title: Some factors affecting tannase production by Aspergillus niger Van Tieghem.
abstract: One variable at a time procedure was used to evaluate the effect of qualitative variables on the production of tannase from Aspergillus niger Van Tieghem. These variables including: fermentation technique, agitation condition, tannins source, adding carbohydrates incorporation with tannic acid, nitrogen source type and divalent cations. Submerged fermentation under intermittent shaking gave the highest total tannase activity. Maximum extracellular tannase activity (305 units/50 mL) was attained in medium containing tannic acid as tannins source and sodium nitrate as nitrogen source at 30 °C for 96 h. All added carbohydrates showed significant adverse effects on the production of tannase. All tested divalent cations significantly decreased tannase production. Moreover, split plot design was carried out to study the effect of fermentation temperature and fermentation time on tannase production. The results indicated maximum tannase production (312.7 units/50 mL) at 35 °C for 96 h. In other words, increasing fermentation temperature from 30 °C to 35 °C resulted in increasing tannase production.
authors.affiliation: Department of Food Science and Technology, Faculty of Agriculture, Alexandria University, Alexandria, Egypt.
authors.forename: Hamada A
authors.initials: HA
authors.lastname: Aboubakr
authors.forename: Malak A
authors.initials: MA
authors.lastname: El-Sahn
authors.forename: Amr A
authors.initials: AA
authors.lastname: El-Banna
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology*; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002413:Cations, Divalent / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000378:metabolism; D005285:Fermentation; D013696:Temperature; D013997:Time Factors
chemical_list: D002413:Cations, Divalent; D003470:Culture Media; D004791:Enzyme Inhibitors; D002265:Carboxylic Ester Hydrolases; C022711:tannase
keywords: Aspergillus niger Van Tieghem; factors affecting tannase production; split plot design; tannase