FRESENIUS ENVIRONMENTAL BULLETIN, cilt.16, sa.2, ss.140-144, 2007 (SCI-Expanded)
In this study, we determined the resistance to heavy metals (Zn2+ and Cd2+) and exopolysaccharide (EPS) production by 15 Pseudomonas spp. EPS yields from these strains ranged between 22-192 mg l(-1). In addition, EPS production rates of two strains (G I and G 12), selected on the basis of their high EPS production (192 and 182 mg l(-1), respectively), but also heavy metal resistance, were determined in the presence of Zn2+ (10-40 mM) and Cd2+ (5-20 mM). There was a general increase in EPS production by both strains with increasing heavy metal concentrations. G12 strain showed an increase (approx. 6-fold) in the extent of EPS produced on Pseudomonas Agar P (Difco) medium, supplemented with 2% (v/v) glycerol containing 40 mM Zn2+. By contrast, G1 strain exhibited a lower increase than G12 strain. Furthermore, G12 and G1 strains showed an identical increase (approx. 2-fold) in EPS production on Pseudomonas Agar P (Difco) medium, when supplemented with 2% (v/v) glycerol containing 20 mM Cd2+.