Isolation Of Actinomycetes From The Rhizosphere Of Cephalotaxus Fortunei And Screening, Identification Of Antibacterial Activity Strains

The medicinal part of the medicinal plants is generally in the root, and some special components penetrate into the root of the plant in the process of its growth, so that the rhizosphere has become a unique micro ecological environment,with population diversity of actinomycetes,so research on the isolation of actinomycetes from the rhizosphere of medicinal plants is become a hot of the most popular research topic.This study was adopted the rhizosphere soil of medicinal gymnosperms Cephalotaxaceae fortunei which collected from the Tiantai Mountain of Qinling Mountains( Hanzhong City, Shaanxi Province) as material.Four kinds of culture medium including 1/10ATCC-172、trehalose-proline、SLM、HV were used to isolate actinomycetes,and the 75.0 mg / L potassium dichromate, 100.0 mg / L nystatin and 20.0 mg / L nalidixic acid were used as inhibitors,finally 35 strains of actinomycetes were received, 65.7% actinomycetes were isolated from 1/10ATCC-172 with the best effect. According to the cultural characteristics, colony size, color and hyphal,the 35 strains of actinomycetes in the rhizosphere soil were identified preliminary as Streptomyces( 20 strains) and Micromonospora( 15 strains), each accounted for 57.1%, 42.9%, Streptomyces was the dominant strain.The antagonist activities of the 35 strains of actinomycetes fermentation liquid to five kinds of common pathogenic bacteria was studied by filter paper method.The result showed that there were 16 strains of actinomycetes with different degrees of antibacterial activity, which accounted for 45.7%.Among them, 10 strains had stronger antibacterial activity(inhibiting effect on three and more than three kinds of target bacteria),which accounted for 28.6% of the total isolates.Identified the strains that with obviously antagonist activity through the training features observation and 16 S rDNA analysis methods preliminarily and constructed phylogenetic tree.The result showde that there were 6 strains of the genus Streptomyces,10 strains of the genus Micromonospora.