Antioxidant Activities of Streptomyces sp. strain MUSC 14 from Mangrove Forest Soil in Malaysia.

Hefa Mangzira Kemung,Kok-Gan Chan,Learn-Han Lee,Hooi-Leng Ser,Loh Teng-Hern Tan,Jodi Woan-Fei Law,Bey-Hing Goh

doi:10.1155/2020/6402607

Abstract

The mangrove ecosystem of Malaysia remains yet to be fully explored for potential microbes that produce biologically active metabolites. In the present study, a mangrove-derived Streptomyces sp. strain MUSC 14 previously isolated from the state of Pahang, Malaysia Peninsula, was studied for its potential in producing antioxidant metabolites. The identity of Streptomyces sp. strain MUSC14 was consistent with the genotypic and phenotypic characteristics of the Streptomyces genus. The antioxidant potential of Streptomyces sp. strain MUSC 14 was determined through screening of its methanolic extract against sets of antioxidant assays. The results were indicative of Streptomyces sp. strain MUSC 14 displaying strong antioxidant activity against ABTS, DPPH free radicals and metal chelating activity of 62.71 ± 3.30%, 24.71 ± 2.22%, and 55.82 ± 2.35%, respectively. The result of ferric reducing activity measured in terms of dose was equivalent to 2.35–2.45 μg of positive control ascorbic acid. Furthermore, there was a high correlation between the total phenolic content and the antioxidant activities with r = 0.979, r = 0.858, and r = 0.983 representing ABTS, DPPH, and metal chelation, respectively. Overall, the present study suggests that Streptomyces sp. strain MUSC 14 from mangrove forest soil has potential to produce antioxidant metabolites that can be further exploited for therapeutic application.

Highlights

Reactive oxygen species (ROS) are free radicals that tend to react with electron rich species at the cellular level in biological system causing cellular damage to their structure and function [1]
Given that previously isolated Streptomyces from mangrove soil have shown promising biological activities including antioxidant activity, this study attempts to investigate the potential of Streptomyces sp. strain MUSC 14 isolated from mangrove soil in Pahang, Peninsular Malaysia
Genomic and Phylogenetic Analysis of Strain MUSC 14. e phylogenetic analysis on the basis of the 16S rRNA led to the identification of strain MUSC 14 (GenBank/EMBL/ DDBJ accession number KF311012) as belonging to the genus Streptomyces (Figure 1) and denoted Streptomyces sp. strain MUSC 14. e phylogenetic tree constructed for strain MUSC 14 on the basis of its 16S rRNA sequence revealed highest gene sequence similarity with Streptomyces bungoensis NBRC 15711T and Streptomyces galbus 40089 DSMT (99.35%) followed by Streptomyces longwoodensis LMG 20096T (99.28%)

Summary

Introduction

Reactive oxygen species (ROS) are free radicals that tend to react with electron rich species at the cellular level in biological system causing cellular damage to their structure and function [1]. E fact that microbial communities in mangrove ecosystem, of soil, remain yet to be studied [25] provides the impetus for drugs discovery research focused on Streptomyces genus. Recent review by Ser et al [23] detailed the potential of Streptomyces from mangrove soil in Malaysia to produce biologically active metabolites with anticancer and antioxidant activities with addition to studies carried out by Kemung et al [10], Tan et al [28,29,30] and Law et al [31]. Given that previously isolated Streptomyces from mangrove soil have shown promising biological activities including antioxidant activity, this study attempts to investigate the potential of Streptomyces sp. The total phenolic content of the methanolic extract was investigated in an attempt to correlate the antioxidant activities with the presence of the phenolic content of the extract

Materials and Methods

Antioxidant Potential of Extract MUSC 14

Results and Discussion

Gallic acida Gallic acidb EDTAc