Diversity and antimicrobial potential of Actinobacteria isolated from diverse marine sponges along the Beibu Gulf of the South China Sea
Diversity and antimicrobial potential of Actinobacteria isolated from diverse marine sponges along the Beibu Gulf of the South China Sea
复制标题
南海北部湾不同海绵中分离的放线菌多样性及其抗菌潜力
DOI：
10.1093/femsec/fiz089
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发表时间：
2019-07-01
影响因子：
4.2
通讯作者：
Zhao, Jing
中科院分区：
文献类型：
--
作者：
Liu, Tan;Wu, Shufei;Zhao, Jing
海洋海绵相关微生物已被证明是一种非常有希望的生物活性和重要药用天然产品的来源。本研究调查了从南中国海域北部湾分离的49种海绵细菌的多样性和抑菌能力，这些海绵物种分属于16个属和几个未知的分类群。利用多种选择性培养基将363株不同形态的菌株鉴定为6个细菌分类群，包括变形杆菌(α亚群85和伽马亚群59)、放线杆菌(123)、非细菌(90)、拟杆菌(5)和短杆菌属(1)。ISP2和R2A型放线菌分离效果最好。经16S rDNA基因测序鉴定，123株放线菌分成21个属，其中大部分来自微杆菌属，其次是假单胞菌属、链霉菌属、科氏杆菌属、气微杆菌属、短杆菌属和诺卡氏菌属，占放线菌总数的82%。在最低限度的培养条件下，92株放线菌显示出抗菌活性，51株显示出中到强的抗菌活性，抑制了一半以上的受试细菌的生长。筛选与次级代谢产物相关的功能基因，发现10%(12/123)的放线菌含有PKS-KS基因，18%(22/123)含有NRPS-A基因，6%(7/123)含有PKS-NRPS基因簇。海绵Haliclona sp.、海绵Callyeasgia sp.Desmacella sp.，隶属于Demonsegiae纲；是优势宿主，具有最多样的放线菌属，具有更强的抗菌活性和更多样化的PKS/NRPS基因。
Marine sponge-associated microorganisms have proven to be a very promising source of biologically active and pharmaceutically important natural products. In this study, we investigated the diversity and antibacterial potential of bacteria from 49 sponge species isolated from the Beibu Gulf, South China Sea, belonging to 16 genera and several unidentified taxa. Using a variety of selective media, 363 strains with different morphologies were identified to six bacterial taxa, including Proteobacteria (alpha-subgroup 85 and gamma-subgroup 59), Actinobacteria (123), Firmicutes (90), Bacteroidetes (5) and Brevundimonas (1). Media ISP2 and R2A were the most effective for isolating Actinobacteria. One hundred and twenty-three actinobacterial strains clustered into 21 genera identified by 16S rDNA gene sequencing, most of which were from the genus Microbacterium, followed by Pseudonocardia, Streptomyces, Kocuria, Aeromicrobium, Brachybacterium and Nocardiopsis, constituted 82% of total actinobacterial isolates. By using the minimal medium, 92 actinobacterial isolates showed antimicrobial activities, and 51 strains displayed moderate to strong antimicrobial activity that inhibited the growth of more than half of the bacteria tested in this study. Functional genes related to secondary metabolites were screened, revealing that 10% (12/123) of actinobacterial isolates contained PKS-KS genes, 18% (22/123) harbored NRPS-A genes and 6% (7/123) had hybrid PKS-NRPS gene clusters. The sponges Haliclona sp., Callyspongia sp. and Desmacella sp., belonging to class Demonspongiae, and Leucaltis sp. from the class Calcarea, were dominant hosts, harboring the most diverse actinobacterial genera with stronger antimicrobial activities and more diverse PKS/NRPS genes.