一株海洋贝类肠道琼胶降解菌的筛选与鉴定

Screening and identification of agarase-producing microbes in sea shellfish gut

以琼胶为唯一碳源,从海洋贝类肠道微生物共筛选出44株降解琼胶的海洋细菌,通过初筛和DNS法测定酶活得到一株产酶最高的菌株A-001,酶活力可达到13.01 U·m L-1.菌落形态为乳白色,革兰氏阴性菌,呈弯曲短杆状,通过微生物动力学实验,细菌A-001具有运动性.据生理生化特征和16Sr DNA序列可鉴定A-001为溶藻弧菌(Vibrio alginolyticus).

Agarase-producing microbes becomes hotspot for research and development on marine resources as agarase is mainly produced by microbes in sea shellfish gut. Agarose was used as the only carbon source. Forty-four strains of agar-degrading bacteria were initially screened from marine shelfish gut. Then 6 strains,which presented bigger transparent circle around colony by Lugosi iodine liquid staining than the rest,were re-screened. Among them,strain A-001 showed the maximum enzyme activity at 13. 01 U·m L- 1by DNS method. For the colony morphology,the strain A-001 was ivory,gram-negative and short rod. Through the dynamic experiment,the strain A-001 showed motility. Based on physiological and biochemical characteristics and 16 Sr DNA sequencing results,strain A-001 was identified as Vibrio alginolyticus.