Go-culture of Clostridium beijerinckii L9 Clostridium butyricum Ml and Bacillus thermoamylouorans B5 for converting yeast waste into hydrogen

摘要

In order to enhance anaerobic hydrogen production from yeast waste, a series of 120-mL batch co-cultures of Clostridium beijerincfeii L9, Clostridium butyricum Ml, and Bacillus thermoamylouorans B5 under mesophilic conditions were established according to full factorial design (FFD) and mixture design (MD). The experimental results were subjected to multi-variate and response surface analyses to determine the relationships between bacteria converting yeast waste into hydrogen. The results indicated clearly that C. beijerincfeii L9 and C. butyricum Ml had significant potential to convert yeast waste into hydrogen. There was no significant hydrogen generation when B. thermoamylouorancs B5 alone was cultured with yeast waste. However, B. thermoamylouorancs B5 could significantly shorten the co-culture's hydrogen-producing lag phase. Response surface analyses demonstrate that B. thermoamylouorancs B5 can stimulate the specific hydrogen production rate of C. beijerincfeii L9 and C. butyricum Ml, greater in the case of the former than of the latter. An ultimate hydrogen yield of 46 mL H_2/g COD added yeast waste was obtained with an optimal volumetric ratio C. beijerincfeii L9: C. butyricum Ml: B. thermoamylouoranc B5 of 8.9:4.8:10.3. Highly reproducible co-culture results confirm that FFD and MD, via response surface analysis, are applicable to assess the roles of the individual microorganisms in the defined co-culture.