Purification and characterization of an
extracellular chitinase from antagonistic Streptomyces violaceusniger
Anand Nagpure and Rajinder K. Gupta
Journal
of Basic Microbiology, 2012, 52, 1-11
The actinomycetes
Streptomyces violaceusniger showed strong antagonistic activity against
various tested wood rotting fungi. An extracellular chitinase, produced by Streptomyces violaceusniger, was purified in the following procedures: ammonium sulfate
precipitation and chromatographic separation of Q Sepharose. The molecular mass of the purified chitinase
was 48 kDa, estimated by a sodium dodecyl sulfatepolyacrylamide gel
electrophoresis. Chitinase was optimally active at pH of 5.0, and at
50°C. It retains almost 100% activity in the pH range of 5.0. This chitinase
has a high thermal tolerance and retained 100% of its activity at 50°C. Enzyme
activity was inhibited by Hg2+ and Ag+ cations, but was not
substantially inhibited by the K+ cation nor the chelating agent
EDTA. The apparent Km and Vmax values for pNP-(GlcNAc)2
were 0.1426 mM and 6.6 U/mg, respectively, at 37°C. The 48 kDa chitinase of Streptomyces violaceusniger is an exo-type enzyme, because maximum activity was obtained with
chromogenic substrate pNP-(GlcNAc)2.
http://onlinelibrary.wiley.com/doi/10.1002/jobm.201100648/abstract
http://onlinelibrary.wiley.com/doi/10.1002/jobm.201100648/abstract