초록
<P>The production of biohydrogen from rice mill wastes, including rice bran and rice mill effluent by <I>Clostridium acetobutylicum</I> NCIM 2877 was investigated in a batch culture system and optimized the temperature and pH conditions. At 35 °C with initial pH of 5.2 a yield of 55.7±0.8 ml with 88.6 ± 0.3% substrate utilization and at pH 6 the production was 68.7 ± 0.9 ml with 85 ± 1.0 % substrate utilization. Addition of metal ions resulted in better yield and substrate utilization efficiency of the bacteria. FeSO4.7H2O at a concentration of 50 mg/l gave 79.7 ± 1.5 ml with 96% of substrate utilization. Cobalt effected the production greatly by giving 96.3 ± 0.9 ml with 95.3 ± 0.7% of substrate utilization whereas Nickel didn’t showed much effective results by giving only a maximum of 74.7 ± 1.5 ml production at 25 mg/l concentration. Conclusively, it can be stated that rice mill wastes can be used as a substrate and use of metal ions will play a key role in the enhancement of biohydrogen production.</P>