A study on isolated endophytic bacteria from Glycine sp. and their role on control of some plant pathogenic fungi

Introduction: The endophytic bacteria are group of bacteria, which live in plants tissues without any apparent harmful effects to the plants. Recently they have been isolated from different parts of plants with capability to produce anti fungi or bacterial activity. Nowadays, the endophytes instead of the fertilizers and germicidal chemical substances are used in agriculture hence the present study evaluated the presence of these organism in Glycine sp. in order to investigate their possible antifungal metabolites. Materials and methods: First, in the present study, endophytic bacteria were isolated from the stems and leaves of soybean using serial dilutions on the brain heart infusion agar .Then, the isolates were evaluated for ability to produce anti microbial metabolites against two fungal pathogens: Alternaria alternate (PTCC 5224) and Fusarium solani (PTCC 5284) based on parallel streak and well diffusion agar methods .The bacterial strains with ability to produce antimicrobial metabolites were identified using Api 20E, 20NE kites and then their growth curves were studied.Results: Totally, 39 bacterial endophytes were isolated from stem and leaves of the soybean plants among wich 20 belonged to the stems and 19 were isolated from the leaves. Among, all bacterial isolates 3 showed the antimicrobial effect which identified with Api kits and they belonged to the genus of Pseudomonas. Among the bacteria with anti microbial activity Pseudomonas aeroginosa was the most effective on the fusarium solani. In addition, the results obtained from the growth curves of the bacteria indicated that most of the microorganisms produced their compounds at the first 18 hours which was continued up to 72 hrs in some isolates.Discussion and conclusion: The present study showed that soybean plant containing endophytic bacteria had the ability to produce antimicrobial effect against plant pathogens and that the produced compounds can be used in further researches.