一株海藻多糖降解菌的分离与鉴定

Isolation and identification of a seaweed polysaccharide degrading bacteria strain

摘要:

【目的】从腐烂的褐藻中筛选一株海藻多糖降解菌，编号L206，分析其对不同多糖的降解能力。【方法】通过形态观察、生化单因子试验及16S rRNA基因鉴定细菌，DNS法测定海藻多糖降解酶活性等。【结果】海洋细菌L206，革兰氏阴性短杆菌，生长对数期为3?21 h，适宜生长的NaCl质量浓度为0?3% (质量体积比)；通过16S rRNA基因鉴定为白色噬琼胶菌(Agarivorans albus)；L206被海带粉诱导至72 h时，综合复合酶活力达到最大，其中淀粉酶活力最高(28.17 U/mL)，木聚糖酶次之(23.83 U/mL)。【结论】白色噬琼胶菌L206是一株多能型多糖降解菌，对褐藻多糖有特殊的降解能力，具有潜在开发价值。

Abstract:

[Objective] A bacterial strain, L206, which could degrade seaweed polysaccharides was isolated from the rotten brown algae. This research aims to analyze its ability to degrade different polysaccharides of seaweed. [Methods] The morphologic, biochemical and physiological characteristics and 16S rRNA gene were analyzed to identify the taxonomic position of strain L206. Then the activity of seaweed polysaccharide degrading enzyme was measured by DNS. [Results] The bacterial strain was a Gram-negative short bacillus. Its logarithmic growth phase was 3?21 h, with NaCl concentration range from 0 to 3% (w/v) for suitable growth. Phylogenetic analysis based on 16S rRNA gene sequence comparisons indicated that the strain L206 was Agarivorans albus. The comprehensive enzyme activity reached maximum level after strain L206 was induced for 72 h by the powder of Laminaria japonica, amylase present the highest enzymatic activity (28.17 U/mL), and followed by xylanase (23.83 U/mL). [Conclusion] As a multi-functional polysaccharide-degrading bacterium, Agarivorans albus L206 shows a special ability to degrading brown algae polysaccharide and has a great development potential.