AUTHOR=Ser Hooi-Leng , Tan Loh Teng-Hern , Palanisamy Uma D. , Abd Malek Sri N. , Yin Wai-Fong , Chan Kok-Gan , Goh Bey-Hing , Lee Learn-Han 

TITLE=Streptomyces antioxidans sp. nov., a Novel Mangrove Soil Actinobacterium with Antioxidative and Neuroprotective Potentials

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.00899

DOI=10.3389/fmicb.2016.00899

ISSN=1664-302X

ABSTRACT=<p>A novel strain, <italic>Streptomyces antioxidans</italic> MUSC 164<sup>T</sup> was recovered from mangrove forest soil located at Tanjung Lumpur, Malaysia. The Gram-positive bacterium forms yellowish-white aerial and brilliant greenish yellow substrate mycelium on ISP 2 agar. A polyphasic approach was used to determine the taxonomy status of strain MUSC 164<sup>T</sup>. The strain showed a spectrum of phylogenetic and chemotaxonomic properties consistent with those of the members of the genus <italic>Streptomyces</italic>. The cell wall peptidoglycan was determined to contain LL-diaminopimelic acid. The predominant menaquinones were identified as MK-9(H<sub>6</sub>) and MK-9(H<sub>8</sub>), while the identified polar lipids consisted of aminolipid, diphosphatidylglycerol, glycolipid, hydroxyphosphatidylethanolamine, phospholipid, phosphatidylinositol, phosphatidylethanolamine, phosphatidylglycerol and lipid. The cell wall sugars consist of galactose, glucose and ribose. The predominant cellular fatty acids (&gt;10.0%) were identified as iso-C<sub>15:</sub><sub>0</sub> (34.8%) and anteiso-C<sub>15:</sub><sub>0</sub>(14.0%). Phylogenetic analysis identified that closely related strains for MUSC 164<sup>T</sup> as <italic>Streptomyces javensis</italic> NBRC 100777<sup>T</sup> (99.6% sequence similarity), <italic>Streptomyces yogyakartensis</italic> NBRC 100779<sup>T</sup> (99.6%) and <italic>Streptomyces violaceusniger</italic> NBRC 13459<sup>T</sup> (99.6%). The DNA–DNA relatedness values between MUSC 164<sup>T</sup> and closely related type strains ranged from 23.8 ± 0.3% to 53.1 ± 4.3%. BOX-PCR fingerprints comparison showed that MUSC 164<sup>T</sup> exhibits a unique DNA profile, with DNA G + C content determined to be 71.6 mol%. Based on the polyphasic study of MUSC 164<sup>T</sup>, it is concluded that this strain represents a novel species, for which the name <italic>Streptomyces antioxidans</italic> sp. nov. is proposed. The type strain is MUSC 164<sup>T</sup> (=DSM 101523<sup>T</sup> = MCCC 1K01590<sup>T</sup>). The extract of MUSC 164<sup>T</sup> showed potent antioxidative and neuroprotective activities against hydrogen peroxide. The chemical analysis of the extract revealed that the strain produces pyrazines and phenolic-related compounds that could explain for the observed bioactivities.</p>