Relationship between heavy metals resistance and exopolysaccharide (EPS) synthesis of Pseudomonas spp. strains

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+

Characterization and production of the exopolysaccharide (EPS) from Pseudomonas aeruginosa G1 and Pseudomonas putida G12 strains

In this study, exopolysaccharides (EPSs) production was investigated by growing strains of Pseudomonas aeruginosa G1 and Pseudomonas putida G12 in medium containing various carbon sources such as glucose, mannose, fructose, and xylose. EPS production (192 and 182 mg/L, respectively) of these strains grown in PAP medium with 2% glycerol (v/v) was used as control. The highest EPS production of the two strains was found in the xylose containing medium. The effect of different concentrations [2-6% (w/v)] of xylose on EPS production of both strains was also studied. The maximum EPS yield (368 mg/l(-1)) of the strain G1 was recorded in 3% (w/v) xylose, while the highest yield EPS yield (262 mg/L(-1)) of the strain G 12 was recorded in 2% (w/v) xylose. The monosaccharide compositions of EPS produced by the two strains were analyzed by HPLC. Strain G1 [2% (w/v) glycerol] was found to compose of neutral sugars (92.0%), acetylated amino sugars (8.0%), while strain G1 [3% (w/v) xylose] contained neutral sugars (99.2%), acetylated amino sugars (0.8%). However, the composition of strain G12 [2% (w/v) glycerol] was neutral sugars (96.8%), acetylated amino sugars (3.2%) and the strain G12 [2% (w/v) xylose] was found to contain neutral sugars (96.1%), acetylated amino sugars (3.9%). (C) 2007 Elsevier Ltd. All rights reserved

Determination of poly-B-hydroxybutyrate (PHB) production in different media by Pseudomonas cepacia G13 strain

WOS: 000232889800016In this study, Poly-beta-hydroxybutyrate (PHB) accumulation was investigated in Pseudomonas cepacia G13 strain. Determination of the amount of PHB was performed chemically. The yield of PHB produced by the A cepacia G13 strain according to dry cell weight was 67.37% w/w. P. cepacia G13 was examined for PHB production in different carbon and nitrogen sources. The amount of PHB produced by this strain in these medium were lower than the amount of PHB production in nutrient broth medium

Dairy propionibacterium strains with potential as biopreservatives against foodborne pathogens and their tolerance-resistance properties

In this study, the thirty-two investigated Propionibacterium spp. strains were examined for their abilities to survive at pH 2.0, 3.0, 4.0 and 5.0 and in the presence of 0.06, 0.15 and 0.30 % bile salts, their influence on the growth of pathogens, as well as their sensitivity against eleven selected antibiotics. P. freudenreichii subsp. freudenreichii IT4, IT16, and P. jensenii MP12, BSM8 and DY1 strains survived in both the acidic and bile salt environments. Among thirty-two tested Propionibacterium spp. strains, five strains demonstrated strong and broad inhibitory spectrum against pathogen strains, and all of the Propionibacterium spp. strains strongly inhibited growth of the Escherichia coli ATCC 11229. Propionibacterium spp. strains demonstrated resistance to streptomycin, gentamycin, kanamycin, rifampicin and polymyxin B antibiotics. Overall, Propionibacterium spp. strains showed high antibacterial activity, tolerance to pH 4.0 and 5.0 and high tolerance to bile salts and will present an alternative source to Lactobacillus and Bifidobacterium for future probiotic development. In addition, culture metabolites of these strains may be used as a preservative in the food industry for the replacement of or reduction in the increasing use of chemical additives. © 2013 Springer-Verlag Berlin Heidelberg.Acknowledgments This research was supported by The Scientific and Technological Research Council of Turkey, through project no. TBAG-(107T486). The authors thank University of Aksaray, Foreign Languages Department, Academic Support Group for Foreign Languages, for proofreading the manuscript