초록
Escherichia coli produces molecular hydrogen (H<SUB>2</SUB>) during glucose or mixed carbon (glucose and glycerol) fermentation. Dependence of H<SUB>2</SUB> production rate (V<SUB>H'2</SUB>) on glucose at different pHs was studied in a concentration dependent manner. During growth of wild-type on glucose, increasing glucose concentration from 0.05% to 0.2% resulted in the marked inhibition of V<SUB>H'2</SUB>. Inhibitory effect of glucose was shown at pH 7.5 and 6.5 but not pH 5.5. However, glycerol added in the growth medium with 0.1% glucose significantly increased V<SUB>H'2</SUB> but different effects at different pHs were established upon glucose or glycerol assays. The results indicate that H<SUB>2</SUB> production is inhibited by glucose in a concentration dependent manner during glucose fermentation but glucose in combination with glycerol might enhance H<SUB>2</SUB> production during mixed carbon fermentation.