大西洋鲑循环水养殖水体异养细菌组成的研究

采集养殖池水样,选取Zobell 2216E琼脂培养基、溶菌肉汤琼脂培养基、硫代硫酸盐柠檬酸盐胆盐蔗糖琼脂培养基、脑心浸液琼脂培养基、胰蛋白胨大豆琼脂培养基、营养琼脂培养基6种常见固体培养基进行细菌分离培养,以平板菌落计数法和菌落外观形态特征辨别及16SrRNA基因测序方法进行异养菌计数和种类组成分析。结果显示:(1)养殖池水体异养菌可分为4大类,分别属于变形菌门(包括α-、γ-变形菌纲)、厚壁菌门、拟杆菌门、放线菌门,其中以γ-变形菌纲为优势菌群。按属分类大多为假交替单胞菌属和弧菌属。(2)不同培养基分离菌落数量2216E培养基溶菌肉汤琼脂培养基胰蛋白胨大豆琼脂培养基脑心浸液琼脂培养基营养琼脂培养基硫代硫酸盐柠檬酸盐胆盐蔗糖琼脂培养基,且2216E培养基菌落数极显著高于其余5种培养基(P0.01);2216E培养基所分离细菌的种类最多,分属于12个属,假交替单胞菌属为优势类群,占比50%,弧菌属仅占3.13%;脑心浸液琼脂培养基、溶菌肉汤琼脂培养基、胰蛋白胨大豆琼脂培养基所分离细菌均以弧菌属为优势菌群,分别占33.33%、60%、25%;硫代硫酸盐柠檬酸盐胆盐蔗糖琼脂培养基所分离细菌仅分属于1个属,即弧菌属;营养琼脂培养基无弧菌,但有假单胞菌分离出。

Composition of Heterotrophic Bacteria in a Recirculating Aquaculture System for Atlantic Salmon (Salmo sal ar)

The aim of this work was to study the composition of heterotrophic bacteria in a Recirculating Aquaculture System(RAS)for Atlantic salmon (Salmo salar) and to compare the difference in bacterial isolation and cultivation in different culture media .The bacteria in water samples collected from the tanks were cultured in 6 types of medium in‐cluding 2216E ,BHI ,LB ,NA ,TSA ,and TCBS ,and composition and quantity of the bacteria were determined by a plate count method ,bacterial morphological identification and 16S rRNA gene sequencing analysis method .It was found that the heterotrophic bacteria in the tank water were divided into 4 major groups:Proteobacteria (including theα‐,γ‐Proteobacteria) ,Firmicutes ,Bacteroidetes ,and Actinobacteria ,with the dominant γ‐Proteobacteria ,especially the genera Pseudoal teromonas and Vibrio .The plate colony numbers in different media were shown as the order of 2216E >LB >TSA>BHI>NA> TCBS ,significantly higher in the 2216E than in the other 5 culture media (P<0 .01) .The bacteria isolated from 2216E culture medium belonged to 12 genera ,the maximal becteria in genus Pseud‐oalteromonas in accounting for 50% and genus Vibrio representing only 3 .13% .The genus Vibrio was the dominant genus in various culture media ,accounting for 33 .33% in BHI ,60% in LB ,25% in TSA and 100% in TCBS (only one genus V ibrio) ,but no V ibrio but Pseudomonas was isolated from NA culture mediuma .