Production of Cellulase and Xylanase Enzymes Using Distillers Dried Grains with Solubles (DDGS) by Trichoderma reeseiat Shake-Flask Scale and the Validation in the Benchtop Scale Bioreactor

Most of the corn-ethanol plants use dry-mill process and generate large volume of distillers dried grains with solubles (DDGS) as the co-product. The DDGS is a promising feedstock with rich content of cellulose and xylan. The goal of this study was to optimize cellulase and xylanase production byTrichoderma reesei(NRRL 6156) using DDGS as the carbon source at shake-flask and validate the results at benchtop bioreactors. The fermentation medium containing varied amounts of dilute-acid pretreated DDGS, yeast extract, and peptone were optimized for maximal enzyme production at 30 degrees C, pH 5.0 and 180 rpm with 3% (v/v) inoculum using Box-Behnken response surface methodology (RSM). Co-production of xylanase and cellulase enzymes was not achieved in the same medium; higher DDGS hydrolysate favored cellulase enzyme only while lower amount induced the xylanase enzyme. Based on the RSM results, maximal xylanase of 18.5 IU/mL was predicted with 5% DDGS hydrolysate, 0.1 g/L yeast extract, and 2 g/L peptone, while maximal cellulase of 1.1 IU/mL was predicted with 20% DDGS hydrolysate, 1 g/L yeast extract, and 0.5 g/L peptone. Of the two developed models from shake-flasks, xylanase model validated successfully the fermenter results giving 18.7 IU/mL of experimental xylanase in 1.5-L working volume bioreactor.


Optimization of dilute sulfuric acid, aqueous ammonia, and steam explosion as the pretreatments steps for distillers' dried grains with solubles as a potential fermentation feedstock
Iram, Attia; Çekmecelioğlu, Deniz; Demirci, Ali (Elsevier BV, 2019-06-01)
Distillers' dried grains with solubles (DDGS) is the by-product of bioethanol production from starch-rich grains through dry-mill fermentation. In this study, dilute sulfuric acid hydrolysis, aqueous ammonia, and steam explosion as the pre-treatment methods were optimized. The central composite response surface methodology (RSM) design was used for optimization of dilute acid pretreatment, aqueous ammonia pretreatment. The steam explosion trials were evaluated. The results show that the dilute acid pretreat...
Effects of High Hydrostatic Pressure (HHP) Processing and Temperature on Physicochemical Characterization of Insect Oils Extracted from Acheta domesticus (House Cricket) and Tenebrio molitor (Yellow Mealworm)
Ugur, Ahmet Erdem; Bolat, Berkay; Öztop, Halil Mecit; Alpas, Hami (Springer Science and Business Media LLC, 2020-11-01)
Oil portion of Tenebrio molitor (yellow mealworm) and Acheta domesticus (house cricket) were examined and it was investigated how the physicochemical properties of the oils changed with High Hydrostatic Pressure Assisted Extraction (HHP-E) and conventional solvent extraction (CE) with hexane. The effect of HHP-E at 500 MPa and 30 and 40 degrees C for 15 min on the properties of oils was compared with the CE. Following the extraction of oil, fatty acid composition, peroxide value, crystallization and melting...
Use of xylan, an agricultural by-product, in wheat gluten based biodegradable films: mechanical, solubility and water vapor transfer rate properties
Kayserilioglu, BS; Bakir, U; Yılmaz, Levent; Akkas, N (Elsevier BV, 2003-05-01)
The possibility of using xylan, as an agricultural by-product, for production of composite films in combinations with wheat gluten was investigated. Different levels of xylan (0-40% w/w) were incorporated into wheat gluten to form biodegradable composite films. Films were prepared at pH 4 and 11, and dried at either uncontrolled or controlled conditions. The mechanical properties, solubilities and water vapour transfer rate (WVTR) of the composite films were studied. Films were obtained with added xylan wit...
Detoxification of Groundnut Cake Naturally Contaminated with Aflatoxin B-1 Using Rhodococcus erythropolis in Shake Flask Bioreactors
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Degradation of aflatoxin B-1 in groundnut cake, a residue after oil extraction, by Rhodococcus erythropolis was optimized using response surface methodology. The bacterium was first grown in synthetic medium to determine optimal growth conditions using the combination of the Plackett-Burman and Box-Behnken methods and consequently aflatoxin B-1 in groundnut cake slurry was degraded under varying culture conditions. Optimal growth conditions were found as 22.5 A degrees C of temperature, pH 7, 100 mL of cult...
BALCI, S; Doğu, Timur; YUCEL, H (Wiley, 1994-08-01)
Ammonium chloride-impregnated and untreated almond shell and hazelnut shell samples were carbonized in a flow of nitrogen at relatively low temperatures. Pore structure characterization and sorption capacities of activated carbons prepared from shells of almond and hazelnut indicated that treatment with NH4Cl increased the total surface area and improved sorption characteristics. Chemical activation carried out at 350-degrees-C gave products with surface area values above 500 m2 g-1. On the other hand, the ...
Citation Formats
D. Çekmecelioğlu, “Production of Cellulase and Xylanase Enzymes Using Distillers Dried Grains with Solubles (DDGS) by Trichoderma reeseiat Shake-Flask Scale and the Validation in the Benchtop Scale Bioreactor,” WASTE AND BIOMASS VALORIZATION, pp. 0–0, 2020, Accessed: 00, 2020. [Online]. Available: