Isolation, screening and identification of microorganisms having antimicrobial activity and causing cytotoxicity isolated from sediment samples of the Vung Ang bay in Ha Tinh

Actinomycetes has been extensively studied due to its ability produce secondary compounds with high application value. Especially their antibiotic ability, more than 40% of antibiotics are derived from actinomycetes which genus Streptomyces predominates. Moreover, marine have being great interest in recent years bioactive substances capable providing diverse and novel chemical structures. In this study, 8 samples sediments collected Vung Ang bay Ha Tinh provinces, we isolated 20 strains actinomycetes. The were fermented A1+ medium, the fermentation fluid was extracted 5 times ethyl acetate, recovered sediment determined antibacterial cytotoxic activity. From screening results, two highest activity cytotoxicity selected ie., HT03 HT06. Both had antagonistic Enterococcus faecalis ATCC29212 MICHT03= 32 μg/mL, MICHT06= 16μg/mL, Stapphylococus aureus ATCC25923 64 μg/mL Bacillus cereus ATCC 13245 same MIC = 16 μg / mL. addition, HT06 able strongly inhibit yeast Candida albicans ATCC10231 μg/mL. Especially, strains, HT06, exhibited very good toxicity on all cancer cell lines (MCF-7 breast cell; MDA-MB-231 lung cell). NCI-H1975; HeLa cervical AGS gastric cell) at both test concentrations 30 µg/mL 100µg/mL. By analysis 16S rRNA sequence, results showed that strain similarity (99.93%) fradiaes fradiae ATCC. defined belong Nocardiopsis synnemataformans sequence identity 99.89% Japanese standard DSM 44143 NBRC-102581.