Effect of Organic Nitrogen Supplements on Syngas Fermentation Using Clostridium autoethanogenum

• Published in: Biotechnology and bioprocess engineering Vol. 26; no. 3; pp. 476 - 482
• Main Authors: Im, Hongrae, An, Taegwang, Kwon, Rokgyu, Park, Soeun, Kim, Young-Kee
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Society for Biotechnology and Bioengineering 01.06.2021; Springer Nature B.V; 한국생물공학회
• Subjects: Acetic acid; Acid production; bioprocessing; Biotechnology; carbon; Carbon sources; Chemistry; Chemistry and Materials Science; Clostridium; Clostridium autoethanogenum; culture media; Ethanol; ethanol production; Fermentation; Industrial and Production Engineering; microbial growth; Microorganisms; Nitrogen; Organic nitrogen; Peptones; Research Paper; Synthesis gas; tryptones; Yeast; yeast extract; 생물공학; peptone; bioethanol; syngas fermentation; tryptone
• ISSN: 1226-8372; 1976-3816
• DOI: 10.1007/s12257-020-0221-4

In this study, the effects of organic nitrogen supplements, such as tryptone and peptone, on microbial growth and ethanol and acetic acid production were investigated to improve ethanol productivity in a Clostridium autoethanogenum culture using syngas as the sole carbon source. The concentration of yeast extract, which is an organic nitrogen source in a basal medium, was optimized to 0.5 g/L before adding the supplements. In the C. autoethanogenum culture using tryptone and peptone as supplements, microbial growth and acetic acid formation were proportionate to the supplement concentration till up to 5.0 g/L of tryptone or peptone. However, ethanol concentration reached a maximum level of 4.57 g/L and 4.23 g/L in the cultures supplemented with 0.5 g/L of tryptone and 0.5 g/L of peptone, respectively. Ethanol production did not increase at a supplement concentration higher than 0.5 g/L. Thus, the addition of tryptone and peptone at a concentration of 0.5 g/L showed the best volumetric ethanol productivities (0.286 and 0.264 g/L·d, respectively), which were enhanced by 45.9% and 44.3% compared to the results of the control experiment.