Donzella Silvia, Fumagalli Andrea, Contente Martina Letizia, Molinari Francesco, Compagno Concetta
Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy.
Biotechnol Appl Biochem. 2024 Aug;71(4):712-720. doi: 10.1002/bab.2570. Epub 2024 Feb 26.
Organic waste valorization is one of the principal goals of the circular economy. Bioprocesses offer a promising approach to achieve this goal by employing microorganisms to convert organic feedstocks into high value products through their metabolic activities. In this study, a fermentation process for yeast cultivation and extracellular lipase production was developed by utilizing food waste. Lipases are versatile enzymes that can be applied in a wide range of industrial fields, from detergent, leather, and biodiesel production to food and beverage manufacturing. Among several oleaginous yeast species screened, Saitozyma flava was found to exhibit the highest secreted lipase activity on pNP-butyrate, pNP-caproate, and pNP-caprylate. The production medium was composed of molasses, a by-product of the sugar industry, which provided nutrients for yeast biomass formation. At the same time, waste cooking oil was employed to induce and enhance extracellular lipase production. After 48 h of process, 20 g/L of yeast biomass and 150 mU/mg of lipase activity were achieved, with a productivity of 3 mU/mg/h. The purified lipase from S. flava showed optimal performances at temperature 28°C and pH 8.0, exhibiting a specific activity of 62 U/mg when using p-NPC as substrate.
有机废物的增值是循环经济的主要目标之一。生物过程提供了一种很有前景的方法来实现这一目标，即利用微生物通过其代谢活动将有机原料转化为高价值产品。在本研究中，开发了一种利用食物垃圾进行酵母培养和胞外脂肪酶生产的发酵工艺。脂肪酶是一种多功能酶，可应用于广泛的工业领域，从洗涤剂、皮革、生物柴油生产到食品和饮料制造。在筛选的几种产油酵母物种中，发现黄氏赛多孢酵母对对硝基苯丁酯、对硝基苯己酯和对硝基苯辛酯表现出最高的分泌脂肪酶活性。生产培养基由制糖工业的副产品糖蜜组成，它为酵母生物质的形成提供营养。同时，使用废弃食用油来诱导和提高胞外脂肪酶的产量。经过48小时的工艺过程，获得了20 g/L的酵母生物质和150 mU/mg的脂肪酶活性，生产率为3 mU/mg/h。从黄氏赛多孢酵母纯化的脂肪酶在温度28°C和pH 8.0时表现出最佳性能，以对硝基苯辛酯为底物时比活性为62 U/mg。
