African Journal of Biotechnology Vol. 6 (9), pp. 1115-1121, 2 May 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Analysis of bacterial strains from contaminated and non-contaminated sites for the production of biopolymers

M. Usman Arshad, Nazia Jamil^*, Nighat Naheed and Shahida Hasnain

Department of Microbiology and Molecular Genetics, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, Pakistan.

*Corresponding author. E-mail: jamil_nazi@yahoo.com.

Accepted 21 February, 2007

A total 18 strains were collected from non-contaminated and contaminated environments, and were purified. All purified strains were characterized for Gram reaction and biochemical analysis. Screening for bioplastic production was done by Sudan black staining. Strains isolated from non-contaminated sites showed no polyhydroxyalkanoate (PHA) production. Biochemical analysis showed that PHA producing strains belong to Pseudomonas, Citrobacter, Enterobacter, Klebsiella, Escherichia and Bacillus genera.  PHA extraction was done by sodium hypochlorite digestion method. Strain MS2D showed maximum percentage (65%). Production of PHA was optimized for different temperatures and pH. Selected strains were also tested for exopolysaccharides (EPS) production on EPS detection medium by solvent precipitation method. Four out of nine strains exhibited EPS production ability. EPS production was also optimized for different temperatures and pH.

Key words:  Biopolymer, bioplastic, exopolysaccharides, contaminated environment.