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Purification, characterization, and gene cloning of a chitinase from Stenotrophomonas maltophilia N4
Author(s) -
Jankiewicz Urszula,
Brzezinska Maria Swiontek
Publication year - 2015
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.201400717
Subject(s) - chitinase , chitin , stenotrophomonas maltophilia , chemistry , hydrolysis , chitosan , enzyme , cysteine , biochemistry , biology , bacteria , pseudomonas aeruginosa , genetics
The Stenotrophomonas maltophilia synthesises high‐activity chitinase in response to chitin or chitosan induction. The enzyme was purified 8.5 fold and subjected to characterisation. The optimum hydrolysis conditions for this enzyme when using colloidal chitin as substrate were pH 5.6 and temperature of 45 ° C. The enzyme demonstrated high thermal stability at 45 ° C within 2 h. The studied chitinase exhibited high activity towards colloidal chitin, glycol chitin and chitosan, while it did not hydrolyse glycosidic bonds in carboxymethylcellulose. The enzyme exhibited the highest activity, equalling 90 U/ml, towards Nitrophenyl β‐D‐N,N′,N″‐triacetylchitotriose and activity of 37 U/ml towards 4‐Nitrophenyl N,N′‐diacetyl‐β‐D‐chitobioside. The K m value in the presence of the two former substrates was:1.2 and 3.9 mM, respectively, which classifies the studied enzyme as an endochitinase. Cysteine and 2‐mercaptoethanol stimulated to a small degree the activity of the chitinase which may indicate the involvement of cysteine residues in the catalysis mechanism. The full length of the nucleotide sequence of this chitinase gene is 2106 bp, which amounts to 702 amino acids.