The effects of two different phosphorus sources, corn steep liquor（CSL）and KH2PO4, on the growth of Candida glycerinogenes and glycerol production in batch fermentations were investigated. The glucose consumption in...The effects of two different phosphorus sources, corn steep liquor（CSL）and KH2PO4, on the growth of Candida glycerinogenes and glycerol production in batch fermentations were investigated. The glucose consumption in glycerol production, cell growth, maintenance, and byproducts formation during different fermentation phases was also analyzed kinetically.The results showed that the influence of CSL on cell growth and glucose consumption was so prominent that even minor variation of its quality or quantity caused much difference in experimental results. It was also found that the relationship between glycerol synthesis and cell growth was very close with CSL as phosphorus source,while it was rather loose with KH2PO4 as phosphorus source. With the increase in phosphorus concentration,glucose consumption in cell growth and maintenance was kept basically stable during the whole fermentation process. However,glucose consumption in glycerol production gradually decreased,and the byproducts which were mainly formed during the rapid growth phase increased. Further studies indicated that the yield of glycerol on glucose reached the peak of 53.44 % and 52.76 % with 14 g·L -1 CSL and 0.57 g·L -1 KH2PO4, respectively.Accordingly the yield of byproducts also decreased to the minimum value of 5.84 % and 4.25 %, respectively.展开更多
Glycerol production by repeated batch fermentation of Candida glycerinogenes was studied by using not only synthetic medium but also complex medium.The results showed that the increase rates of glycerol production,gly...Glycerol production by repeated batch fermentation of Candida glycerinogenes was studied by using not only synthetic medium but also complex medium.The results showed that the increase rates of glycerol production,glycerol yield on initial glucose and glycerol productivity were beyond 15.0%,15.0% and 37.0% when yeast cells are recycled 13 times in low phosphate synthetic medium,9 times in low phosphate complex medium and 14 times in low phosphate complex medium with supplemented trace elements,respectively.The number of recycling in low phosphate complex medium was fewer than that in low phosphate synthetic medium.It is because low phosphate synthetic medium only limited phosphate concentration,while low phosphate complex medium limited both trace elements and phosphate.The shortage of trace elements solution influenced cell growth and glycerol synthesis,and reduced recycling number of yeast cells in low phosphate complex medium.The limitation of phosphate concentration in repeated batch fermentation medium was helpful to promoting the ability of glycerol synthesis of C.glycerinogenes.展开更多
文摘The effects of two different phosphorus sources, corn steep liquor（CSL）and KH2PO4, on the growth of Candida glycerinogenes and glycerol production in batch fermentations were investigated. The glucose consumption in glycerol production, cell growth, maintenance, and byproducts formation during different fermentation phases was also analyzed kinetically.The results showed that the influence of CSL on cell growth and glucose consumption was so prominent that even minor variation of its quality or quantity caused much difference in experimental results. It was also found that the relationship between glycerol synthesis and cell growth was very close with CSL as phosphorus source,while it was rather loose with KH2PO4 as phosphorus source. With the increase in phosphorus concentration,glucose consumption in cell growth and maintenance was kept basically stable during the whole fermentation process. However,glucose consumption in glycerol production gradually decreased,and the byproducts which were mainly formed during the rapid growth phase increased. Further studies indicated that the yield of glycerol on glucose reached the peak of 53.44 % and 52.76 % with 14 g·L -1 CSL and 0.57 g·L -1 KH2PO4, respectively.Accordingly the yield of byproducts also decreased to the minimum value of 5.84 % and 4.25 %, respectively.
文摘Glycerol production by repeated batch fermentation of Candida glycerinogenes was studied by using not only synthetic medium but also complex medium.The results showed that the increase rates of glycerol production,glycerol yield on initial glucose and glycerol productivity were beyond 15.0%,15.0% and 37.0% when yeast cells are recycled 13 times in low phosphate synthetic medium,9 times in low phosphate complex medium and 14 times in low phosphate complex medium with supplemented trace elements,respectively.The number of recycling in low phosphate complex medium was fewer than that in low phosphate synthetic medium.It is because low phosphate synthetic medium only limited phosphate concentration,while low phosphate complex medium limited both trace elements and phosphate.The shortage of trace elements solution influenced cell growth and glycerol synthesis,and reduced recycling number of yeast cells in low phosphate complex medium.The limitation of phosphate concentration in repeated batch fermentation medium was helpful to promoting the ability of glycerol synthesis of C.glycerinogenes.
