title: Isolation of a psychrotrophic Azospirillum sp. and characterization of its extracellular protease.
abstract: A novel psychrotrophic bacterium secreting a protease was isolated from a mountain soil in Korea. On the basis of a 16S rDNA sequence analysis and physiological properties, the isolate was identified as an Azospirillum sp. The protease purified from the culture supernatant was a monomer in its native form with an apparent molecular mass of 48.6 kDa on SDS-PAGE. The protease was active in a broad pH range around 8.5 and at temperatures up to 40 degrees C and stable at temperatures below 30 degrees C for 3 days. The proteolytic activity was inhibited by iodoacetamide and EDTA. The Mg2+ ion did not activate the enzyme much but reversed the inhibition by EDTA, suggesting that the protease belongs to a cysteine protease stabilized by the Mg2+ ion.
authors.affiliation: Department of Microbiology, Inje University, South Korea.
authors.forename: K H
authors.initials: KH
authors.lastname: Oh
authors.forename: C S
authors.initials: CS
authors.lastname: Seong
authors.forename: S W
authors.initials: SW
authors.lastname: Lee
authors.forename: O S
authors.initials: OS
authors.lastname: Kwon
authors.forename: Y S
authors.initials: YS
authors.lastname: Park
mesh_terms: D016949:Azospirillum / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification; D015373:Bacterial Typing Techniques; D003080:Cold Temperature; D010450:Endopeptidases / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology
chemical_list: D012336:RNA, Ribosomal, 16S; D010450:Endopeptidases