DISTRIBUTION AND ANTIMICROBIAL ACTIVITY OF ENDOPHYTIC ACTINOMYCETES ISOLATED FROM Litsea cubeba (Lour.) Pers. IN NORTHERN PROVINCES OF VIETNAM

Abstract

Endophytic actinomycetes from medicinal plants have been recently reported as the potential producers of antibiotics, anticancer agents and other bioactive compounds. In this study, the distribution and antimicrobial activity of endophytic actinomycetes isolated from Listea cubeba (Lour.) Pers. were investigated. Consequently, the antimicrobial activities of endophytic isolates against eight pathogens, consisting of Salmonella enterica ATCC 14028, Escherichia coli ATCC 11105, Sarcina lutea CNLM, Bacillus cereus ATCC 11778, Proteus vulgaris CNLM, Pseudomonas aeruginosa CNLM, Staphylococcus epidermidis ATCC 12228, Enterobacter aerogenes ATCC 13048 were tested. Total 143 actinomycetes strains were isolated from L. cubeba tissues, in which 53, 23 and 67 strains were respectively obtained from plant samples collected in Thanh Hoa, Hanoi and Phu Tho provinces. Among media used for isolation, the highest number endophytes were from two main media including HV (18.2 %) and SA (16.1 %). Assessment of strains isolated from three kinds of plant tissues, most of endophytes were from roots (n = 65, 45.5 %) and followed by stems (n = 41, 28.7 %) and leaves (n = 37, 25.9 %). Examination of antimicrobial activity of endophytes revealed that 32.9  % of total strains showed inhibitory activity against at least one of the eight tested pathogenic microorganisms. The obtained results indicated that the L. cubeba (Lour.) Pers. could be an extremely rich reservoir for isolation of diverse actinobacteria producing antimicrobial activities and other bioactive compounds.