Production, optimization and characterization of partially purified anti-mycotic compound from marine soil derived streptomycetes originating at unexplored region of Bay of Bengal, India

Environ Res. 2024 Jun 15;251(Pt 2):118698. doi: 10.1016/j.envres.2024.118698. Epub 2024 Mar 20.

Abstract

Sixty-eight morphologically distinct isolates of marine actinomycetes were derived from seashore, mangrove, and saltpan ecosystems located between the Palk Strait and Gulf of Mannar region, Bay of Bengal, Tamilnadu. Twenty-five (36.8%) isolates exhibited anti-mycotic activity against Candida albicans and Cryptococcus neoformans in preliminary screening, and 4 isolates with prominent activity were identified and designated at the genus level as Streptomyces sp. VPTS3-I, Streptomyces sp. VPTS3-2, Streptomyces sp. VPTSA1-4 and Streptomyces sp. VPTSA1-8. All the potential antagonistic isolates were further characterized with phenotypic and genotypic properties including 16S rRNA gene sequencing and identified species level as Streptomyces afghaniensis VPTS3-1, S. matensis VPTS3-2, S. tuirus VPTSA1-4 and S. griseus VPTSA1-8. In addition, the active fractions from the potential antagonistic streptomycetes were extracted with organic solvents by shake flask culture method and the anti-mycotic efficacies were evaluated. The optimization parameters for the production of the anti-mycotic compound were found to be pH between 7 and 8, the temperature at 30ᵒC, the salinity of 2%, incubation of 9 days, and starch and KNO3 as the suitable carbon and nitrogen sources respectively in starch casein medium.

Keywords: 16S rDNA sequencing; Anti-mycotic activity; Compound characterization; In vitro optimization; Marine streptomycetes.

MeSH terms

  • Antifungal Agents* / pharmacology
  • Bays / microbiology
  • Candida albicans / drug effects
  • Cryptococcus neoformans / drug effects
  • India
  • RNA, Ribosomal, 16S / genetics
  • Soil Microbiology
  • Streptomyces* / genetics
  • Streptomyces* / metabolism

Substances

  • Antifungal Agents
  • RNA, Ribosomal, 16S