A novel species of alkaliphilic Bacillus that produces an oxidatively stable alkaline serine protease.
A novel gram-positive, strictly aerobic, motile, sporulating, and facultatively alkaliphilic bacterium designated KSM-KP43 was isolated from a sample of soil. The results of 16S rRNA sequence analysis placed this bacterium in a cluster with Bacillus halmapalus. However, the level of the DNA-DNA hybridization of KSM-KP43 with B. halmapalus was less than 25%. Moreover, the G + C contents of the genomic DNA were 41.6 mol% for KSM-KP43 and 38.6 mol% for B. halmapalus. Because there were also differences in physiological properties and cellular fatty acid composition between the two organisms, we propose KSM-KP43 as a novel species of alkaliphilic Bacillus. This novel strain produces a new class of protease, an oxidatively stable serine protease that is suitable for use in bleach-based detergents. The enzyme contained 640 amino acid residues, including a possible approximately 200-amino-acid prepropeptide in the N-terminal and a unique stretch of approximately 160 amino acids in the C-terminal regions (434-amino-acid mature enzyme with a calculated molecular mass of 45,301 Da). The C-terminal half after the putative catalytic Ser255 and the contiguous C-terminal extension shared local similarity to internal segments of a membrane-associated serine protease of a marine microbial assemblage and the serine protease/ABC transporter precursors of the slime mold Dictyostelium discoideum, and to the C-terminal half of a cold-active alkaline serine protease of a psychrotrophic Shewanella strain.
Saeki
Katsuhisa
K
Tochigi Research Laboratories of Kao Corporation, Japan.
Hitomi
Jun
J
Okuda
Mitsuyoshi
M
Hatada
Yuji
Y
Kageyama
Yasushi
Y
Takaiwa
Mikio
M
Kubota
Hiromi
H
Hagihara
Hiroshi
H
Kobayashi
Tohru
T
Kawai
Shuji
S
Ito
Susumu
S
D000595:Amino Acid Sequence; D001407:Bacillus / Q000145:classification* / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D017931:DNA Primers; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000235:genetics*; D013816:Thermodynamics
D017931:DNA Primers; D012336:RNA, Ribosomal, 16S; D012697:Serine Endopeptidases