Characterization of three bacterial strains- biodegradants of aromatic substrates

Three bacterial strains, isolated from contaminated soil, were adapted to degrade increasing concentrations of xenobioticaromatic substrates. Morphological, physiological and biochemical characteristics define them as belonging to the genera Pseudomonas, Alcaligenes and Citrobacter. The strain with highest biodegradative activity is taxonomically related as the closest to Pseudomonas pseudoalcaligenes

EXTRA- AND INTRACELLULAR ESTERASES INVOLVED IN DIMETHYLTEREPHTHALATE CATABOLISM BY PSEUDOMONAS SP.

The strain Pseudomonas sp. 054, isolated previously from polluted soil, possesses a high biodegrading activity towards the aromatic ester dimethylterephthalate. The ester hydrolyzing activity of the strain was investigated. Two types of esterases, extra- and intracellular, were detected after growth in liquid medium. The enzyme activities were proved in the culture supernatant and in the crude cell extract by the use of a native electrophoresis. The extracellular protein with an esterase activity had a molecular weight of 67 kDa, while the intracellular fraction produced four separate bands with ester hydrolyzing activity

Characterization of three bacterial strains- biodegradants of aromatic substrates

Three bacterial strains, isolated from contaminated soil, were adapted to degrade increasing concentrations of xenobioticaromatic substrates. Morphological, physiological and biochemical characteristics define them as belonging to the genera Pseudomonas, Alcaligenes and Citrobacter. The strain with highest biodegradative activity is taxonomically related as the closest to Pseudomonas pseudoalcaligenes  

DEGRADATION OF DIMETHYLTEREPHTHALATE BY NATURALLY FORMED MICROBIAL ASSOCIATIONS 169AC AND 189AC

Mixed microbial cultures, naturally combined in two-member associations (169AC and 189AC), actively degraded the aromatic ester dimethylterephthalate as a single source of carbon and energy. The biodegrading activity of the associations and also of the pure culture combination was tested under polysubstrate conditions. When complementary substrates like methanol, xylol and ethylene glycol were added, the consisting of a bacterial and an actinomyces strains association 189, exhibited a higher activity. A biomass of this association was brought to freeze-drying and the lyophilizate saved biodegrading activity towards the studied substrate

DIMETHYLTEREPHTHALATE CATABOLISM BY PSEUDOMONAS SP.

Pseudomonas sp. strain 054 isolated from polluted soil utilizes dimethylterephthalate (DMT) as a sole carbon and energy source. The degradation of this compound starts with a two-stage hydrolysis of the ester bonds to monomethylterephthalate and terephthalic acid. In the meta-pathway for cleavage of the aromatic ring the latter is metabolized to protocatechuate. The induction of the ester hydrolysis is slightly specific, while the oxygenase mechanism is induced by substrates with aromatic structure

DIMETHYLTEREPHTHALATE CATABOLISM BY PSEUDOMONAS SP.

Pseudomonas sp. strain 054 isolated from polluted soil utilizes dimethylterephthalate (DMT) as a sole carbon and energy source. The degradation of this compound starts with a two-stage hydrolysis of the ester bonds to monomethylterephthalate and terephthalic acid. In the meta-pathway for cleavage of the aromatic ring the latter is metabolized to protocatechuate. The induction of the ester hydrolysis is slightly specific, while the oxygenase mechanism is induced by substrates with aromatic structure

DEGRADATION OF DIMETHYLTEREPHTHALATE BY NATURALLY FORMED MICROBIAL ASSOCIATIONS 169AC AND 189AC

Mixed microbial cultures, naturally combined in two-member associations (169AC and 189AC), actively degraded the aromatic ester dimethylterephthalate as a single source of carbon and energy. The biodegrading activity of the associations and also of the pure culture combination was tested under polysubstrate conditions. When complementary substrates like methanol, xylol and ethylene glycol were added, the consisting of a bacterial and an actinomyces strains association 189, exhibited a higher activity. A biomass of this association was brought to freeze-drying and the lyophilizate saved biodegrading activity towards the studied substrate

MICROBIAL CULTURE ADAPTATION TO BIODEGRADATION OF DIMETHYLTEREPHTHALATE

Forty-five microbial cultures have been isolated from a chemically polluted region, using dimethylterephthalate (DMT) as a sole carbon and energy source. They have been subjected to adaptive selection in order to increase their biodegradative potential. The gradual increase of the xenobiotic substrate concentration from 2.5 to 25 mM induced adaptive changes in the tested strains. 20% of the studied strains showed a high biodegradative activity towards DMT and the best adaptation was expressed by the soil microorganisms

IDENTIFICATION OF LACTIC ACID BACTERIA ISOLATED FROM KATYK, GOAT’S MILK AND CHEESE

Eighteen lactic acid bacterial strains were isolated from home made katyk, goat's milk and cheese. Nine of them belonged to lactic acid cocci and others were referred to genus Lactobacillus. Five strains were identified to species by determination of morphological, cultural, physiological and biochemical characteristics - Pediococcus acidilactici, Pediococcus pentosaceus, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus helveticus and Lactobacillus plantarum

MICROBIAL CULTURE ADAPTATION TO BIODEGRADATION OF DIMETHYLTEREPHTHALATE

Forty-five microbial cultures have been isolated from a chemically polluted region, using dimethylterephthalate (DMT) as a sole carbon and energy source. They have been subjected to adaptive selection in order to increase their biodegradative potential. The gradual increase of the xenobiotic substrate concentration from 2.5 to 25 mM induced adaptive changes in the tested strains. 20% of the studied strains showed a high biodegradative activity towards DMT and the best adaptation was expressed by the soil microorganisms