Full Length Research Paper

Enzymatic hydrolysis of pseudoplastic paint thickener (hydroxyethyl cellulose) by a local isolate of Aspergillus niger

Amani M. D. ElAhwany¹* and Eman A. H. Mohamed²

¹Faculty of Science, Botany Department, Alexandria University, Alexandria, Egypt.

²Faculty of Science, Botany Department, Alexandria University (Damanhour Branch), Alexandria, Egypt.

*Corresponding author. E-mail: amanielahwany@yahoo.com.

Accepted 6 October, 2008

A pseudoplastic paint manufactured by the Protal Paint Company in Alexandria, Egypt was examined for its quality to resist microbial degradation. The paint was hydrolyzed by extracellular endoglucanase of a local fungal isolate. The main hydrolysed component was the hydroxylethyl cellulose (HEC) thickener. The fungal isolate was identified as Aspergillus niger which showed a DNA monomorphism of 86% to A. niger ATCC 16404 by RAPD. A Plackett–Burman design was performed to determine the factors influencing endoglucanase activity. The analysis revealed the significance of negative effect of glucose concentration on endoglucanase specific activity.

Key words: Hydroxylethyl cellulose, Aspergillus niger, endoglucanase, Plackett-Burman.