Selective Isolation of Microbispora from Rhizhosphere Soil of Mangrove Plants

Abstract:

To selectively isolate Microbispora sp. from mangrove, 23 rhizosphere soils of different mangrove plants were collected in Wenchang, Hainan, China. After pretreatments of dry heat (100°C 60 min or 120°C 60 min) and treatment with Chloramine-T (1%, 30 min at room temperature) for each sample, 100 μL of the 10-1~10-3 dilutions of the resultant suspensions were transferred and spread onto the selective isolation media. GA and HV media were employed as the isolation media that supplemented with 0.5 mg/L multi-vitamin, 50 mg/L~100 mg/L K2Cr2O7, 50 mg/L cycloheximide and 50 mg/L nystatin. One hundred and ninety nine actinomycetes including 147 Streptomyces-like isolates and 52 non-Streptomyces-like isolates were isolated according to their morphology on agar plates and under microscope. Seven Streptomyces-like isolates and 28 non-Streptomyces-like isolates were putatively identified to genus level based on 16S rRNA gene sequence analysis, which belong to Microbispora(19), Streptomyces(7), Nonomuraea(4), Micromonospora(2), Streptosporangium(1), Asanoa(1), and one uncertain genus under Micromonosporaceae. It is found that plenty of Microbispora spp. inhabit in mangrove rhizoshere soil.