نوع مقاله : پژوهشی- انگلیسی
نویسندگان
دانشکده علوم زیستی، دانشگاه آزاد اسلامی واحد فلاورجان، فلاورجان، اصفهان، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Recently, serious infectious bacteria have become resistant to common antibiotics. On the other hand, heat-tolerant actinobacteria have been less studied for their ability to produce antimicrobial compounds. The present study aimed to isolate actinobacteria from biocompost and to investigate their antimicrobial and anticancer effects. AIA (actinomycete isolation agar), SCA (starch casein agar), and CSPY-ME (casein starch peptone yeast extract malt extract agar) culture media were utilized for the isolation of actinomycetes. The antimicrobial activity was evaluated using cross-streak method. The isolate exhibiting strongest antimicrobial activity was chosen for secondary screening and evaluation of its inhibitory activity against Escherichia coli and MRSA, as well as HepG2 cancer cells. Thin-layer chromatography and UV-visible methods were employed to confirm the presence of the extracted bioactive metabolites. A total of 14 actinomycetes isolates were identified. The isolate RMB exhibited a broader spectrum antimicrobial activity in primary screening against clinical microorganisms including E. coli ATCC 1399, E. coli ATCC 10536, Klebsiella pneumonia ATCC 10031, Pseudomonas aeruginosa PTCC 1310, Staphylococcus aureus ATCC 9144, MRSA ATCC 43300, Candida albicans ATCC 10231, and Fusarium oxysporum SBAN-IAUF-10. The isolate RMB was molecularly identified as Streptomyces thermogriseus strain RMB-IAUF-1. MIC levels of bioactive metabolite extracted from this strain were 60 μg/mL and 80 μg/mL against E. coli and MRSA, respectively. The cell viability in the presence of bioactive metabolite was reached the lowest level at a concentration of 150 μg/mL after both 24 hours (7.5%) and 48 hours (6%), compared to the positive control (22% and 30% at 24 and 48 hours, respectively). The broad-spectrum antimicrobial activity of the isolated Streptomyces thermogriseus RMB-IAUF-1and the dose-dependent cytotoxic effect of its extracted metabolite against HepG2 cancer cells is a promising opportunity for developing innovative therapeutic agents. Further purification and structural characterization of the bioactive compounds are recommended as the next steps.
کلیدواژهها [English]
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