Tailoring bacterial cellulose structure through CRISPR interference‐mediated downregulation of galU in Komagataeibacter xylinus CGMCC 2955

• Published in: Biotechnology and bioengineering Vol. 117; no. 7; pp. 2165 - 2176
• Main Authors: Huang, Long‐Hui, Liu, Qi‐Jing, Sun, Xue‐Wen, Li, Xue‐Jing, Liu, Miao, Jia, Shi‐Ru, Xie, Yan‐Yan, Zhong, Cheng
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.07.2020
• Subjects: bacterial cellulose; Cellulose; CGMCC 2955; CRISPR; CRISPR interference; CRISPR‐dCas9; Gene expression; Genomes; Interference; Komagataeibacter xylinus; Metabolic flux; Oxygen tension; Pentose; Pentose phosphate pathway; Porosity; Strains (organisms); Synthesis; transcriptome; CGMCC 2955; Komagataeibacter xylinus; CRISPR interference; bacterial cellulose; transcriptome; CRISPR-dCas9
• ISSN: 0006-3592; 1097-0290; 1097-0290
• DOI: 10.1002/bit.27351

Diverse applications of bacterial cellulose (BC) have different requirements in terms of its structural characteristics. culturing Komagataeibacter xylinus CGMCC 2955, BC structure changes with alterations in oxygen tension. Here, the K. xylinus CGMCC 2955 transcriptome was analyzed under different oxygen tensions. Transcriptome and genome analysis indicated that BC structure is related to the rate of BC synthesis and cell growth, and galU is an essential gene that controls the carbon metabolic flux between the BC synthesis pathway and the pentose phosphate (PP) pathway. The CRISPR interference (CRISPRi) system was utilized in K. xylinus CGMCC 2955 to control the expression levels of galU. By overexpressing galU and interfering with different sites of galU sequences using CRISPRi, we obtained strains with varying expression levels of galU (3.20–3014.84%). By testing the characteristics of BC, we found that the porosity of BC (range: 62.99–90.66%) was negative with galU expression levels. However, the crystallinity of BC (range: 56.25–85.99%) was positive with galU expression levels; galU expression levels in engineered strains were lower than those in the control strains. Herein, we propose a new method for regulating the structure of BC to provide a theoretical basis for its application in different fields. Diverse applications of bacterial cellulose (BC) have different requirements in terms of its structural characteristics. In Komagataeibacter xylinus CGMCC 2955, a CRISPRi system was constructed to regulate the structure of BC by controlling the expression level of galU. The expression levels of galU was found to be negative with the porosity of BC, while positive with the crystallinity of BC.