Özet:

A total of 10 actinobacterial strains were isolated from a lichen and an orchid species by employing a selective isolation procedure for actinobacteria. Antimicrobial activities of the isolates were evaluated against Aspergillus niger ATCC 16404, Candida albicans ATCC 10231, Enterococcus faecalis ATCC 29212, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Klebsiella pneumoniae A TCC 700603, Pseudomonas aeruginosa A TCC 27853, Salmonella enterica ATCC 13311, Staphylococcus aureus ATCC 29213 and Listeria monocytogenes NCTC 5348. Out of the 10 isolates, eight showed antimicrobial activity against at least one pathogen. For molecular identification of the strains, 16S rRNA gene sequence analysis was performed. The pairwise comparison of the 16S rRNA gene sequences of the strains with the databases showed that the strains are members of the genus Streptomyces by sharing 98.9 – 100% gene sequence similarities. Phylogenetic relationships of the strains within the genus Streptomyces were revealed by maximum likelihood and maximum parsimony phylogenetic trees. The results revealed that unexplored environmental habitats like lichens and plant tissues may represent a potential reservoir for novel actinobacteria with promising bioactivity features.