厦门海域产蛋白酶浮游细菌的多样性研究

Study on diversity of protease-producing planktonic bacteria in the Xiamen sea area

从厦门海域分离筛选到33株产蛋白酶浮游细菌,并通过对其16S 核糖体 RNA(16s rRNA)基因进行聚合酶链式反应(PCR)扩增和限制性片段长度多态性(RFLP)分析,初步研究了该海域产蛋白酶浮游细菌的多样性。研究发现,这33株菌可分为12种操作分类单元(OTU),其中 OTU-Ⅰ和 OTU-Ⅱ分别包含8株和12株菌株,分别占总菌数的24.2%和36.4%,为优势分离类群。分别从12种 OTU 中随机选取1株细菌作为代表进行16S rRNA 基因测序。序列分析结果显示,属于 OTU-Ⅶ的细菌为假交替单胞菌属(Pseu-doalteromonas sp.),而包括 OTU-Ⅰ和 OTU-Ⅱ在内的9种 OTU 都属于弧菌属(Vibrio sp.),表明弧菌在厦门海域产蛋白酶浮游细菌中占优势。初步的生理检测显示,这些细菌的适宜生长温度为16%左右,适宜生长盐度范围为3%～5%NaCl。

The diversity of protease-preducing planktonic bacteria in the Xiamen sea area was studied through a total of 33 protease-producing planktonic bacterial strains isolated from this sea area based on the method of polymerase chain reaction coupled with restriction fragment length polymorphism （PCR-RFLP） and the 16S ribosomal RNA （16S rRNA） gene sequencing. The results of PCR-RFLP indicate that these 33 strains can be grouped into 12 different operational taxonomic units （OTU）. OTU-Ⅰ and OTU-Ⅱ are the predominant OTUs, which contains 8 and 12 strains, respectively, accounting for 24.2% and 36.4% of the total protease-producing bacteria. A representative strain of each OTU was selected at ran- dom for 16S rRNA gene sequencing. The results show that the bacterial strains of OTU-Ⅷ belong to the genus Pseu- doalteromonas. Nine OTUs, including OTU-Ⅰ and OTU-Ⅱ, belong to the genus Vibrio, suggesting that Vibrio dominate in protease-producing planktonic bacteria in the Xiamen sea area. The results of physiology testing display that the optimum growth temperature is about 16℃ and the optimum growth salinity is about 3% -5% NaCl.