Chinedu, S. N. and Nwinyi, Obinna and Okochi, V. I.
(2008)
Properties of Endoglucanase of Penicillium chrysogemum PCL501.
Australian Journal of Basic and Applied Sciences, 2 (3).
pp. 738-746.
ISSN 1991-8178
Abstract
Crude extracellular enzyme from a 3-day culture of Penicillium chrysogenum (PCL 501),
in basal medium containing cellulose as the sole carbon source, yielded 0.67 ± 0.03, 19.94 ± 1.30 and
8.50 ± 0.50 units mg protein-1 of 1, 4- â-endoglucanase, â-glucosidase and xylanase activity
respectively. The crude enzyme was subjected to ammonium sulphate precipitation (80% saturation)
and gel filtration. A purification-fold of 7.5 was achieved. Two active fractions of 1, 4 âendoglucanase
(EC 3. 2. 1. 4), which exhibited about the same activity towards carboxymethylcellulose
(CMC), were obtained and pooled for the subsequent analyses. The endoglucanase gave a
Vmax of 10.0 ± 0.4 μmol min-1 mg protein-1 and Km of 11.8 ± 0.4 gL-1 with CMC. The enzyme was
most active at pH of 4.5 – 5.0 and temperature range of 40 – 50 OC. The optimum pH was 4.9 while
the Optimum temperature was 48 OC. Divalent metal ions and EDTA affected the enzyme activity at
2.0 mM concentrations. Mn2+ and Fe2+ had stimulatory effects on the enzyme whereas Mg2+, Cu2+,
Zn2+, Hg2+ and EDTA inhibited the enzyme activity. The effect of Ca2+ was not significant. Over 3-
fold increase in the enzyme activity was recorded with Mn2+. Percentage inhibition of 65.9 and 79.7
respectively was obtained with Hg2+ and EDTA. The organism appears to produce two types of
endoglucanase which differed in their molecular weight but not significantly in their activity.
The enzyme activity was highly stimulated by manganese ion and inhibited by the metal-chelating
agent, EDTA.
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