PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Citation - WoS: 3Citation - Scopus: 4Evaluation of Agro-Industrial Wastes, Their State, and Mixing Ratio for Maximum Polygalacturonase and Biomass Production in Submerged Fermentation(Taylor and Francis Ltd., 2015) Göğüş, Nihan; Evcan, Ezgi; Evcan, Ezgi; Cavalitto, Sebastian F.; Tarı, Canan; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe potential of important agro-industrial wastes, apple pomace (AP) and orange peel (OP) as C sources, was investigated in the maximization of polygalacturonase (PG), an industrially significant enzyme, using an industrially important microorganism Aspergillus sojae. Factors such as various hydrolysis forms of the C sources (hydrolysed-AP, non-hydrolysed-AP, hydrolysed-AP + OP, non-hydrolysed-AP + OP) and N sources (ammonium sulphate and urea), and incubation time (4, 6, and 8 days) were screened. It was observed that maximum PG activity was achieved at a combination of non-hydrolysed-AP + OP and ammonium sulphate with eight days of incubation. For the pre-optimization study, ammonium sulphate concentration and the mixing ratios of AP + OP at different total C concentrations (9, 15, 21 g-1) were evaluated. The optimum conditions for the maximum PG production (144.96 ml-1) was found as 21 g-1 total carbohydrate concentration totally coming from OP at 15 g-1 ammonium sulphate concentration. On the other hand, 3:1 mixing ratio of OP + AP at 11.50 g-1 ammonium sulphate concentration also resulted in a considerable PG activity (115.73 ml-1). These results demonstrated that AP can be evaluated as an additional C source to OP for PG production, which in turn both can be alternative solutions for the elimination of the waste accumulation in the food industry with economical returns.Article Citation - WoS: 52Citation - Scopus: 62Solid-State Production of Polygalacturonase by Aspergillus Sojae Atcc 20235(Elsevier Ltd., 2007) Üstok, Fatma Işık; Tarı, Canan; Tarı, Canan; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe effect of solid substrates, inoculum and incubation time were studied using response surface methodology (RSM) for the production of polygalacturonase enzyme and spores in solid-state fermentation using Aspergillus sojae ATCC 20235. Two-stage optimization procedure was applied using D-optimal and face-centered central composite design (CCD). Crushed maize was chosen as the solid substrate, for maximum polygalacturonase enzyme activity based on D-optimal design. Inoculum and incubation time were determined to have significant effect on enzyme activity and total spore (p < 0.01) based on the results of CCD. A second order polynomial regression model was fitted and was found adequate for individual responses. All two models provided an adequate R2 of 0.9963 (polygalacturonase) and 0.9806 (spores) (p < 0.001). The individual optimum values of inoculum and incubation time for maximum production of the two responses were 2 × 107 total spores and 5-6 days. The predicted enzyme activity (30.55 U/g solid) and spore count (2.23 × 107 spore/ml) were very close to the actual values obtained experimentally (29.093 U/g solid and 2.31 × 107 spore/ml, respectively). The overall optimum region considering the two responses together, overlayed with the individual optima. Solid-state fermentation provided 48% more polygalacturonase activity compared to submerged fermentation under individually optimized conditions.