几种海藻表面附着细菌的分离及其gyrB基因序列分析

Isolation of adhesive bacteria strains on surfaces of several algal species and gyrB gene sequences analysis

利用TCBS培养基从三种海藻:孔石莼(Ulva pertusa)、海带苗(Laminaria japonica)和多管藻(Polysiphonia urceolata)表面共分离得到10株细菌。生理生化试验和gyrB基因序列分析结果表明10株细菌都属于弧菌(Vibrio)。基于gyrB基因序列构建的系统发生树显示,菌株L5、L6、P7、P8、P10、P11、P12与Vibrio splendidus属于同一分支,序列间相似性为97.5-100%。菌株L4、P9与Vibrio cyclitrophicus属于同一分支,序列间完全一致。菌株U3在系统发生树上独立构成一个分支。本文结果表明不同海藻表面的附着细菌组成也不相同,具有一定的海藻特异性。

Ten adhesive bacteria strains were obtained from the surfaces of three algae species ： Ulva pertusa, Laminaria japonica and Polysiphonis urceolata with TCBS media. Based on the physico-biochemistry features, the gyrB phylogenetic analysis show clearly that all of the isolates belongs to genus Vibrio. On the gyrB gene sequences-based phylogenetic tree, strains LS, 1.6, P7, PS, P10, P11, and P12 are close to Vibrio splendidus and the similarity among the sequences ranges from 97.5% to 100%. Strains L4 and P9 show the close genetic relationships with Vibrio cyclitrophicus and the similarity among the sequences are 100% ,while strain U3 forms a branch alone on the system tree. The results show that the adhesive bacteria on surface vary in the algae species, which is, to some extents, algae species specific.