黄海日照海域部分可培养细菌的分离、初步鉴定及产琼胶酶细菌的筛选

Isolation and identification of some cultivated bacteria from the sea area of Rizhao for screening of agarase-producing bacteria

摘要:

海洋细菌在海洋的物质与能量循环中起着非常重要的作用。为了适应复杂多变的海洋环境，海洋细菌在物种和基因方面表现出极高的丰富度。[目的] 对中国黄海日照海域部分可培养细菌进行分离、初步鉴定，同时筛选产琼胶酶菌株。[方法] 对从日照海域河流入海口和潮间带沙样和海水中分离到的73株细菌进行了16S rRNA基因序列测定，并进行序列同源性分析。同时检测了这些菌株对琼脂的降解能力。[结果] 结果显示，分离到的73株细菌属于4个门、13个科、34个属。18株细菌可能是新分类单元，其中16株为潜在新种，2株为可能的新属。73株细菌中，5株菌具有降解琼脂的能力，最高的琼胶酶活可达到2.17±0.04 U/mL，其中4株嗜琼胶属的细菌降解琼脂糖的产物均为新琼四糖。[结论] 本研究丰富了人们对黄海海域可培养细菌多样性的理解，为新物种和新酶的研究提供了基础，并为琼胶酶的提取提供了高产菌株。

关键词:可培养细菌;多样性;潜在新种;琼胶酶活性

Abstract:

Marine bacteria are the major members of marine life. Compared with those living on the land, marine bacteria exhibit high diversity in species, genes and ecological functions, valuable for both fundamental studies and biotechnological applications.[Objective] Isolation and identification of some culturable bacteria from the sea area of Rizhao for screening of agarase producing strains.[Methods] A total of 73 strains were isolated and their 16S rRNA genes were sequenced. Agarsae activity of agar-digesting strains was determined.[Results] These isolates belong to 34 genera, 13 family and 4 phyla, showing rich species diversity. Furthermore, 16S rRNA gene sequence analysis also showed that among these 73 strains, 18 strains potentially represented novel species. Our results also showed that 5 strains were positive for agarase activity and the highest agarase activity of these strains was determined to be 2.17±0.04 U/mL.[Conclusion] This study widens our understanding for the diversity of marine bacteria in species and agarase activity.

Key words:culturable bacteria;bacterial diversity;novel species;agarase activity