Actinobacteria is found to have a potent metabolic activity against pathogens. A new study, published in the journal  Marine Drugs, secondary metabolites of actinobacteria isolated from Indian marine mangrove sediments shows significant antifungal activity against Candida albicans.

The present study led by researchers from VIT University, India in collaboration with researchers from the University of Porto, Portugal reveals the assessment of potent antifungal secondary metabolites from actinobacteria isolated from Indian marine mangrove sediments.

The researchers collected the samples from the coastal regions of Muthupet, Andaman, and the Nicobar Islands. Identification was carried out using 16S rRNA analysis. Later they screened  biosynthetic genes (Polyketide synthase type I / II and Non-ribosomal peptide synthase). 

Actinobacteria were assayed for their antifungal activity against 16 clinical  Candida albicans  and the compound analysis was performed using gas chromatography-mass spectrometry (GC-MS).

The 31 actinobacterial strains were isolated and 16S rRNA gene sequencing revealed that this ecosystem is rich on actinobacteria, with  Streptomyces  as the predominant genus.

The PCR based screening of biosynthetic genes revealed the presence of PKS-I in six strains, PKS-II in four strains and NRPS in 11 strains.

The isolated actinobacteria VITGAP240 and VITGAP241 (two isolates) were found to have a potential antifungal activity against all the tested  C. albicans .

GC-MS results revealed that the actinobacterial compounds were belonging to heterocyclic, polyketides and peptides.

"Overall, the strains possess a wide spectrum of antifungal properties which yields the production of significant bioactive metabolites as potential antibiotics," the authors concluded.