title: Ex situ product recovery for enhanced butanol production by Clostridium beijerinckii.
abstract: In situ butanol recovery fermentation has been intensively studied as an effective alternative to conventional butanol production, which is limited due to the cellular toxicity of butanol. However, the low biocompatibility of adsorbents often leads to failure of in situ recovery fermentations. In this study, Clostridium beijerinckii NCIMB 8052 was cultured in flasks without shaking and in situ recovery fermentation was performed by using an adsorbent L493. The amounts of acetone, butanol, and ethanol (ABE) increased by 34.4 % in the presence of the adsorbent. In contrast, cell growth and production of organic acids and ABE were retarded in the 7-L batch fermentations with in situ butanol recovery. Cell damage occurred in the fermentor upon agitation in the presence of the adsorbent, unlike in static flask cultures with in situ recovery. Ex situ recovery fermentation using circulation of fermentation broth after mid-exponential phase of cell growth was developed to avoid adsorbent-cell incompatibility. No apparent cell damage was observed and 25.7 g/L of ABE was produced from 86.2 g/L glucose in the fed-batch mode using 7 L fermentors. Thus, ex situ recovery fermentation with C. beijerinckii is effective for enhancing butanol fermentation.
authors: Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea.|R&D Center, GS Caltex Corporation, Daejeon, 34122, Republic of Korea.
authors: Sang-Hyun
authors: SH
authors: Lee
authors: R&D Center, GS Caltex Corporation, Daejeon, 34122, Republic of Korea.
authors: Moon-Ho
authors: MH
authors: Eom
authors: R&D Center, GS Caltex Corporation, Daejeon, 34122, Republic of Korea.
authors: Jin-Dal-Rae
authors: JD
authors: Choi
authors: Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea.
authors: Sooah
authors: S
authors: Kim
authors: Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea.
authors: Jungyeon
authors: J
authors: Kim
authors: R&D Center, GS Caltex Corporation, Daejeon, 34122, Republic of Korea.
authors: Yong-An
authors: YA
authors: Shin
authors: Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea. khekim@korea.ac.kr.
authors: Kyoung Heon
authors: KH
authors: Kim
mesh_terms: D000327:Adsorption; D000440:Butanols / Q000378:metabolism*; D046970:Clostridium beijerinckii / Q000378:metabolism*; D003470:Culture Media; D005285:Fermentation; D008855:Microscopy, Electron, Scanning
chemical_list: D000440:Butanols; D003470:Culture Media
keywords: Adsorbent; Butanol; Clostridium beijerinckii; Ex situ butanol recovery