In the course of γ-poly (glutamic acid) γ-PGA fermentation, metal ions K +,Mg 2+ ,Fe 3+ ,Ca 2+ ,Mo 6+ ,Mn 2+ ,Co 2+ and Zn 2+ in the medium have certain effects on the synthesis of γ-poly(glutamic acid).Excess or l...In the course of γ-poly (glutamic acid) γ-PGA fermentation, metal ions K +,Mg 2+ ,Fe 3+ ,Ca 2+ ,Mo 6+ ,Mn 2+ ,Co 2+ and Zn 2+ in the medium have certain effects on the synthesis of γ-poly(glutamic acid).Excess or lack of K +,Mg 2+ and Fe 3+ results in reduced yield of γ-PGA.It was found that the γ-PGA synthesis by Bacillus licheniformis was promoted obviously by Ca 2+ and Mo 6+ . Synthesis and stereochemical composition of γ-PGA was greatly regulated by Mn 2+ .γ-PGA was not produced without Mn 2+ in medium, and with the increase of Zn 2+ concentration the yield of γ-PGA and the proportion of D-glutamic acid in the peptide increase. Regulative effect of Co 2+ and Zn 2+ was almost the same as that of Mn 2+ , thus the combination of Mn 2+ , Co 2+ cann′t enhance γ-PGA synthesis and affect stereochemical composition of γ-PGA. Based on the experimental date, an appropriate formulation of metal ions in the medium for γ-PGA production was obtained.展开更多
文摘In the course of γ-poly (glutamic acid) γ-PGA fermentation, metal ions K +,Mg 2+ ,Fe 3+ ,Ca 2+ ,Mo 6+ ,Mn 2+ ,Co 2+ and Zn 2+ in the medium have certain effects on the synthesis of γ-poly(glutamic acid).Excess or lack of K +,Mg 2+ and Fe 3+ results in reduced yield of γ-PGA.It was found that the γ-PGA synthesis by Bacillus licheniformis was promoted obviously by Ca 2+ and Mo 6+ . Synthesis and stereochemical composition of γ-PGA was greatly regulated by Mn 2+ .γ-PGA was not produced without Mn 2+ in medium, and with the increase of Zn 2+ concentration the yield of γ-PGA and the proportion of D-glutamic acid in the peptide increase. Regulative effect of Co 2+ and Zn 2+ was almost the same as that of Mn 2+ , thus the combination of Mn 2+ , Co 2+ cann′t enhance γ-PGA synthesis and affect stereochemical composition of γ-PGA. Based on the experimental date, an appropriate formulation of metal ions in the medium for γ-PGA production was obtained.
