_____________________________________________________________________________________________________ *Corresponding author: E-mail: ifyjey@yahoo.com; Microbiology Research Journal International 29(5): 1-9, 2019; Article no.MRJI.52376 ISSN: 2456-7043 (Past name: British Microbiology Research Journal, Past ISSN: 2231-0886, NLM ID: 101608140) Isolation, Screening and Characterization of Exopolysaccharide Producing Bacteria I. G. Nwosu 1* , G. O. Abu 1 and K. O. Agwa 1 1 Department of Microbiology, World Bank Africa Centre of Excellence for Oilfield Chemical Research, University of Port Harcourt, Rivers State, Nigeria. Authors’ contributions This work was carried out in collaboration among all authors. All authors read and approved the final manuscript. Article Information DOI: 10.9734/MRJI/2019/v29i530174 Editor(s): (1) Dr. Ana Claudia Correia Coelho, Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro, Portugal. (2) Dr. Juliano de dea lindner, Professor, Department of Food Science and Technology, Federal University of Santa Catarina (UFSC), Brazil. Reviewers: (1) S.Mahendran, Ayya Nadar Janaki Ammal College, India. (2) Yemisi Ajoke Olawore, National mathematical Centre, Nigeria. (3) J. Francis Borgio, India. Complete Peer review History: http://www.sdiarticle4.com/review-history/52376 Received 28 July 2019 Accepted 31 October 2019 Published 16 November 2019 ABSTRACT 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 Original Research Article