Enhancing cellulase biosynthesis of Bacillus subtilis Z2 by regulating intracellular NADH level

Summary: Optimizing cellulase biosynthesis in Bacillus subtilis is crucial for enhancing enzymatic yield in lignocellulosic biomass conversion. However, the regulatory mechanisms linking intracellular NAD(H/+) levels to cellulase production remain elusive. In this study, we systematically screened 1...

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Main Authors: Shuai Liu, Yi Li, Lin Quan, Hai-Xia Liu, Yang Luo, Yong-Zhong Wang
Format: Article
Language:English
Published: Elsevier 2025-05-01
Series:iScience
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Online Access:http://www.sciencedirect.com/science/article/pii/S2589004225006029
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author Shuai Liu
Yi Li
Lin Quan
Hai-Xia Liu
Yang Luo
Yong-Zhong Wang
author_facet Shuai Liu
Yi Li
Lin Quan
Hai-Xia Liu
Yang Luo
Yong-Zhong Wang
author_sort Shuai Liu
collection DOAJ
description Summary: Optimizing cellulase biosynthesis in Bacillus subtilis is crucial for enhancing enzymatic yield in lignocellulosic biomass conversion. However, the regulatory mechanisms linking intracellular NAD(H/+) levels to cellulase production remain elusive. In this study, we systematically screened 13 genes associated with NAD+ biosynthesis and NADH regeneration in B. subtilis Z2. Employing a modular engineering strategy with four distinct modules, we directed metabolic flux to enhance NAD+ biosynthesis and NADH regeneration. Key genes (ycel, nadV, nadM, mdh, and sucB) were identified, and their co-expression in B. subtilis Z2 resulted in a 13.09-fold increase in intracellular NADH levels and a consequential 2.24- and 2.04-fold enhancement in the filter paper-hydrolyzing (FPase [representing total cellulase]) activity and carboxymethylcellulose (CMCase [representing endoglucanase]) activity, respectively. Experimental validations, including antagonist LaCl3 treatment and spcF gene deletion, unequivocally established the calcium signaling pathway’s role in regulating cellulase gene overexpression in response to elevated intracellular NAD(H/+) levels.
format Article
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institution OA Journals
issn 2589-0042
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publishDate 2025-05-01
publisher Elsevier
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series iScience
spelling doaj-art-c5675913a39e4364a7d51ccdcc856e172025-08-20T02:17:34ZengElsevieriScience2589-00422025-05-0128511234110.1016/j.isci.2025.112341Enhancing cellulase biosynthesis of Bacillus subtilis Z2 by regulating intracellular NADH levelShuai Liu0Yi Li1Lin Quan2Hai-Xia Liu3Yang Luo4Yong-Zhong Wang5Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400030, ChinaKey Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400030, ChinaKey Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400030, ChinaChongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing 400030, China; Corresponding authorCenter of Smart Laboratory and Molecular Medicine, NHC Key Laboratory of Birth Defects and Reproductive Health, Jiangjin Hospital, School of Medicine, Chongqing University, Chongqing 400030, China; Corresponding authorKey Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400030, China; Corresponding authorSummary: Optimizing cellulase biosynthesis in Bacillus subtilis is crucial for enhancing enzymatic yield in lignocellulosic biomass conversion. However, the regulatory mechanisms linking intracellular NAD(H/+) levels to cellulase production remain elusive. In this study, we systematically screened 13 genes associated with NAD+ biosynthesis and NADH regeneration in B. subtilis Z2. Employing a modular engineering strategy with four distinct modules, we directed metabolic flux to enhance NAD+ biosynthesis and NADH regeneration. Key genes (ycel, nadV, nadM, mdh, and sucB) were identified, and their co-expression in B. subtilis Z2 resulted in a 13.09-fold increase in intracellular NADH levels and a consequential 2.24- and 2.04-fold enhancement in the filter paper-hydrolyzing (FPase [representing total cellulase]) activity and carboxymethylcellulose (CMCase [representing endoglucanase]) activity, respectively. Experimental validations, including antagonist LaCl3 treatment and spcF gene deletion, unequivocally established the calcium signaling pathway’s role in regulating cellulase gene overexpression in response to elevated intracellular NAD(H/+) levels.http://www.sciencedirect.com/science/article/pii/S2589004225006029Natural sciencesBiological sciencesBiotechnologyMicrobial biotechnologyEnzyme engineering
spellingShingle Shuai Liu
Yi Li
Lin Quan
Hai-Xia Liu
Yang Luo
Yong-Zhong Wang
Enhancing cellulase biosynthesis of Bacillus subtilis Z2 by regulating intracellular NADH level
iScience
Natural sciences
Biological sciences
Biotechnology
Microbial biotechnology
Enzyme engineering
title Enhancing cellulase biosynthesis of Bacillus subtilis Z2 by regulating intracellular NADH level
title_full Enhancing cellulase biosynthesis of Bacillus subtilis Z2 by regulating intracellular NADH level
title_fullStr Enhancing cellulase biosynthesis of Bacillus subtilis Z2 by regulating intracellular NADH level
title_full_unstemmed Enhancing cellulase biosynthesis of Bacillus subtilis Z2 by regulating intracellular NADH level
title_short Enhancing cellulase biosynthesis of Bacillus subtilis Z2 by regulating intracellular NADH level
title_sort enhancing cellulase biosynthesis of bacillus subtilis z2 by regulating intracellular nadh level
topic Natural sciences
Biological sciences
Biotechnology
Microbial biotechnology
Enzyme engineering
url http://www.sciencedirect.com/science/article/pii/S2589004225006029
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AT yili enhancingcellulasebiosynthesisofbacillussubtilisz2byregulatingintracellularnadhlevel
AT linquan enhancingcellulasebiosynthesisofbacillussubtilisz2byregulatingintracellularnadhlevel
AT haixialiu enhancingcellulasebiosynthesisofbacillussubtilisz2byregulatingintracellularnadhlevel
AT yangluo enhancingcellulasebiosynthesisofbacillussubtilisz2byregulatingintracellularnadhlevel
AT yongzhongwang enhancingcellulasebiosynthesisofbacillussubtilisz2byregulatingintracellularnadhlevel