Cultivation and Lipid Production of Oleaginous Yeast on Canteen Food Waste

Food waste is the organic waste that is attractive for using as raw material in value-added bioproducts production via fermentation process. Canteen food waste was collected and determined the chemical composition. It mainly consisted of carbohydrate (49.24% dry basis, w/w) and subjected as feedstock for fermentable sugar and lipid production. The commercial ?amylase and glucoamylase were used for hydrolysis of 30% solid loading of food waste and presented total reducing sugar concentration of 169.13?5.67 g/L with a high glucose content (77.83% of total sugars). The oleaginous yeasts (Rhodotorula glutinis TISTR 5159, Yarrowia lipolytica TISTR 5621 and Rhodosporidium toruloides TISTR 5123) were cultivated on food waste hydrolysate. The results presented that R. glutinis TISTR 5159 and Y. lipolytica TISTR 5621 were an efficient and feasible in growth and lipid production on food waste hydrolysate containing 20 g/L of reducing sugar concentration. Y. lipolytica TISTR 5621, the highest biomass (3.95 g/L) and lipid content (12.82% of dry biomass) were achieved at 96 h of cultivation. The highest biomass and lipid content of R. glutinis TISTR 5159 were 5.91 g/L (at 384 h of cultivation) and 11.01% of dry biomass (at 288 h of cultivation), respectively. The lipid of Y. lipolytica TISTR 5621 was consisted of C16 and C18 as high as 99% of total fatty acid which could be an alternative feedstock for value-added products production.

餐厨垃圾属于有机废弃物，是通过发酵工艺制备高附加值生物基产品的优质原料。本研究采集食堂餐厨垃圾并测定其化学成分，结果显示其主要成分为碳水化合物（干基质量分数49.24%），可作为可发酵糖与油脂生产的原料。采用商用α-淀粉酶（α-amylase）与糖化酶（glucoamylase）对固含量30%的餐厨垃圾进行水解，水解液总还原糖浓度达169.13±5.67 g/L，其中葡萄糖占总糖的77.83%。以餐厨垃圾水解液为培养基，对三株产油酵母（oleaginous yeasts）——粘红酵母（Rhodotorula glutinis TISTR 5159）、解脂耶氏酵母（Yarrowia lipolytica TISTR 5621）及红冬孢酵母（Rhodosporidium toruloides TISTR 5123）进行培养。结果表明，在还原糖浓度为20 g/L的餐厨垃圾水解液中，粘红酵母TISTR 5159与解脂耶氏酵母TISTR 5621具备良好的生长与产脂可行性。解脂耶氏酵母TISTR 5621在培养96 h时获得最高生物量（3.95 g/L）与油脂含量（干菌体的12.82%）；粘红酵母TISTR 5159的最高生物量（5.91 g/L，培养384 h时）与油脂含量（干菌体的11.01%，培养288 h时）分别出现在对应培养时间点。解脂耶氏酵母TISTR 5621所产油脂的脂肪酸组成以C16与C18为主，占总脂肪酸的99%，可作为高附加值产品生产的替代原料。