title: A novel poly(3-hydroxybutyrate)-degrading Streptoverticillium kashmirense AF1 isolated from soil and purification of PHB-depolymerase.
abstract: A new bacterial strain, capable of degrading poly(3-hydroxybutyrate) (PHB) was isolated from soil. This organism, identified as Streptoverticillium kashmirense AF1, secreted PHB depolymerases both on solid as well as in liquid mineral salt medium containing poly(3-hydroxybutyrate) as sole carbon source. The optimum production of PHB depolymerase was observed at pH 8 and 7, at 45 degrees C, 1% substrate concentration and in the presence of lactose as an additional carbon source. The extracellular PHB depolymerase was purified by gel permeation chromatography using Sephadex G-75. The Streptoverticillium kashmirense AF1 produced two types of PHB depolymerases having molecular weights of about 37 and 45 kDa as determined by SDS-PAGE. The difference in dry cell mass and amount of CO2 evolved in the test and control calculated gravimetrically through Sturm test indicated the degradative capabilities of Streptoverticillium kashmirense AF1.
authors.affiliation: Department of Microbiology, Quaid-i-Azam University, Islamabad, Pakistan. alishah_75@yahoo.com
authors.forename: A A
authors.initials: AA
authors.lastname: Shah
authors.forename: Fariha
authors.initials: F
authors.lastname: Hasan
authors.forename: A
authors.initials: A
authors.lastname: Hameed
authors.forename: Safia
authors.initials: S
authors.lastname: Ahmed
mesh_terms: D001673:Biodegradation, Environmental; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D004785:Environmental Pollutants / Q000378:metabolism*; D006885:Hydroxybutyrates / Q000378:metabolism*; D008970:Molecular Weight; D011091:Polyesters / Q000378:metabolism*; D012988:Soil Microbiology; D013302:Streptomyces / Q000302:isolation & purification / Q000378:metabolism*; D000094122:Polyhydroxybutyrates
chemical_list: D002265:Carboxylic Ester Hydrolases; D004785:Environmental Pollutants; D006885:Hydroxybutyrates; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates; C022417:poly-beta-hydroxybutyrate depolymerase