Bacillus pumilus SG2 isolated from saline conditions produces and secretes two chitinases.
OBJECTIVE
Isolation and characterization of chitinases from a halotolerant Bacillus pumilus.


RESULTS
Bacillus pumilus strain SG2 was isolated from saline conditions. It is able to produce chitinase activity at high salt concentration. SDS-PAGE analysis of the B. pumilus SG2 culture supernatant showed two major bands that were induced by chitin. The amino acid sequence of the two proteins, designated ChiS and ChiL, showed a high homology with the chitinase of B. subtilis CHU26, and chitinase A of B. licheniformis, respectively. N-terminal signal peptide of both proteins was also determined. The molecular weight and isoelectric point of the chitinases were determined to be 63 and 74 kDa, and 4.5 and 5.1, for ChiS and ChiL respectively. The genes encoding for both chitinases were isolated and their sequence determined. The regulation of the chitinase genes is under the control of the catabolite repression system.


CONCLUSIONS
Secreted chitinase genes and their flanking region on the genome of B. pumilus SG2 have been identified and sequenced.


CONCLUSIONS
This is the first report of a multiple chitinases-producing B. pumilus halotolerant strain. We have identified two chitinases by using a reverse genetics approach. The chitinases show resistance to salt.
Ahmadian
G
G
Department of Molecular Genetic, National Institute for Genetic Engineering and Biotechnology, Tehran, Iran. ahmadian@nrcgeb.ac.ir
Degrassi
G
G
Venturi
V
V
Zeigler
D R
DR
Soudi
M
M
Zanguinejad
P
P
D000595:Amino Acid Sequence; D001407:Bacillus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002686:Chitin / Q000494:pharmacology; D002688:Chitinases / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D003470:Culture Media; D004269:DNA, Bacterial / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D007525:Isoelectric Focusing / Q000379:methods; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012965:Sodium Chloride / Q000494:pharmacology
D003470:Culture Media; D004269:DNA, Bacterial; D002686:Chitin; D012965:Sodium Chloride; D002688:Chitinases