4 research outputs found
Chitinase from Enterobacter sp. NRG4: Its purification, characterization and reaction pattern
Chitinase from Enterobacter sp. NRG4: Its purification, characterization and reaction pattern
Enterobacter sp. NRG4 was shown to excrete chitinase into the culture
supernatant when cultivated in medium containing chitin. A 60 kDa
extracellular chitinase was purified to homogeneity and characterized.
The enzyme hydrolyzed swollen chitin, colloidal chitin, regenerated
chitin and glycol chitin but did not hydrolyze chitosan. The chitinase
exhibited Km and Vmax values of 1.43 mg ml-1 and 83.33 \u3bcM
\u3bcg-1 h-1 for swollen chitin, 1.41 mg ml-1 and 74.07 \u3bcM
\u3bcg-1 h-1 for colloidal chitin, 1.8 mg ml-1 and 40 M \u3bcg-1 h-1
for regenerated chitin and 2.0 mg ml-1 and 33.33 \u3bcM \u3bcg-1 h-1
for glycol chitin, respectively. The optimal temperature and pH for
activity were 45\ub0C and pH 5.5, respectively. Mg2+, K+ and Ca2+
stimulated chitinase activity by 13, 16 and 18%, respectively whereas
Cu2+, Co2+, Ag+ and Hg2+ inhibited chitinase activity by 9.7, 15, 22
and 72.2%, respectively at 1 mM concentration. N-bromosuccinamide (NBS)
at 1 mM and iodoacetamide at 10 mM concentration completely inhibited
the enzyme activity. Dithiobisnitrobenzoic acid (DTNB) at 10 mM
concentration inhibited chitinase activity by 97.2%. Chitin was
hydrolyzed to chitobiose and N-acetyl D-glucosamine when incubated with
the purified enzyme. The hydrolysis pattern of the purified enzyme
indicated that the chitinase was an endochitinase
OPTIMIZATION OF MANNANASE PRODUCTION FROM STREPTOMYCES SP. PG-08-03 IN SUBMERGED FERMENTATION
Streptomyces sp. PG-08-3 was isolated from the desert of Rajasthan (India). The organism produced mannanase (15 Umg-1 protein) in the presence of 0.5% guar gum as a sole carbon source in minimal media by submerged fermentation (SmF). Enzyme production was enhanced by 7.3-fold when 0.5% soyabean meal and 0.25% of leucine were added to the minimal media. Increasing the guar gum concentration in the media by 0.1-1.0% resulted in linearly enhanced the production of mannanase
RESEARCH ARTICLE - Chitinase from Enterobacter sp. NRG4: Its purification, characterization and reaction pattern
Enterobacter sp. NRG4 was shown to excrete chitinase into the culture
supernatant when cultivated in medium containing chitin. A 60 kDa
extracellular chitinase was purified to homogeneity and characterized.
The enzyme hydrolyzed swollen chitin, colloidal chitin, regenerated
chitin and glycol chitin but did not hydrolyze chitosan. The chitinase
exhibited Km and Vmax values of 1.43 mg ml-1 and 83.33 μM
μg-1 h-1 for swollen chitin, 1.41 mg ml-1 and 74.07 μM
μg-1 h-1 for colloidal chitin, 1.8 mg ml-1 and 40 M μg-1 h-1
for regenerated chitin and 2.0 mg ml-1 and 33.33 μM μg-1 h-1
for glycol chitin, respectively. The optimal temperature and pH for
activity were 45°C and pH 5.5, respectively. Mg2+, K+ and Ca2+
stimulated chitinase activity by 13, 16 and 18%, respectively whereas
Cu2+, Co2+, Ag+ and Hg2+ inhibited chitinase activity by 9.7, 15, 22
and 72.2%, respectively at 1 mM concentration. N-bromosuccinamide (NBS)
at 1 mM and iodoacetamide at 10 mM concentration completely inhibited
the enzyme activity. Dithiobisnitrobenzoic acid (DTNB) at 10 mM
concentration inhibited chitinase activity by 97.2%. Chitin was
hydrolyzed to chitobiose and N-acetyl D-glucosamine when incubated with
the purified enzyme. The hydrolysis pattern of the purified enzyme
indicated that the chitinase was an endochitinase