김창만 (Lawrence Berkeley National Laboratory, 전남대학교) | 한빛사논문 > 한빛사

한빛사논문

조회364

Lawrence Berkeley National Laboratory, 전남대학교

CV File 65 kb

Chem. Eng. J., Volume 456, 15 January 2023, 141028 | https://doi.org/10.1016/j.cej.2022.141028 Coupling gas purging with inorganic carbon supply to enhance biohydrogen production with Clostridium thermocellum

Changman Kim^a,b, Isaac Wolf^a, Chang Dou^a, Lauren Magnusson^c, Pin-Ching Maness^c, Katherine J. Chou^c, Steven Singer^d,e, Eric Sundstrom^a,e

^aAdvanced Biofuel and Bioproducts Process Development Unit, Lawrence Berkeley National Laboratory, Emeryville, CA 94608, USA
^bDepartment of Biotechnology and Bioengineering, Chonnam National University, Gwangju 61186, Republic of Korea
^cBiosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
^dJoint BioEnergy Institute, 5885 Hollis street, 4th floor, Emeryville, CA 94608, USA
^eBiological System Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94702, USA

Corresponding author: Eric Sundstrom

Abstract

Clostridium thermocellum is a desirable biocatalyst for biohydrogen production, with a native ability to simultaneously saccharify cellulose and to metabolize released cellodextrins for hydrogen production. During fermentation with C. thermocellum, partial pressures of two gases - CO2 and H2 - are critical drivers of overall reaction kinetics. Biohydrogen production is enhanced by maintaining a low hydrogen partial pressure, while high concentrations of dissolved CO2 promote microbial biomass synthesis. Our study evaluates the inherent trade-offs between hydrogen stripping and inorganic carbon supply for optimized biohydrogen synthesis. We find that nitrogen sparging at low flow rates increases hydrogen production when compared with an equivalent nitrogen overlay, but that high rates of nitrogen sparging inhibit cell growth and hydrogen production. Decreasing dissolved hydrogen partial pressure via nitrogen sparging also lowers the production of reduced metabolites, including lactate and ethanol. To address potential stripping of inorganic carbon from the production medium, we supplemented CO2 to the sparging gas and co-optimized for gas flow rate and for the CO2 fraction of the sparging gas. Total hydrogen production increased from 50 mmol∙L−1 in the base condition, when the bioreactor was sparged with 0.1 LPM of pure nitrogen, to 181.3 mmol∙L−1 when sparged with 1.3 LPM of 33 % CO2, demonstrating that biohydrogen production is highly sensitive to both parameters. Fine sensitivity of biohydrogen production to sparging conditions highlights the critical importance of bioreactor design and operation to achieve maximum H2 removal without compromising inorganic carbon supply to bacterial central metabolism.

논문정보

형식Research article
게재일2023년 01월 (BRIC 등록일 2023-01-03)
연구진국내+국외 연구진
분야 생명과학 > 생물공학

댓글 작성 로그인

CV 열람하기

연락처 보기