title: A novel nonionic surfactant- and solvent-stable alkaline serine protease from Serratia sp. SYBC H with duckweed as nitrogen source: production, purification, characteristics and application.
abstract: A novel nonionic surfactant- and hydrophilic solvent-stable alkaline serine protease was purified from the culture supernatant of Serratia sp. SYBC H with duckweed as nitrogen source. The molecular mass of the purified protease is about 59 kDa as assayed via SDS-PAGE. The protease is highly active over the pH range between 5.0 and 11.0, with the maximum activity at pH 8.0. It is also fairly active over the temperature range between 30 and 80°C, with the maximum activity at 40°C. The protease activity was substantially stimulated by Mn(2+) and Na(+) (5 mM), up to 837.9 and 134.5% at 40°C, respectively. In addition, Mn(2+) enhanced the thermostability of the protease significantly at 60°C. Over 90% of its initial activity remained even after incubating for 60 min at 40°C in 50% (v/v) hydrophilic organic solvents such as DMF, DMSO, acetone and MeOH. The protease retained 81.7, 83.6 and 76.2% of its initial activity in the presence of nonionic surfactants 20% (v/v) Tween 80, 25% (v/v) glycerol and Triton X-100, respectively. The protease is strongly inhibited by PMSF, suggesting that it is a serine protease. Washing experiments revealed that the protease has an excellent ability to remove blood stains.
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Department of Education, Ministry of Education, School of Biotechnology, Jiangnan University, Lihu Road 1800, 214122, Wuxi, Jiangsu Province, China.
authors.forename: G Y
authors.initials: GY
authors.lastname: Li
authors.forename: Y J
authors.initials: YJ
authors.lastname: Cai
authors.forename: X R
authors.initials: XR
authors.lastname: Liao
authors.forename: J
authors.initials: J
authors.lastname: Yin
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D019684:Magnoliopsida / Q000378:metabolism; D008970:Molecular Weight; D009584:Nitrogen / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D057057:Serine Proteases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D012705:Serratia / Q000201:enzymology*; D012997:Solvents / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D011480:Protease Inhibitors; D012997:Solvents; D013501:Surface-Active Agents; D010450:Endopeptidases; D057057:Serine Proteases; C087822:alkaline protease; D009584:Nitrogen