Isolation and Genetic Analysis of Halophilous Bacteria from Marine Sediment Collected at Tianjin Port, China  

中国天津港海底吹填淤泥中嗜盐细菌的分离及遗传分析（英文）

作　　者：ZHANG Guo-gang LIU Cheng-bao JIA Mei-qing HUANG Jing XIE Li-na YIN Xue SUI Xin 张国刚;刘成宝;贾美清;黄静;谢李娜;尹雪;隋鑫(天津师范大学生命科学学院,天津300387;天津师范大学动植物抗性实验室,天津300387;天津师范大学水资源重点实验室,天津300387)

机构地区：[1]College of Life Sciences,Tianjin Normal University,Tianjin 300387,PRC [2]Tianjin Key Laboratory of Animal and Plant Resistance,Tianjin Normal University,Tianjin 300387,PRC [3]Key laboratory of water resource and environment,Tianjin Normal University,Tianjin 300387,PRC

出　　处：《Agricultural Science & Technology》2018年第5期50-58,共9页农业科学与技术（英文版）

基　　金：天津市科技支撑项目(15ZCZDSF00410);天津市自然科学基金资助项目(12JCYBJC19700)~~

摘　　要：[Objective] Marine sediment from Tianjin Port has a extremely high salinity.The bacteria which live in such habitats have evolved distinct physiological,metabolic,and morphological characteristics to survive.The objective of this study is to identify all the specific salt-tolerant characteristics and the genetic evolution of the bacteria in the sediment.[Methods] In this study,the total DNA of sediment from Tianjin Port was extracted,and 16S rDNA was used to conduct an analysis of the fauna of sediment bacteria. We also isolated sediment bacteria using beef extract-peptone media with seven different NaCl concentrations (0,0.5%,2%,5%,10%,15%,and 20%),aiming to analyze the dominant species of halophilous bacteria under different salinities.[Results] 1) With each stepwise increase of salinity from 0.5% to 20%,the total number of isolated bacterial colonies decreased.14 strains of bacteria were identified and classified by the16S rDNA sequencing analysis.Of these,four could tolerate 0~2% salinity,four could tolerate 0~5% salinity,one could tolerate 0~15% salinity,and one tolerated within the full 0~20% salinity range.Further four strains were only able to tolerate within a few narrow salinity ranges.such as 5%~10%,10%~15%,10%~20% and 15%~20%;2) The quantity of bacteria strains that can be isolated from the marine sediment decreased with the increase of salinity. Also, the Shannon wiener index and species richness index of marine sediment bacteria decreased significantly from 5% salinity.However,there were no significant differences in the species evenness index;3) When the salinity was 0~10%,the dominant species was Bacillus.When the salinity was 15%, Halomonas was the dominant species.When the salinity was 20%,there were no significant differences in the proportions of these species.[Conclusion] Our results showed that some bacteria could tolerate living conditions with high salinity,and we even found a species which can tolerate a wide range of salinities (0~20%).In further study,it would be valuable to analyze the[目的]天津港海底吹填淤泥含盐量较高,生活在其中的细菌进化出了独特的生理,代谢和形态特征。本研究的目的是分离耐受高盐环境的细菌并分析淤泥细菌的遗传进化。[方法]对海底吹填淤泥进行总DNA的提取,采用16S rDNA进行土壤细菌区系分析。在此基础上再结合牛肉膏蛋白胨培养基,在7种不同NaCl浓度条件下(0,0.5%,2%,5%,10%,15%和20%)分离海底淤泥嗜盐细菌,并对耐受不同盐分含量的优势种群进行鉴定和遗传分析。[结果] 1)随着盐度逐步增加,分离得到的细菌菌落总数减少。通过测序鉴定并分类,得到14种细菌菌株。其中,4种可以耐受0～2%的盐度,4种可以耐受0～5%的盐度,1种可以耐受0～15%的盐度,1种可以耐受0～20%的盐度范围。其余的4种菌株仅能够耐受很窄的盐度范围(例如5%～10%,10%～15%,10%～20%和15%～20%)。2)随着盐度的增加,可从海洋沉积物中分离出的细菌菌株数量减少。此外,海底淤泥细菌的香农威纳指数和物种丰富度指数从5%盐度开始显著下降。但物种均匀度指数没有显著差异。3)当盐度范围为0～10%时,海底淤泥中的优势细菌种为芽孢杆菌。当盐度为15%时,优势种为盐单胞菌。当盐度为20%时,这些物种的比例没有显著差异。[结论]我们的研究结果表明,一些细菌可以耐受高盐度的生活条件,甚至有一种能够耐受大范围盐度(0～20%)。在进一步研究中,分析这些细菌独特的用于适应高盐度环境的生理生化功能将是有价值的,可以为促进海底淤泥中细菌种群资源的开发和耐盐微生物对盐渍化土壤的改良提供理论依据。

关 键 词：BACTERIA Marine sediment 16S rDNA gene sequence SALTTOLERANCE Genetic classification 

分 类 号：Q933[生物学—微生物学]