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Purification and
characterization of pectinmethylesterase from Aspergillus
repens isolated from cultivated soil
Arotupin, D. J.*,
Akinyosoye, F. A. and Onifade, A. K.
Department
of Microbiology, Federal University of Technology, PMB 704,
Akure, Ngeria.
*Corresponding author. E-mail:
daniel_juwon@yahoo.com.
Accepted
11 April, 2008 |
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Aspergillus repens
isolated from cultivated soils released pectinmethylesterase
(PME) into the liquid culture medium during growth. The
enzyme preparation was partially purified by ammonium
sulphate precipitation and dialysed. The ammonium sulphate-dialysate
fraction of the enzyme was separated by molecular exclusion
and ion exchange chromatography. The molecular weight of the
enzyme was found to be 141,300 daltons. The optimum
temperature for PME activity was 30oC and most
active at pH 6.5. The activity of the enzyme was stimulated
by Na+, K+, Ca2+, Mg2+
and Zn2+, while EDTA, PbCl2, HgCl2
and IAA inhibited enzyme activity. The activity of the
enzyme increased with increase in substrate concentration
reaching maximum at 4 mg/ml. The Lineweaver-Burk plot for
the hydrolysis of pectin indicated approximately 1.3 mg/ml.
These qualities could be explored during the industrial
applications of this enzyme.
Key
words:
Cultivated soils, pectimethylesterase, temperature, enzyme,
fraction. |
