Food Engineering / Gıda Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/12

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Scopus Q: search.filters.scopusQuartile.Q2Subject: search.filters.subject.Solid-state fermentation

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  • Article
    Citation - WoS: 69
    Citation - Scopus: 89
    Pectinase Enzyme-Complex Production by Aspergillus Spp. in Solid-State Fermentation: a Comparative Study
    (Elsevier, 2012) Heerd, Doreen; Yeğin, Sırma; Tarı, Canan; Fernandez Lahore, Marcelo
    A comparative evaluation of three Aspergillus species according to their pectinase production in solid-state fermentation was performed. Solid-state fermentation offers several potential advantages for enzyme production by fungal strains. Utilization of agricultural by-products as low-cost substrates for microbial enzyme production resulted in an economical and promising process. The pectinolytic enzyme activities of two Aspergillus sojae strains were compared to a known producer, Aspergillus niger IMI 91881, and to A. sojae ATCC 20235, which was re-classified as Aspergillus oryzae. Evaluation of polymethylgalacturonase and polygalacturonase activity was performed as well as exo- vs. endo-enzyme activity in the crude pectinase enzyme-complex of the mentioned strains. Furthermore, a plate diffusion assay was applied to determine the presence and action of proteases in the crude extracts. A. sojae ATCC 20235 with highest polymethylgalacturonase activity and highest polygalacturonase activity both exo- and endo-enzyme activity, is a promising candidate for industrial pectinase production, a group of enzymes with high commercial value, in solid-state fermentation processes. Beside the enzymatic assays a protein profile of each strain is given by SDS-PAGE electrophoresis and in addition species-specific zymograms for pectinolytic enzymes were observed, revealing the differences in protein pattern of the A. sojae strains to the re-classified A. oryzae. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 52
    Citation - Scopus: 62
    Solid-State Production of Polygalacturonase by Aspergillus Sojae Atcc 20235
    (Elsevier Ltd., 2007) Üstok, Fatma Işık; Tarı, Canan; Göğüş, Nihan
    The 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.