摘要：Background and Objectives: Pectinase as a fibrolytic enzyme is a main tool for effective use of pectin rich agro-residues as alternative feed resources. Production of pectinase by Aspergillus terreus on medium of sugar beet pulp to be used as a feed supplement for dairy animals was the main objective of this study. Materials and Methods: Impact of inoculum size ranged from 1-8% (v/v), incubation period from 1-7 days, initial pH of growth medium in a range between 3 and 8 and different nitrogen source ( ammonium sulphate, ammonium chloride peptone, yeast extract and urea) on pectinase production was studied. Electron microscope was used for investigate impact of the resultant pectinase on orange peel degradation, while batch culture technique was used for investigate impact of different levels of the produced and commercial pectinases on dairy animal’s diets digestibility by rumen microorganisms ( in vitro ). Results: Pectinase maximum production by Aspergillus terreus was obtained at pH 4 of the growth medium, ammonium sulphate as a sole nitrogen source, 4 days of incubation period and 7% of the inoculum size. All addition levels of the produced pectinases increased dietary dry matter (DM), acid detergent fiber (ADF) and neutral detergent fiber (NDF) degradability, but the maximal level of degradability was obtained by produced pectinase at 600 IU kg1 DM reached 11.44% over the control. Conclusion: Utilization of pectin rich agro-residues with locally produced pectinase in dairy animal feeding, may help in overcome of the feed gap beside the good impact on economy and environment.
