초록
Hydrogen producing novel bacterial strain was isolated from formation water from oil producing well. It was identified as Thermoanaerobacter mathranii A3N by 16S rRNA gene sequencing. Hydrogen production by novel strain was pH and substrate dependent and favored pH 8.0 for starch, pH 7.5 for xylose and sucrose, pH 8.0-9.0 for glucose fermentation at 70 <SUP>o</SUP>C. The highest H<SUB>2</SUB> yield was 2.64 +/- 0.40 mol H<SUB>2</SUB> mol glucose at 10 g/L, 5.36 +/- 0.41 mol H<SUB>2</SUB> mol - sucrose at 10 g/L, 17.91 +/- 0.16 mmol H<SUB>2</SUB> g - starch at 5 g/L and 2.09 +/- 0.21 mol H<SUB>2</SUB> mol xylose at 5 g/L. The maximum specific hydrogen production rates 6.29 (starch), 9.34 (sucrose), 5.76 (xylose) and 4.89 (glucose) mmol/g cell/h. Acetate-type fermentation pathway (approximately 97%) was found to be dominant in strain A3N, whereas butyrate formation was found in sucrose and xylose fermentation. Lactate production increased with high xylose concentrations above 10 g/L.