Self-assembly of CdS@C. Beijerinckii hybrid system for efficient lignocellulosic butanol production

Abstract

Bioproduction of butanol from lignocellulose has been considered as a sustainable and eco-friendly technology to cope with energy crisis and environmental issues. In the present research, a novel CdS@C. beijerinckii hybrid system was assembled by combining Clostridium beijerinckii NCIMB 8052 and the in situ formed CdS nanoparticles (NPs) to enhance the butanol production in ABE fermentation. 0.1 g/L of Cd(NO3)2·4H2O was identified for the effective in situ formation of CdS NPs. The in situ formed CdS NPs was powerful in generating photoelectrons which resulted in a significant upgradation of NADH/NAD+ in C. beijerinckii NCIMB 8052 under the visible irradiation of 2000 W/m2. With glucose and butyric acid as co-substrates, butanol production in the fermentation system of hybrid CdS@C. beijerinckii reached 10.42 ± 0.15 g/L, much higher than that of 8.08 ± 0.13 g/L in the fermentation system of C. beijerinckii NCIMB 8052. Butanol production from the mixed carbon source of saccharified liquid and acidogenic fermentation broth of rice straw was also improved by 23.6% in the hybrid system of CdS@C. beijerinckii, comparing to that of C. beijerinckii NCIMB 8052. The upgraded NADH/NAD+ was confirmed as the dominant factor for the enhanced butanol production. The research work provided an efficient fermentation process for the production of lignocellulosic butanol.