青贮乳酸菌类型和乳酸合成途径的研究进展

Research progress on types of lactic acid bacteria and lactic acid synthesis pathway in silage

青贮是乳酸菌在厌氧环境下,分解可溶性糖,生成乳酸,降低环境pH,同时抑制有害菌和霉菌生长的一种储存方法,其中乳酸发酵途径主要包括同型乳酸发酵和异型乳酸发酵两种,乳酸菌在发酵过程中起关键作用。已有的研究结果表明,乳酸杆菌属、片球菌菌属和魏斯氏菌属等是青贮过程中的主要优势菌属,是发酵中后期的优势功能微生物类群。目前对青贮过程的研究处于基础阶段,相关的研究主要集中在青贮中微生物群落结构、开发外源添加剂以及评价发酵品质等方面。文章从乳酸发酵途径、优良菌株的筛选和改造、关键基因以及乳酸合成调控等方面进行综述,为从菌株水平和分子水平调控青贮乳酸发酵途径、改善发酵品质,提供一定的参考价值。

Silage is a storage method for lactic acid bacteria to decompose soluble sugar,produce lactic acid,reduce environmental pH,and inhibit the growth of harmful bacteria and mold in anaerobic environment,lactic acid fermentation includes homogenous lactic acid fermentation and heterologous lactic acid fermentation.Lactic acid bacteria play a key role in the fermentation process,the results showed that Lactobacillus,Pediococcus and Weissella were the dominant species in the silage process and the dominant functional microorganisms in the middle and late stages of fermentation.At present,the research on the silage process is at the basic stage,and the related researches mainly focus on the microbial community structure,the development of exogenous additives and the evaluation of fermentation quality.In this paper,lactic acid fermentation pathway,screening and modification of excellent strains,key genes and regulation of lactic acid synthesis were reviewed,this study provides some reference value for the regulation of lactic acid fermentation and improvement of fermentation quality of silage at the level of strain and molecule.