title: Purification and biochemical characterization of an alkaline protease from marine bacteria Pseudoalteromonas sp. 129-1.
abstract: An extracellular alkaline protease produced by marine bacteria strain Pseudoalteromonas sp. 129-1 was purified by ammonium sulphate precipitation, anion exchange chromatography, and gel filtration. The purity of the protease was confirmed by SDS-PAGE and molecular mass was estimated to be 35 kDa. The protease maintained considerable activity and stability at a wide temperature range of 10-60 °C and pH range of 6-11, and optimum activity was detected at temperature of 50 °C and pH of 8. Metallo-protease inhibitor, EDTA, had no inhibitory effect on protease activity even at concentration up to 15 mM, whereas 15 mM PMSF, a common serine protease inhibitor, greatly inactivated the protease. The high stability of the protease in the presence of surfactants (SDS, Tween 80, and Triton X-100), oxidizing agent H(2)O(2), and commercial detergents was observed. Moreover, the protease was tolerant to most of the tested organic solvents, and saline tolerant up to 30%. Interestingly, biofilm of Pseudomonas aeruginosa PAO1 was greatly reduced by 0.01 mg ml(-1) of the protease, and nearly completely abolished with the concentration of 1 mg ml(-1). Collectively, the protease showed valuable feathers as an additive in laundry detergent and non-toxic anti-biofilm agent.
authors.affiliation: Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Shimei
authors.initials: S
authors.lastname: Wu
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Liu
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Dechao
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Chaoxu
authors.initials: C
authors.lastname: Li
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
authors.forename: Chaomin
authors.initials: C
authors.lastname: Sun
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D018441:Biofilms / Q000254:growth & development; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000737:chemistry* / Q000302:isolation & purification*; D004789:Enzyme Activation; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D031161:Pseudoalteromonas / Q000201:enzymology* / Q000302:isolation & purification / Q000502:physiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012997:Solvents / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry; D014871:Water Microbiology
chemical_list: D001426:Bacterial Proteins; D012997:Solvents; D013501:Surface-Active Agents; D010450:Endopeptidases; C087822:alkaline protease
keywords: Alkaline protease; Biofilm; Pseudoalteromonas; Purification; Surfactant