title: Efficient polygalacturonase production from agricultural and agro-industrial residues by solid-state culture of Aspergillus sojae under optimized conditions.
abstract: Previously identified fungal pectinase producers of the species Aspergillus sojae were used for optimization of polygalacturonase production in solid-state fermentation applying Design of Experiment. The effects of media composition and several process parameters, like inoculum size, moisture level, incubation time and temperature on polygalacturonase activity were studied in screening and optimization investigations. Utilization of agricultural and agro-industrial by-products provided the establishment of a cost-efficient and sustainable process for enzyme production. Comparison of pectinase production by A. sojae ATCC 20235 and A. sojae CBS 100928 under optimized conditions yielded 6.9 times higher polygalacturonase activity by A. sojae ATCC 20235. Highest enzyme yield (909.5 ± 2.7 U/g) was obtained by A. sojae ATCC 20235 after 8 days at 30°C applying 30% sugar beet pulp as inducer substrate in combination with wheat bran as medium wetted at 160% with 0.2 M HCl. Furthermore, an overview of pectinolytic enzyme activities present in the extracts of both strains is provided. Protein profiles of both strains are given by SDS-PAGE electrophoresis, as well as zymograms for pectinolytic enzymes in comparison to commercial pectinase preparations.
authors: Downstream Processing Laboratory, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany.
authors: Doreen
authors: D
authors: Heerd
authors: Downstream Processing Laboratory, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany.
authors: Sonja
authors: S
authors: Diercks-Horn
authors: Downstream Processing Laboratory, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany.
authors: Marcelo
authors: M
authors: Fernández-Lahore
keywords: Agro-industrial residues; Aspergillus sojae; Design of Experiment; Polygalacturonase; Solid-state fermentation