Effect of substrate concentration on the competition between Clostridium and Lactobacillus during biohydrogen production

• Published in: International journal of hydrogen energy Vol. 43; no. 25; pp. 11460 - 11469
• Main Authors: Park, Jeong-Hoon, Kim, Do-Hyung, Kim, Sang-Hyoun, Yoon, Jeong-Jun, Park, Hee-Deung
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 21.06.2018
• Subjects: Biohydrogen; Clostridium; Lactobacillus; Organic acids; Substrate competition; Substrate concentration; Clostridium; Substrate concentration; Biohydrogen; Substrate competition; Organic acids; Lactobacillus
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2017.08.150

To evaluate the effect of substrate concentration on competition between hydrogen producing bacteria and lactic acid bacteria during hydrogen fermentation, a series of batch tests was conducted using galactose or glucose as a carbon source. Clostridium butyricum, Lactobacillus casei, and mixture of the two species were used for inoculum, respectively. The batch tests based on single species revealed that C. butyricum utilized galactose faster than L. casei, regardless of substrate concentration (0.2–5.7 g/L), while L. casei utilized glucose faster than C. butyricum at low levels of glucose (<1 g/L). These trends were also observed in the batch test based on a mixture of the two species. L. casei outcompeted C. butyricum only when glucose was provided at low concentration. Taken together, the results suggest that failure of biohydrogen production can occur at low glucose concentration via outcompeting of lactic acid bacteria over hydrogen producing bacteria. •Clostridium used galactose faster than Lactobacillus regardless of initial levels.•Lactobacillus used glucose faster than Clostridium at low initial concentrations.•Lactobacillus had a competitive advantage over Clostridium at low initial glucose.•Low levels of glucose can cause a failure of biohydrogen production.