SECONDARY BIOACTIVE METABOLITE GENE CLUSTERS IDENTIFICATION OF ANTICANDIDA-PRODUCING Streptomyces Sp. GMR22 ISOLATED FROM WANAGAMA FOREST AS REVEALED BY GENOME MINING APPROACH

Abstract

Streptomyces are a group of Gram-positive bacteria belonging to the Actinobacteria class, which are among the most important bacteria for producing secondary bioactive metabolites such as antibiotics, chemotherapeutics, insecticides and other high-value chemicals. Genome mining of gene clusters that encode the biosynthetic pathways for these metabolites has become a key methodology for novel compound discovery. Recently, we have isolated the Streptomyces sp. GMR22 from Cajuput rhizospheric soil at Wanagama Forest, Indonesia. GMR22 produced a secondary metabolite that inhibited Candida albicans with IC 50 of 62.5μg/mL. The objective of this work was to reveal the novel secondary metabolites from GMR22 by genome mining approach. The antiSMASH 3.0 was used to predict gene clusters that encode the biosynthetic pathways of secondary metabolites in the genome of GMR22, and their core chemical structures. The phylogenomic analysis showed that GMR22 was closely related to Streptomyces bingchenggensis BCW1, as well as to the large genome size (9.5-12.7Mbp) groups of Streptomyces. AntiSMASH 3.0 analysis revealed that the genome of Streptomyces sp. GMR22 harbored at least 63 gene clusters that encode the biosynthetic pathways of secondary metabolites. It was the highest number of gene clusters had been observed among the members of Streptomyces groups, with polyketide synthetase (PKS) was predicted as the major groups of the identified gene cluster products. The results suggested that GMR22 could be a strong potential candidate for secondary bioactive metabolites source.

Antarctic Streptomyces fildesensis So13.3 strain as a promising source for antimicrobials discovery

“…All previous types have been studied for their antimicrobial potential, but particularly non‒ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS I and II) pathways, which are thought to be responsible for antibiotic synthesis in actinobacteria 63 . The number of BGCs of secondary metabolites observed is higher than the average usually reported for other mesophilic Streptomyces strains, with ranges from 20 to 30 gene clusters 62,64,65 , with exceptions such as Streptomyces strains isolated from Indonesia 66 and China 67 , which had more than 50 clusters for secondary metabolites. As suggested for Antarctic Pseudoalteromonas strains ‒with a maximum of 19 biosynthetic gene clusters‒ 16 , it have been thought that a greater number of secondary metabolites could be driven by the adaptation and evolution of Streptomyces strains to survive and proliferate under harsh Antarctic conditions.…”

Streptomyces monashensis sp. nov., a novel mangrove soil actinobacterium from East Malaysia with antioxidative potential

“…Meanwhile, the genomic studies of Streptomyces provide a basis for better understanding of the secondary metabolism and the production of target bioactive metabolites, thus creating an opportunity to obtain novel bioactive compounds 86,87 . With the availability of NGS technology, the whole genome of strain MUSC 1J T was subjected to sequencing.…”

Genome Mining Revealed a High Biosynthetic Potential for Antifungal Streptomyces sp. S-2 Isolated from Black Soot

“…To the best of our knowledge, only two strains with a higher number of BGCs than S-2 have been described: S. griseochromogenes ATCC-14511 [13] and Streptomyces sp. GMR22 [64], with 59 and 63 BGCs respectively. However, those analyses were performed with an older version of the anti-SMASH database.…”