title: Isolation and characterization of a serine protease-producing marine bacterium Marinomonas arctica PT-1.
abstract: A serine protease-producing marine bacterial strain named as PT-1 was isolated and identified as a family of Marinomonas arctica, based on molecular characterization of 16S rRNA gene sequence, phylogenetic tree, and fatty acid composition analyses. Optimized culture conditions for growth of the bacterium PT-1 and production of protease (ProA) were determined to be pH 8.0 in the presence of 5 % NaCl, at 37 °C during 24 h of incubation in the presence of 1.0 % skim milk. The molecular weight of the purified ProA was estimated to be 63-kDa as a major band by SDS-PAGE. We were intrigued to find that the activity of ProA was not inhibited by pepstatin A, chymostatin, and leupeptin known as inhibitors for cysteine protease. However, phenylmethylsulfonyl fluoride (PMSF) completely inhibited protease activity, suggesting that the ProA is like a serine protease. To the best of our knowledge, this is the first report on serine protease of Marinomonas species.
authors.affiliation: Department of Life Sciences, Gachon University, Seongnamdaero 1342, Seongnam-Si, Gyeonggi-do, 461-701, South Korea.
authors.forename: Ah Young
authors.initials: AY
authors.lastname: Yoo
authors.affiliation: Department of Life Sciences, Gachon University, Seongnamdaero 1342, Seongnam-Si, Gyeonggi-do, 461-701, South Korea. jkpark@gachon.ac.kr.
authors.forename: Jae Kweon
authors.initials: JK
authors.lastname: Park
mesh_terms: D059001:Aquatic Organisms / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D053544:Marinomonas / Q000201:enzymology* / Q000235:genetics; D057057:Serine Proteases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D001426:Bacterial Proteins; D057057:Serine Proteases
keywords: Marine bacterium; Marinomonas species; Serine protease; Substrate specificity