title: Effect of media composition and growth conditions on production of beta-glucosidase by Aspergillus niger C-6.
abstract: The hydrolytic activity of fungal originated beta-glucosidase is exploited in several biotechnological processes to increase the rate and extent of saccharification of several cellulosic materials by hydrolyzing the cellobiose which inhibits cellulases. In a previous presentation, we reported the screening and liquid fermentation with Aspergillus niger, strain C-6 for beta-glucosidase production at shake flask cultures in a basal culture medium with mineral salts, corn syrup liquor, and different waste lignocellulosic materials as the sole carbon source obtaining the maximum enzymatic activity after 5-6 d of 8.5 IU/mL using native sugar cane bagasse. In this work we describe the evaluation of fermentation conditions: growth temperature, medium composition, and pH, also the agitation and aeration effects for beta-glucosidase production under submerged culture using a culture media with corn syrup liquor (CSL) and native sugar cane bagasse pith as the sole carbon source in a laboratory fermenter. The maximum enzyme titer of 7.2 IU/mL was obtained within 3 d of fermentation. This indicates that beta-glucosidase productivity by Aspergillus niger C-6 is function of culture conditions, principally temperature, pH, culture medium conditions, and the oxygen supply given in the bioreactor. Results obtained suggest that this strain is a potential microorganism that can reach a major level of enzyme production and also for enzyme characterization.
authors.affiliation: Departamentos de Bioprocesos y Biologia de la Unidad Profesional Interdisciplinaria de Biotecnologia, Instituto Politecnico Nacional (UPIBI/IPN), Av. Acueducto s/n. Col. Barrio La Laguna, Ticoman, Mexico, 07340, D. F. Mexico. okirchner003@yahoo.com.mx
authors.forename: O
authors.initials: O
authors.lastname: García-Kirchner
authors.forename: M
authors.initials: M
authors.lastname: Segura-Granados
authors.forename: P
authors.initials: P
authors.lastname: Rodríguez-Pascual
mesh_terms: D001234:Aspergillus niger / Q000145:classification / Q000201:enzymology* / Q000254:growth & development*; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation; D002482:Cellulose / Q000378:metabolism*; D003470:Culture Media / Q000378:metabolism; D004789:Enzyme Activation; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000517:prevention & control; D010865:Pilot Projects; D012037:Refuse Disposal / Q000379:methods; D031786:Saccharum / Q000382:microbiology; D012988:Soil Microbiology; D013045:Species Specificity; D013696:Temperature; D003313:Zea mays / Q000382:microbiology*; D001617:beta-Glucosidase / Q000032:analysis / Q000096:biosynthesis* / Q000737:chemistry*
chemical_list: D003470:Culture Media; D007220:Industrial Waste; D002482:Cellulose; C027433:bagasse; D001617:beta-Glucosidase