Characterization and Anti-Candida Activity of the Endophytic Streptomyces Isolated from Asystasia gangetica doi.org/10.26538/tjnpr/v5i5.4

Abstract

Oral candidiasis, or oral thrush, is a common fungal infection of the oral cavity caused by the Candida species. This infection can cause oral discomfort, pain, and loss of appetite. Because of the increase in antifungal resistance among Candida species, alternative antifungal compounds are required to be developed. Actinobacteria, specifically the Streptomyces species, are well known as producers of bioactive compounds and play an important role in drug discovery. The endophytic actinobacteria strain 5R010, isolated from the root of Asystasia gangetica, was identified using phenotypic properties and 16S rRNA gene analysis. The spiral spore chains were observed on the aerial mycelia of strain 5R010. LL-diaminopimelic acid was detected in the whole-cell hydrolysate. The strain showed the closest 16S rRNA gene similarity of 99.72% with Streptomyces sioyaensis as well as sharing the same node with sioyaensis in the phylogenetic tree. On the basis of the agar disc diffusion method, the crude ethyl acetate extract of strain 5R010 showed inhibitory activity against seven tested Candida species including Candida albicans TISTR 5554, Candida glabrata TISTR 5006, Candida guilliermondii TISTR 5206, Candida krusei TISTR 5351, Candida parapsilosis TISTR 5007, Candida pseudotropicalis TISTR 5336, and Candida tropicalis TISTR 5268. Based on the results obtained from this study, S. sioyaensis 5R010 can be employed in further research involving the isolation of antifungal agents.