Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Gıda Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2019
Öğrenci: Ayşe Sultan Kurt
Danışman: DENİZ ÇEKMECELİOĞLU
Özet:Grape pomace is the major waste in the wine industry and it consists of high moisture content and residual sugars, which make it susceptible to rapid microbial spoilage. Thus, it needs to be disposed of with care to eliminate both environmental and health problems. The carbohydrate fraction of grape pomace is a fibrous material, and is an additional source of fermentable sugars to produce biofuel and hydrolytic enzymes. In this study, grape pomace hydrolysate was used for cellulase production with Bacillus subtilis Natto DSM 17766 at 37 °C and 130 rpm using batch fermentation method. Cellulase production was optimized for solid loading of grape pomace, pH, and fermentation period by Box-Behnken response surface method. Furthermore, cellulase was produced by Bacillus subtilis NRRL B-4219 using monosaccharides which were mixed to obtain similar sugar content with grape pomace. Cellulase activity from both carbon sources were assayed by the DNS method using filter paper as substrate. The maximum cellulase activity was obtained as 0.48 IU/mL from experiments conducted by synthetic sugar, which has the monosaccharide combination of glucose, fructose, xylose, arabinose, mannose, and galactose. In contrast, the highest cellulase activity using grape pomace was achieved at 0.196 IU/mL with 12.5% of solid loading at pH 7.0 on 5th day. The quadratic response surface model predicted an optimal cellulase activity of 0.178 IU/mL with 15% solid loading and pH 6.0 on 7th day. These results indicate that grape pomace is a potential carbon source for bacterial cellulase production.