艾丁湖可培养好氧嗜盐细菌多样性及抗辐射特征初探

The preliminary study of the diversity and radiation-resistant characteristics of culturable aerobic halophilic bacteria in the Aiding Lake

为了解新疆艾丁湖地区中可培养好氧嗜盐细菌的多样性及抗辐射相关特征,以去除盐组分的R2A为基础培养基,在NaCl浓度为50~300 g/L范围内对艾丁湖地区湖边滩涂沉积物和湖周盐碱地中可培养好氧嗜盐细菌进行分离。结果表明,经16S rRNA序列测定和系统进化分析,共得到80株好氧嗜盐细菌。湖周盐碱地的可培养好氧嗜盐细菌数量显著高于湖边滩涂沉积物,物种丰富度也显著高于湖边滩涂沉积物;其中,中度嗜盐菌不仅数量多且多样性丰富。分离所得的好氧嗜盐细菌隶属于厚壁菌门、放线菌门和变形菌门的22个属;其中,厚壁菌门(70.00%)是优势菌门,Bacillus(45.00%)是优势菌属。此外,还分离得到19株高度嗜盐的潜在新种。分离所得的80株可培养好氧嗜盐细菌中有34株在100 J/m2的UVC辐照后存活率(SR)大于10%,属于Bacillus的嗜盐-抗辐射细菌占25.00%;分离自100 g/L NaCl的Streptomyces sp.ALP-8和Streptomyces sp.ASS-29的抗辐射能力最强,SR分别为67.23%和65.73%;极端嗜盐细菌Staphylococcus sp.ASS-5(分离自300 g/L NaCl)、Sediminibacillus sp.ALP-17(分离自250 g/L NaCl)和Kocuria sp.ASS-27(分离自250 g/L NaCl)的SR也在50%以上。

In order to reveal the diversity and radiation-resistant related characteristics of the culturable aerobic halophilic bacteria in Aiding Lake of Xinjiang,R2A with the salt fraction removed was used as the basal medium to isolate aerobic halophilic bacteria in the mudflat sediment and saline land around the Aiding Lake area in the range of 50~300 g/L NaCl concentration.The results showed that80 strains of aerobic halophilic bacteria were obtained by 16S rRNA sequence and phylogenetic analysis.The number of culturable aerobic halophilic bacteria and the species richness in the saline land around the lake were significantly higher than those in the mudflat sediment.Among them,moderate halophilic bacteria were not only more abundant but also rich in diversity.The isolated aerobic halophilic bacteria belonged to 22 genera of the phyla Firmicutes,Actinobacteria and Proteobacteria.Among them,the Firmicutes(70.00%)was the dominant phylum and the Bacillus(45.00%)was the dominant genus.In addition,19 potential new species with high salinity were isolated.34 strains from the isolated 80 aerobic halophilic bacteria had a survival rate(SR)of more than 10% after UVC irradiation at 100 J/m2,and 25.00% of the halophilic radiation-resistant bacteria were Bacillus.Streptomyces sp.ALP-8 and Streptomyces sp.ASS-29 isolated from 100 g/L salt concentration were the most radiation-resistant,and SR was 67.23% and 65.73%respectively.The SR of extreme halophilic bacteria Staphylococcus sp.ASS-5(isolated from 300 g/L NaCl),Sediminibacillus sp.ALP-17(isolated from 250 g/L NaCl)and Kocuria sp.ASS-27(isolated from 250 g/L NaCl)was all above 50%.