海草床盐生植物根际土壤可培养细菌多样性及抑菌活性研究

Diversity and antibacterial activity of culturable bacteria from rhizosphere soil in seagrass bed halophytes

关键词:  海草床, 人类致病菌, 细菌多样性, 链霉菌属, 抑菌活性

Key words:  seagrass bed, human pathogenic bacteria, bacteria diversity, Streptomyces, antibacterial activity

摘要:

为探究海草床盐生植物根际土壤可培养细菌的新颖性和独特性及其代谢产物粗提物抑菌活性,该文采集防城港市珍珠湾和渔洲坪海草床9份盐生植物根际土壤进行研究,使用5种分离培养基,并采用稀释涂布法分离纯化可培养细菌。通过PCR扩增和16S rRNA测序进行菌种鉴定并对其进行多样性分析。采用滤纸片法筛选可培养细菌发酵粗提物对耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus)、表皮葡萄球菌(S. epidermidis)、金黄色葡萄球菌(S. aureus)和鲍曼不动杆菌(Acinetobacter baumannii)4种人类致病菌的抑制活性。结果表明:(1)从9份样品中共分离获得可培养细菌42株,隶属13个科14个属,包括链霉菌属、弧菌属、芽孢杆菌属、希瓦氏菌属、微杆菌属、短杆菌属、葡萄球菌属、鞘氨醇单胞菌属、罗思氏菌属、嗜冷杆菌属、假诺卡氏菌属、发光菌属、氟单胞菌属和志贺菌属,其中链霉菌属为优势菌属。(2)抑菌活性初筛结果显示,6株可培养细菌至少对2种以上人类致病菌有较强的抑制活性,其中1株来自弧菌属,1株来自罗思氏菌属,其余4株均来自链霉菌属。综上所述,防城港海域海草床盐生植物根际土壤微生物资源较新颖独特,链霉菌属细菌具有较强的抑菌活性,为开发新型抗生素提供了潜在菌种资源。

Abstract:

The purpose of this study was to investigate the novelty and particularly of the culturable bacteria in seagrass bed and study its antibacterial activity crude extracts of the metabolites. A total of nine rhizosphere soil samples were collected from the seagrass bed ecosystems in Pearl Bay and Yuzhouping, Fangchenggang City. Five different isolation media were used to isolate and purify the culturable bacteria using the dilution spread plate method. The bacterial species were identified through PCR amplification and 16S rRNA sequencing. The antibacterial activity against four human pathogenic bacteria(methicillin-resistant Staphylococcus aureus, S. epidermidis, S. aureus and Acinetobacter baumannii)were screened with Kirby-Bauer method. The results were as follows:(1)A total of 42 culturable bacteria were isolated, belonging to 14 genera and 13 families, which included Streptomyces, Vibrio, Bacillus, Shewanella, Microbacterium, Brevibacterium, Staphylococcus, Sphingomonas, Rothia, Psychrobacter, Pseudonocardia, Photobacterium, Halomonas, and Shigella. The genus Streptomyces was the dominant bacterium.(2)Antibacterial activity showed that six bacteria exhibited strong inhibitory activity against at least two or more human pathogenic bacteria, which included Vibrio(1 strain), Rothia (1 strain), and Streptomyces(4 strains). The studies show that the rhizosphere soil microbial resources of halophytes in the seagrass bed in Fangchenggang sea area are novel and unique, and Streptomyces has a strong antibacterial activity, which provides a new source for the research and development of new antibiotics drugs.