Journal of Biotechnology & Biomaterials
Open Access

Abstract

Exo-Polygalacturonase (Exo-PG) produced from a newly isolated Aspergillus niger AUMC 4156 in fermentation media containing sugar beet pulp as a sole carbon source was separated and purified by filtration, ammonium sulfate precipitation, dialysis, cold acetone precipitation and sephadex G-200 gel filtration chromatography. The specific activity of the purified enzyme increased from 0.88 to 5.75 U/ml, with an overall recovery rate of 23% of the crude enzyme. The optimum temperature and PH values for the function of the purified enzyme were 45 o C and 4.0, respectively. Thermal and P H stability of the purified Exo- PG indicated that it was almost stable at 30 o C and 40 o C for up to 3.5 and 1.0 h respectively. Also, it was stable at acidic PH (3-6) but its stability decreased at higher P H values. The Km and Vmax.values of Exo-PG were 1.0 mg/ml and 6.9 u mole galacturonic acid/min/mg protein respectively.

Biography

Ragab W S M is the professor of Food Microbiology and Head of Food Sxeince and Technology Department, Assiut University, Egypt. He did his PhD in Food Science & Technology (1990-194) with the research title: Studies on some mycotoxins in certain foodstuffs. From 2007-2011, he served as Head of The Agricultural Department, Sugar Technology Institute, Assiut University, Assiut, Egypt.His research interest includes Food Microbiology and Mycotoxins. He attended more than 10 International Conferences, supervised more than 10 PhDthesis and has more than 20 publications.