Coordinated β-glucosidase activity with the cellulosome is effective for enhanced lignocellulose saccharification

Kuan Qi; Chao Chen; Fei Yan; Yingang Feng; Edward A Bayer; Akihiko Kosugi; Qiu Cui; Ya-Jun Liu

doi:10.1016/j.biortech.2021.125441

Coordinated β-glucosidase activity with the cellulosome is effective for enhanced lignocellulose saccharification

Bioresour Technol. 2021 Oct:337:125441. doi: 10.1016/j.biortech.2021.125441. Epub 2021 Jun 23.

Authors

Kuan Qi¹, Chao Chen¹, Fei Yan¹, Yingang Feng¹, Edward A Bayer², Akihiko Kosugi³, Qiu Cui¹, Ya-Jun Liu⁴

Affiliations

¹ CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Engineering Laboratory for Single Cell Oil, Qingdao Engineering Laboratory for Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
² Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel; Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 8499000, Israel.
³ Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan.
⁴ CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Engineering Laboratory for Single Cell Oil, Qingdao Engineering Laboratory for Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China. Electronic address: liuyj@qibebt.ac.cn.

PMID: 34182347
DOI: 10.1016/j.biortech.2021.125441

Abstract

Consolidated bio-saccharification (CBS) technology employs cellulosome-producing bacterial cells, rather than fungal cellulases, as biocatalysts for cost-effective production of lignocellulosic sugars. Extracellular β-glucosidase (BGL) expression in the whole-cell arsenal is indispensable, due to severe cellobiose inhibition of the cellulosome. However, high-level BGL expression in Clostridium thermocellum is challenging, and the optimal BGL production level for efficient cellulose saccharification is currently unknown. Herein, we obtained new CBS biocatalysts by transforming BGL-expressing plasmids into C. thermocellum, which produced abundant BGL proteins and hydrolyzed cellulose effectively. The optimal ratio of extracellular BGL-to-cellulosome activity was determined to be in a range of 5.5 to 21.6. Despite the critical impact of BGL, both excessive BGL expression and its assembly on the cellulosome via type I cohesin-dockerin interaction led to reduced cellulosomal activity, which further confirmed the importance of coordinated BGL expression with the cellulosome. This study will further promote industrial CBS application in lignocellulose conversion.

Keywords: Cellulosome; Clostridium thermocellum; Lignocellulose; Saccharification; β-glucosidase.

MeSH terms

Bacterial Proteins
Cellulosomes*
Clostridium thermocellum*
Lignin
beta-Glucosidase

Substances

Bacterial Proteins
lignocellulose
Lignin
beta-Glucosidase