Increased ethanol production by metabolic modulation of cellulose fermentation in Clostridium thermocellum

• Published in: Biotechnology letters Vol. 19; no. 8; pp. 819 - 823
• Main Authors: Sudha Rani, K, Swamy, M.V, Seenayya, G
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-08-1997; Springer Nature B.V
• Subjects: Acetic acid; Acetone; Acid production; bioenergy; Biological and medical sciences; Biotechnology; Cellulose; energy resources; Ethanol; Fermentation; Fundamental and applied biological sciences. Psychology; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; natural resources; Sodium; Ethanol; Hydrogen; Cellulose; Clostridiales; Environmental factor; Biofuel; Fermentation; Metabolism; Optimization; Sodium Azides; Clostridium thermocellum; Modulation; Clostridiaceae; Production; Bacteria; Yield; Acetone
• ISSN: 0141-5492; 1573-6776
• DOI: 10.1023/A:1018312931542

Significant quantitative differences in ethanol yields along with repression in acetic acid production were observed in Clostridium thermocellum strains SS21 and SS22 in the presence of H2, acetone and sodium azide. Exogenous H2 addition (1.0 atm) increased the ethanol yields to 0.40 g/g and ethanol to acetate ratio to 5.75 in strain SS21 but was inhibitory in strain SS22. Addition of acetone reversed the inhibition caused by H2 and increased the ethanol yields and ethanol to acetate ratio of strain SS22 up to 0.40 g/g and 7.9, respectively. Enhancement in ethanol yields up to 0.40 g/g and 0.41 g/g and ethanol to acetate ratio up to 3.63 and 8.1 were observed in the presence of 0.2 mM and 0.15 mM concentration of sodium azide by strains SS21 and SS22, respectively.