海绵共附生放线菌HNS054菌株的鉴定及发酵液抑菌活性研究

Identification and Bioactivity Screening of Streptomyces sp. HNS054 Associated with Marine Sponge Mycale sp.

海绵共生微生物是海洋活性化合物的重要来源之一,从广泛分布于福建沿海的山海绵(Mycale sp.)中分离可培养共附生微生物,并对其进行抑菌活性筛选,发现能产生抑菌活性物质的微生物,寻找具有潜在应用价值的化合物.从分离的64株细菌和21株放线菌海绵共附生微生物中,筛选到一株具有强烈拮抗革兰氏阳性菌的放线菌菌株HNS054,结合其培养特性、生理生化指标测定、孢子形态学观察及16SrRNA基因序列,看家基因atpD、recA、rpoB和trpB多基因联合分析,初步鉴定该菌为Streptomyces labedae.对该菌活性产物抑菌效价进行分析,结果表明:发酵液粗提物(1mg/mL)的抑菌能力略低于四环素(1mg/mL)和氨苄青霉素(1mg/mL),同万古霉素(1mg/mL)和环丙沙星(1mg/mL)相当,高于链霉素(1mg/mL).该活性物质对温度敏感,最高耐受温度为60℃;活性物质在碱性条件下稳定,酸性条件(pH≤3)下失活,分子排阻层析所得物质经全波段扫描,发现它在230nm有较高的吸收值.研究结果将为后续活性物质的进一步分离纯化奠定基础.

Sponge-associated bacteria are the potential sources of nature bioactive products. Marine sponge Mycale sp. is distributed throughout the intertidal zone of Fujian sea area which is located in the southeastern part of China. Large numbers of bacteria inclu- ding Actinobacteria group were isolated from Mycale sp. and test for antimicrobial activities was performed in previous study. Among all isolates,the strain HNS054 showed strong activities against Gram-positive bacteria. Multilocus sequence typing （MLST） by using the 16S rRNA,atpD, recA, rpoB and trpB genes identified strain HNS054 as Streptomyces labedae. Phenotypic observation and physiological characteristics further confirmed that HNS054 belong to S. labedae. Comparison with commercial antibiotics （Ampicillin,Streptomycin, CPFX, Vancomycin and Achromycin）, strain HNS054 exhibited more obvious antibacterial activities. Analysis of the crude extract of strain HNS054 including temperature-sensitive, tolerating high pH and exhibiting strong light absorption near 230 nm could provide data for further study.