Potential of thin stillage as a low-cost nutrient source for direct cellulose fermentation by Clostridium thermocellum

AIMS Energy

Nazim Cicek¹  Rumana Islam¹  Charushi Panditharatne¹  David B. Levin¹  Richard Sparling²  John Schellenberg² 

[1] Department of Biosystems Engineering, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada;Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canad;

关键词: Dark fermentation;    thin stillage;    hydrogen;    ethanol;    cellulose;    Clostridium thermocellum;   

DOI  :  10.3934/energy.2015.4.711

来源: DOAJ

【 摘 要 】

Utilization of thin stillage (TS), derived from grain-based ethanol production, was investigated as an alternative source for microbial growth nutrients during direct conversion of cellulose by Clostridium thermocellum DSM 1237. Fermentation end-products synthesized by C. thermocellum grown on media prepared with various concentrations (50-400 g/L) of TS were compared to those synthesized by C. thermocellum grown on reagent grade chemical (reference) medium. Cell-growth in TS media, monitored with the aid of quantitative polymerase chain reactions (qPCR) technique, showed prolonged growth with increasing TS concentration. Final fermentation end-product concentrations from TS media were comparable with those from the reference medium despite lower growth-rates. The volumetric H₂ production generated by C. thermocellum grown with medium containing a low concentration (50 g/L) of TS matched the volumetric H₂ production by C. thermocellum grown in the reference medium, while higher concentrations (200 g/L) of TS resulted in greater synthesis of ethanol. Supplementation of TS-media with Mg⁺⁺ enhanced ethanol production, while hydrogen production remained unchanged. These results suggest that TS, an attractive source of low-cost nutrients, is capable of supporting the growth of C. thermocellum and that high concentrations of TS favor synthesis of ethanol over hydrogen from cellulose.

【 授权许可】

Unknown