基于转录组揭示底酸促进巴氏醋杆菌产酸的分子机制

Transcriptomics Investigation of the Molecular Mechanism by Which Exogenous Acetic Acid Improves Acetic Acid Production in Acetobacter pasteurianus

以低体积分数底酸启动巴氏醋杆菌CICC 20001发酵醋酸,采用转录组学方法探讨底酸促进巴氏醋杆菌产酸的分子机制。研究结果表明,以0.5%底物醋酸启动醋酸发酵时,醋酸菌产酸效率明显提高,并筛选到482个显著差异表达基因,包括424个上调基因和58个下调基因。其中,在发酵早期和中后期,分别有412个和70个显著差异表达基因。添加0.5%底物醋酸时,巴氏醋杆菌可能通过尿素代谢、丙酸代谢、醋酸同化代谢强化醋酸耐受性,减少发酵过程中醋酸对菌体的毒害性作用,提高产酸效率。此外,巴氏醋杆菌还可能通过强化信号转导、膜运输和能量代谢,为醋酸发酵过程中营养物质转运和能量转化提供重要保障。研究结果将为底酸促进巴氏醋杆菌产酸机制提供新的认识,为提高醋酸发酵效益提供理论依据。

The enhancing effect of low concentrations of exogenous acetic acid on the fermentation of acetic acid by Acetobacter pasteurianus CICC 20001 was evaluated,and the underlying molecular mechanism was investigated using transcriptomics.The results showed that the acid production efficiency was significantly improved by addition of 0.5%acetic acid to the culture medium.A total of 482 significantly differentially expressed genes between the fermentations with and without 0.5%acetic acid were identified,of which 424 were up-regulated and 58 were down-regulated.In total 412 and 70 significantly differentially expressed genes were observed on days 1 and 7 of fermentation,respectively.Addition of 0.5%acetic acid to the culture medium could enhance the tolerance of A.pasteurianus to acetic acid by urea metabolism,propionic acid metabolism and acetic acid assimilation metabolism,reduce the toxic effect of acetic acid on the bacterium,and ultimately improve the acid production efficiency.In addition,strengthening the signal transduction,membrane transport and energy metabolism in A.pasteurianus may be important for nutrient transport and energy transformation in acetic acid fermentation.These results will provide new insights into the mechanism by which exogenous acetic acid enhances acid production by A.pasteurianus and provide a theoretical basis for improving the efficiency of acetic acid fermentation.