Non-purified pH-dependent way to Enrich the Caproic acid-producing Genera Clostridium and Caproiciproducens from the Pit Mud and Huangshui

This study aimed to investigate the effect of different initial pH on the growth of caproic acid producing genera and the corresponding production of the main acids during the CSFB fermentation. Considering that the pH range of surface PM is from the minimum lower than 5 to the maximum about 7, four sets of experiments that simulate the environment of the CSFB fermentation in anaerobic bottles with pH original (blank), 5, 6, and 7 respectively were are designed. Our results demonstrate the optimum pH ranges for the enrichment of caproic acid-producing Clostridium and Caproiciproducens under the given circumstances. The results suggests how to selectively enrich the dominant caproic acid-producing flora in non-purified way, which could help improve the quality of CSFB fermentation.