Endophytic actinomycetes associated with medicinal plants are known as producers of bioactive substances with high commercial value such as antimicrobial, anticancer capabilities. In this study, 78 endophytic actinomycetes were isolated from Cinnamomum loureiri plants collected in Hoa Binh province. Experimental results showed that 16.7 percent of total isolates inhibited the growth of Proteus vulgaris CNLM; the same ratio of 14.1 percent inhibited Escherichia coli ATCC 11105; Sarcina lutea CNLM, Staphylococcus epidemidis ATCC 12228, Candida albicans ATCC 10231; 12.8 percent inhibited Bacillus cereus ATCC 11778 and 1 percent displayed antagonistic activity against Salmonella enterica subsp. enterica serovar Typhimurium ATCC 14028. Among those tested, the isolates HBQI9, HBQ33 showed the highest activity against Staphylococcus epidemidis ATCC 12228, Candida albicans ATCC 10231, respectively. Amplification of genes involved in the biosynthesis of antibiotics including polyketide synthases type I (PKS-I), polyketide synthases type I (PKS-II) va nonribosomal peptide synthetase (NRPS) found that both isolates HBQI9, HBQ33 possessed genes PKS-I, PKS-II and did not have NRPS gene. The description of the morphological, biochemical and physiological properties showed that both isolates HBQ19 and HBQ33 have the spiral chains of spores with the smooth surfaces, no soluble pigments, well-growth at 28-37°C; temperature, pH ranges for growth at 28-37°C, pH 5-11. Besides the ability to utilize different carbon, nitrogen sources, both isolates can synthesize hydrolytic enzymes such as amylase, chitosanase and cellulase. Based on the criteria of International Streptomyces Project (ISP), Bergey's Mannual of Determinative Bacteriology and sequence analysis of gene 16S rDNA, the strains HBQ19 and HBQ33 were classified as Streptomyces ahgustmyceticus HBQ19, Streptomyces graminisoli HBQ33, respectively.
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