文摘Soil salinization affecting different crops is one of the serious threats to global food security.Soil salinity affects 20%and 33%of the total cultivated and irrigated agricultural lands,respectively,and has been reported to caused a global crop production loss of 27.3 billion USD.The conventional approaches,such as using salt-tolerant varieties,saline soil scrapping,flushing,leaching,and adding supplements (e.g.,gypsum and lime),often fail to alleviate stress.In this context,developing diverse arrays of microbes enhancing crop productivity under saline soil conditions without harming soil health is necessary.Various advanced omics approaches have enabled gaining new insights into the structure and metabolic functions of plant-associated beneficial microbes.Various genera of salt-tolerating rhizobacteria ameliorating biotic and abiotic stresses have been isolated from different legumes,cereals,vegetables,and oil seeds under extreme alkaline and saline soil conditions.Rapid progress in rhizosphere microbiome research has revived the belief that plants may be more benefited from their association with interacting diverse microbial communities as compared with individual members in a community.In the last decade,several salt-tolerating plant growth-promoting rhizobacteria (PGPR) that improve crop production under salt stress have been exploited for the reclamation of saline agrosystems.This review highlights that the interaction of salt-tolerating microbes with plants improves crop productivity under salinity stress along with potential salt tolerance mechanisms involved and will open new avenues for capitalizing on cultivable diverse microbial communities to strengthen plant salt tolerance and,thus,to refine agricultural practices and production under saline conditions.
基金Supported by the National Programs for High Technology Research and Development of China(2006AA10A212)the Key Project of Chinese National Programs for Fundamental Research and Development(2009CB118904)the the Research Foundation of Southwest University(SWUB2008072)~~
基金From National Ninth Five Years Project (NO. 96-03-03-03A).
文摘Kinetics of glycerol production by fermentation with osmotolerant yeast Candida krusei was studied. Suppositions of cell negative effect on and glucose inhibition in specific growth rate and glycerol assumption for energy maintenance were made. Based on the suppositions, a set of unstructured kinetic models including cell groWth, glucose consumption and glycerol accumulation rate was proposed. To avoid the significant decrease of produced glyccerol in the latter fermentation stage, the fermentation was suggested to be ended when the concentration ratio of glycerol to glucose is close to 7.
基金National Natural Science Foundation of China (No.20576118).
文摘Candida krusei was osmotolerant yeast for the production of glycerol. Extracellular osmotic pressure was one of the key factors to induce the enzyme activity of glycerol-3-phosphate dehydrogenase(GPDH) which se- verely affected the glycerol productivity. Three osmoregulators such as NaCl, PEG4000 and glycerol were used to investigate their effects on yeast growth, glucose consumption and glycerol production. In order to determine the effect of extracellular glycerol concentration, different amounts of glycerol were initially supplemented as an os- moregulator to increase glycerol production. The maximum glycerol concentration attained 179g L-1 with initial glycerol concentration of 80g L-1 in medium, compared with 41g L-1 in the control experiment. These results were successfully reproduced for fed-batch process in an air-lift reactor.
基金Supported by the National Natural Science Foundation of China （No.20576118）.
文摘Candida krusei was osmotolerant yeast for the production of glycerol. Extracellular osmotic pressure was one of the key factors to induce the enzyme activity of glycerol-3-phosphate dehydrogenase（GPDH） which severely affected the glycerol productivity. Three osmoregulators such as NaCl, PEG4000 and glycerol were used to investigate their effects on yeast growth, glucose consumption and glycerol production. In order to determine the effect of extracellular glycerol concentration, different amounts of glycerol were initially supplemented as an osmoregulator to increase glycerol production. The maximum glycerol concentration attained 179g·L^-1 with initial glycerol concentration of 80g·L^-1 in medium, compared with 41g·L^-1 in the control experiment. These results were successfully reoroduced for fed-batch orocess in an air-lift reactor.
