Diversity and antimicrobial activity of culturable actinobacteria isolated from the sediment of Sarıkum Lake

Abstract

In this study, actinobacteria isolated from Sarıkum Lake sediment were characterized (Sinop-Turkey). A total of 48 actinobacteria were isolated using ten selective media with the dilution-plating method. The phylogenetic analysis according to 16S rRNA gene sequencing showed that 40% of the isolated strains belong to the widely distributed genus of Streptomyces, 36% belong to genus of Micromonospora, 24% of the isolates belong to rare genera such as Rhodococcus, Plantactinospora, Nonomuraea, Actinomadura and Streptosporangium. Most of the isolated strains belong to the genus Streptomyces (40%) and two isolates may be new species. All of the isolates were tested for antimicrobial activity; only 12 isolates exhibited antimicrobial activity. Nevertheless, 11 isolates were active against gram-positive, 5 were potential against gram-negative and no isolates had any effect against pathogenic fungi. All of the 48 isolates were analysed for genes encoding nonribosomal peptide synthetases (NRPS) and polyketide synthases (PKS). In all of the 48 isolates were detected NRPS sequences, PKS-I in 28 isolates and PKS-II in 22 isolates. PKS-I – PKS-II – NRPS genes were identified ın 17 isolates.

Keywords:

• Sarıkum
• actinobacteria
• 16S rRNA
• antimicrobial activity
• NRPS
• PKS-I and PKS-II

Acknowledgements

The authors extend our gratitude to Prof. Dr. Nevzat Sahin (Faculty of Art and Science, Department of Molecular Biology and Genetics, Ondokuz Mayıs University) for his contributions to the study.

Disclosure of potential conflicts of interest

There is no conflict between the authors.

Funding

This study was supported by Sinop University Scientific Research Projects Unit (MMF-1901-16-16).

Research involving human participants and/or animals

The research does not involve human participants or animals.

Informed consent

I declare that all data in the study is correct. The work presented has not been published elsewhere.

Data availability

All data that support the findings reported in this study are available from the corresponding author upon reasonable request.