南极菲尔德斯半岛潮间带沉积物细菌的多样性及分离菌产酶测定

Bacterial diversity and enzyme production by the bacteria isolated from the intertidal regions of the Fildes Peninsula,Antarctica

南极菲尔德斯半岛具有多种不同特征的生态地理微环境,如长城科考站、企鹅岛、生物湾与黄金湾流域、半岛南部、碧玉滩等。这些区域因水文地质、动植物分布、人类活动程度等不同而具有明显的生态地理差异。本研究从这些微环境海岸潮间带采集了7份代表性沉积物样品,采用16S rRNA基因高通量测序方法,对其细菌类群的多样性以及环境理化因子的影响进行了比较分析;同时采用常规可培养鉴定方法,对样品的分离菌株产酶状况进行了初步测定。结果表明:整体上看,所有样品的细菌类群主要分布在45门、104纲、442属当中,表现出比较高的多样性。其中,优势菌门Proteobacteria主要分布在半岛南部、碧玉滩和生物湾潮间带沉积物中,优势菌门Bacteroidetes主要分布在企鹅岛两侧和黄金湾潮间带沉积物,长城站潮间带沉积物的优势门为Firmicutes。相似生态微环境的潮间带沉积物具有不同的优势菌门和纲;而不同生态微环境潮间带沉积物却具相同的优势菌门和纲。有机氮(TON)、铵态氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(–)-N)、磷酸盐(PO_(4)^(3–)-P)、亚硝态氮(NO_(2)^(–)-N)含量与企鹅岛、生物湾、黄金湾潮间带沉积物的菌群多样性具有相关性,其中TON对生物湾样品的影响最大,而有机碳(TOC)对所有样品的影响均较小。分离菌株的产酶实验表明:在企鹅岛、生物湾、黄金湾等动物频繁出没的潮间带样品中,蕴藏着一批产淀粉酶、酪蛋白酶、脂肪酶、七叶苷酶、过氧化氢酶能力较强菌株,这为今后进一步的应用开发提供了宝贵的低温产酶菌株来源。

The Fildes Peninsula in Antarctica has diverse ecogeographical microenvironments possessing different characteristics,such as Great Wall Station,Penguin Island,Bio-bay,Golden Bay,south of the peninsula,and Biyu Beach.These regions have certain ecological and geographical differences owing to their distinct hydrogeology,flora and fauna distributions,and human activities.In this study,seven representative sediment samples were collected from coastal intertidal zones of these microenvironments,and the diversity of bacterial communities and the effects of environmental physicochemical factors were analyzed using the 16S rRNA gene high throughput sequencing method.Furthermore,the enzyme production status of culturable isolated strains was preliminarily determined.The results revealed that the bacterial groups in all samples were distributed throughout 45 phyla,104 classes,and 442 genera,indicating high bacterial diversity.Proteobacteria were primarily distributed in the southern region of the Peninsula,Biyu Beach,and Bio-bay intertidal zones,while Bacteroidetes were mainly distributed in the intertidal zones of Penguin Island and Golden Bay;Firmicutes was the dominant phylum in the intertidal regions of the Great Wall Station.Remarkably,intertidal regions with similar ecological microenvironments had different dominant phyla and classes.However,the intertidal regions from dissimilar ecological microenvironments had the same dominant phyla and classes.The organic nitrogen(TON),NH_(4)^(+)-N,NO_(3)^(–)-N,PO_(4)^(3–)-P,and NO_(2)^(–)-N contents were correlated with the bacterial group diversities at the Penguin Island,Biota Bay,and Golden Bay intertidalites.TON had the greatest impact on the Bio-bay intertidalite samples,while organic carbon had little effect on any of the samples.The enzyme producing analysis of the culturable isolated strains revealed a number of strains with a strong ability to produce amylase,casease,lipase,aesculin hydrolase,and catalase in the sediment samples of Penguin Island,Bio-bay,and Golden Bay.Thus,these isolates are valuable sources of low temperature,enzyme producing strains for further research.