title: Salt-activated endoglucanase of a strain of alkaliphilic Bacillus agaradhaerens.
abstract: An endoglucanase was purified to homogeneity from an alkaline culture broth of a strain isolated from seawater and identified here as Bacillus agaradhaerens JAM-KU023. The molecular mass was around 38-kDa and the N-terminal 19 amino acids of the purified enzyme exhibited 100% sequence identity to Cel5A of B. agaradhaerens DSM8721(T). The enzyme activity increased around 4-fold by the addition of 0.2-2.0 M NaCl in 0.1 M glycine-NaOH buffer (pH 9.0). KCl, Na2SO4, NaBr, NaNO3, CH3COONa, LiCl, NH4NO3, and NH4Cl also activated the enzyme up to 2- to 4-fold. The optimal pH and temperature values were pH 7-9.4 and 60 degrees C with 0.2 M NaCl, but pH 6.5-7 and 50 degrees C without NaCl; enzyme activity increased approximately 6-fold at 60 degrees C with 0.2 M NaCl compared to that at 50 degrees C without NaCl in 0.1 M glycine-NaOH buffer (pH 9.0). The thermostability and pH stability of the enzyme were not affected by NaCl. The enzyme was very stable to several chemical compounds, surfactants and metal ions (except for Fe2+ and Hg2+ ions), regardless whether NaCl was present or not.
authors.affiliation: Extremobiosphere Research Center of Japan Agency for Marine-Earth Science Technology (JAMSTEC), 2-15 Natsushima, Kanagawa, 237-0061, Japan.
authors.forename: Kazumichi
authors.initials: K
authors.lastname: Hirasawa
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Uchimura
authors.forename: Masami
authors.initials: M
authors.lastname: Kashiwa
authors.forename: William D
authors.initials: WD
authors.lastname: Grant
authors.forename: Susumu
authors.initials: S
authors.lastname: Ito
authors.forename: Tohru
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Koki
authors.initials: K
authors.lastname: Horikoshi
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000145:classification / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development; D002480:Cellulase / Q000302:isolation & purification / Q000378:metabolism*; D004269:DNA, Bacterial / Q000032:analysis; D004790:Enzyme Induction; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000494:pharmacology*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; D002480:Cellulase