Research of antibacterial activity and culturable bacteria isolate from mangrove rhizosphere soil in Maowei Sea

Abstract

In order to find culturable bacteria resources and antibacterial activity strain in the rhizosphere soil of mangrove plants from the Maowei Sea, the rhizosphere soil of five mangrove plants(Rhizophora stylosa, Talipariti tiliaceum, Sonneratia apetala, Aegiceras corniculatum, and Pluchea indica) was cultured by enrichment media and then isolated the culturable bacteria. The culturable bacteria were purified by six different isolation media. The diversity of culturable bacteria was analyzed by the 16S rRNA gene sequence information. Antimicrobial activities (Staphylococcus epidermidis, methicillin-resistant S. aureus, and Pseudomonas aeruginosa) of the culturable bacteria were analyzed by disk diffusion method. The results were as follows: (1) A total of 120 strains were isolated from seven rhizosphere soil samples of mangrove plants which could be classified into 35 families and 47 genera, among which five potential new species were obtained. The dominant genus was Streptomyces (14.2%). (2) It was found that the crude extracts of nine strains had antibacterial activity against at least one pathogen. The results indicate that there are abundant culturable bacteria and potential new antibiotics resources in the mangrove rhizosphere soils from the Maowei Sea.

Keywords

• mangrove plants
• rhizosphere soil
• enrichment culture
• cultured bacteria
• antibacterial activity