Open AccessIsolation, Screening and Characterization of Exopolysaccharide Producing Bacteria
Author(s) -
I. G. Nwosu,
Gideon O. Abu,
K. O. Agwa
Publication year - 2019
Publication title -
microbiology research journal international
Language(s) - English
Resource type - Journals
ISSN - 2456-7043
DOI - 10.9734/mrji/2019/v29i530174
Subject(s) - isolation (microbiology) , bacteria , agar , food science , 16s ribosomal rna , biology , microorganism , extreme environment , microbiology and biotechnology , bacillus (shape) , agar plate , genetics
Exopolysaccharides(EPSs) are essential metabolites synthesized and excreted by certain microorganisms in response to extreme condition of pH, temperature, salinity, osmotic stress and other contaminants for survival in such adverse environment. The present study focuses on isolation of exopolysaccharide producing bacteria from extreme environment of oil polluted soil of Ogoni land and marine water of Bonny Island. Screening of EPS producing abilities of the selected isolates were estimated using two approaches viz gravimetric analysis of EPS dry weight and quantification assay for total carbohydrate content by phenol sulphuric acid method. Result revealed that a total of forty (40) different colonies were suspected to produce exopolysaccharide after preliminary screening by selecting thick ropy-like colony formers on agar medium. Secondary screening indicated that twelve (12) isolates produced precipitates above 1000mg/l of total dry weight and eight (8) isolates produced highest EPS yield above 1000mg/l of culture media with carbohydrate content determination. Five isolates with the code WAS1, WAS11, SC6, SOS7 and SOS10 produced significantly higher EPS compared to other bacterial colonies isolated and were termed as most potent EPS producers. These isolates were identified based on 16S rDNA sequence as Providencia stuarti, Escherichia coli, Shewanella chilikensis and Bacillus nealsonii. The result of the present study indicated that these strains have the potentials of producing high exopolysaccharides and can be explored in biotechnological industries.