一株致皮蛋“爆蛋”的嗜碱菌株分离鉴定及其De nove测序分析

Isolation and Identification of a Basophilic Bacterium BD from “Bursted” Pidan and De novo Sequencing Analysis of the Strain

摘要:

该研究采用传统微生物培养法从皮蛋“爆蛋”样品中分离出一株“致爆”菌BD菌株，经形态学观察、生理生化分析及16S rDNA测序比对，对菌株进行鉴定，并构建系统发育树。通过细菌学试验探究了菌株的生长性能、耐盐耐碱特点和产气能力，并对该菌进行De nove测序，获得菌株基因组框架图。结果表明，该菌16S rDNA序列与麦氏弧菌（Vibrio metschnikovii）同源性高达99.92%。该菌株最适生长温度为25~40 ℃，可在高碱（pH 12）环境下生长，具有产气能力。该菌株基因组大小为3.70 Mb，共编码3381个基因，对蛋白编码基因功能注释结果显示，该菌株基因组中含有大量碳水化合物代谢通路、膜转运功能相关通路基因，推测其在皮蛋内通过调节相关基因表达耐受高碱环境。BD菌株的碱耐受能力为其在皮蛋中增殖提供了有利条件，而其生理特点为皮蛋“爆蛋”控制提供依据，也为微生物高碱、高脂质环境适应相关功能基因的挖掘提供参考。

Abstract:

A Gram-negative bacterial strain named BD was isolated from the “bursted” Pidan by traditional microbial culture method. The strain was identified by morphological observation, biochemical analysis and 16S rDNA. The phylogenetic tree was also constructed. The growth performance, alkali resistance and the gas production capacity of the strain were investigated through bacteriological experiment. The whole genome of the strain was sequenced using De novo system and a draft map was obtained. The results showed that the physiological and biochemical characteristics of the strain were Vibrio genus, and the homology of 16S rDNA sequence with Vibrio metschnikovii reached 99.92%. This strain could grow in a high alkali (pH 12) environment, and the optimal growth temperature was 25~40 ℃. De nove sequencing of the strain showed that the genome size of the strain was 3.70 Mb, encoding 3381 genes in total. Functional annotation of protein-coding genes showed that the genome of this strain contained a large number of genes related to carbohydrate metabolism pathway and membrane transport function pathway. This study provides a theoretical basis for the development of the "burst" control scheme of Pidan processing, and provides a reference for the mining of functional genes related to the adaptation of microorganisms to high alkali and high lipid environment.