Characterization and Structure Elucidation of Antibacterial Compound of Streptomyces sp. ECR77 Isolated from East Coast of India

Abstract

Forty marine actinobacteria were isolated from the sediments of east coast (Bay of Bengal) region of Tamilnadu, India. Morphologically distinct colonies were primarily tested against fish pathogenic bacteria such as Vibrio cholerae, V. parahaemolyticus, V. alginolyticus, Pseudomonas fluorescens and Aeromonas hydrophila by cross-streak plate method. The secondary metabolites produced by the highly potential strain cultured on starch casein broth were extracted separately with various solvents such as alcohol, ethyl acetate, methanol, petroleum ether and chloroform. The antibacterial assay of the bioactive compounds was tested against the fish pathogenic bacteria by well diffusion method. Of the various solvents used, the ethyl acetate extract of the isolate had good antibacterial activity. The potential strain was identified as Streptomyces labedae by phenotypic, 16S rRNA gene sequence and phylogenetic analysis. Purification of the biologically active compounds by column chromatography led to isolation of 27 fractions. The biologically active fraction was re-chromatographed on a silica gel column to obtain a single active compound, namely N-isopentyltridecanamide. The structure of the compounds was elucidated on the basis of ultra violet, Fourier transform infrared and nuclear magnetic resonance spectra.

Antagonistic activity of terrestrial <i>Streptomyces</i> sp. VITNK9 against Gram negative bacterial pathogens affecting the fish and shellfish in aquaculture

“…and designated as Streptomyces sp. VITNK9 on the basis of the molecular taxonomic characterization (Thirumurugan & Vijayakumar 2015, Augustine et al 2016, Jenifer et al 2018.…”

Microbial Proteases Applications

“…Extracellular serine proteases A and B are secreted by an organism, Streptomyces griseus , used for commercial production of pronase. The genes encoding protease A (sprA) and protease B (sprB) were isolated from the S. griseus genomic library, and their proteolytic activity was demonstrated in Streptomyces lividans (Henderson et al, 1987; Ramesh et al, 2009; Thirumurugan and Vijayakumar, 2015). Each enzyme is initially secreted as a precursor as suggested by the DNA sequences, which is then incorporated to remove N-terminal propeptide from the mature protease.…”

Marine natural products

“…72 A number of other compounds of lower molecular weight were also isolated from actinomyctes or Streptomyces spp. These included two butenolides 92 and 93, 73 four cycloheximide derivatives 94-97, 74 a furanone 98, 75 an a-pyrone 99, 76 four benzothioate glycosides 100-103, 77 an alkylamide 104, 78 an aniline derivative 105 with algicidal properties 79 and an incompletely characterized cyslabdan-like compound 106. 80 Anti-dormant mycobacterial properties were reported for the known terrestrial antibiotic nybomycin 81 isolated, in this instance, from a marine Streptomycete.…”