Department of Microbiology, Faculty of Science, University of Maragheh, Maragheh, Iran.
Appl Biochem Biotechnol. 2012 Nov;168(5):1101-7. doi: 10.1007/s12010-012-9844-z. Epub 2012 Aug 30.
The extracellular lipase of Yarrowia lipolytica presents numerous potentialities for biotechnological applications. This work describes the development and storage of powders obtained from supernatants containing Y. lipolytica lipase by freeze-drying as downstream process that is important in obtaining a stable lipase powder with high enzymatic activity. Lipase was produced by Y. lipolytica U6 mutant strain in 20-L bioreactor. Non-concentrated cell-free culture supernatant samples were supplemented with different concentrations (0.5-1 %) of maltodextrin and glycerol as additives to freeze-drying. Effects of additives, temperature, pH, and storage time on lipase powders were determined. After addition of additives, freeze-drying yield increased 3.5-fold compared to supernatant without additive. Maltodextrin with 0.5 % concentration gave the best protection of lipase during dehydration treatment and its freeze-drying yield (77 %) is better than other formulations. Lipase powders were stored at 4 and 25 °C for 46 weeks without loss of lipase activity. A common impediment to the production of commercial enzyme is their low-stability aqueous solutions. The present study shows that freeze-dried lipase powders of Y. lipolytica have good stability for storage and various applications.
解脂耶氏酵母的细胞外脂肪酶具有许多生物技术应用的潜力。这项工作描述了通过冷冻干燥从含有解脂耶氏酵母脂肪酶的上清液中获得粉末的开发和储存，这是获得具有高酶活的稳定脂肪酶粉末的重要下游过程。脂肪酶由 Y. lipolytica U6 突变株在 20-L 生物反应器中生产。未浓缩的无细胞培养上清液样品中添加不同浓度（0.5-1%）的麦芽糊精和甘油作为冷冻干燥的添加剂。添加剂、温度、pH 值和储存时间对脂肪酶粉末的影响进行了测定。添加添加剂后，与无添加剂的上清液相比，冷冻干燥收率增加了 3.5 倍。浓度为 0.5%的麦芽糊精在脱水处理过程中对脂肪酶的保护作用最好，其冷冻干燥收率（77%）优于其他配方。脂肪酶粉末在 4 和 25°C 下储存 46 周，脂肪酶活性没有损失。商业酶生产的一个常见障碍是其在水溶液中的低稳定性。本研究表明，解脂耶氏酵母的冷冻干燥脂肪酶粉末具有良好的储存稳定性和多种应用。
