细菌纤维素(BC)是由细菌合成的生物聚合物,具有优异的特性,如高持水能力,结晶度高,和高纯度。它广泛用于食品,medical,化妆品,和功能性薄膜。木杆菌属是用于BC合成研究的模型菌株。在细菌中,运动性相关基因与BC合成相关,而在KomagataeibacterxylinusCGMCC2955中,运动相关基因的功能及其对BC合成的影响尚不清楚。为了解决这个差距,我们使用λRed重组系统单独敲除motA,motb,和mot2A分别,并构建了敲除菌株K.x-ΔmotA,K.x-ΔmotB,和K.x-Δmot2A。此外,motA和motB都被破坏以构建K.x-ΔmotAB突变体。结果表明,敲除菌株K.x-ΔmotAB表现出最高的BC产量,达到(5.05±0.26)g/L,与野生型菌株相比,增加了约24%。此外,由该菌株合成的BC表现出最低的孔隙率,54.35%,并表现出优异的机械性能,杨氏模量高达5.21GPa。由于敲除K.xylinusCGMCC2955中的motA和motB基因并没有降低BC产量;相反,它促进了BC的合成。因此,这项研究进一步加深了我们对乙酸细菌运动性与BC合成之间关系的理解。motA和motB基因的敲除导致BC孔隙度降低和机械性能改善。为BC合成和膜结构调控改性提供了参考。
Bacterial cellulose (BC) is a biopolymer synthesized by bacteria, which possess excellent characteristics such as high water holding capacity, high crystallinity, and high purity. It is widely used in food, medical, cosmetics, and functional films. Komagataeibacter xylinus is a model strain used in BC synthesis research. In bacteria, motility-related genes are associated with BC synthesis, whereas in Komagataeibacter xylinus CGMCC 2955, the functions of motility-related genes and their effects on BC synthesis are not known. To address this gap, we used the λ Red recombinant system to individually knock out motA, motB, and mot2A respectively, and constructed the knockout strains K. x-ΔmotA, K. x-ΔmotB, and K. x-Δmot2A. Additionally, both motA and motB were disrupted to construct the K. x-ΔmotAB mutant. The results demonstrated that knockout strain K. x-ΔmotAB exhibited the highest BC yield, reaching (5.05±0.26) g/L, which represented an increase of approximately 24% compared to wild-type strains. Furthermore, the BC synthesized by this strain exhibited the lowest porosity, 54.35%, and displayed superior mechanical properties with a Young\'s modulus of up to 5.21 GPa. As knocking out motA and motB genes in K. xylinus CGMCC 2955 did not reduce BC yield; instead, it promoted BC synthesis. Consequently, this research further deepened our understanding of the relationship between motility and BC synthesis in acetic acid bacteria. The knockouts of motA and motB genes resulted in reduced BC porosity and improved mechanical properties, provides a reference for BC synthesis and membrane structure regulation modification.