Mucor circinelloides is a filamentous fungus capable of producing mycelium-bound lipase and lipids and able to assimilate a wide array of substrates, like agricultural wastes and industrial effluents. A biotechnological valorization of cheese whey is described herein, in which simultaneous reduction of the organic loading and conversion of the various compounds of the by-product into added-value microbial metabolites is obtained. M. circinelloides URM 4182 was tested for the ability of producing biomass containing lipids and mycelium-bound lipase using raw cheese whey as culture medium. The fungal cultivation assays were performed in non-supplemented cheese whey at pH 4.5, 26 °C, 250 rpm for 120 h providing biomass concentration of 4.7 g L⁻¹ containing lipids (22.5% of dry biomass weight) and lipolytic activities up to 160 U g⁻¹. The mycelium-bound lipase was characterized in terms of its biochemical and kinetic parameters and tested on biogas production assays of cheese whey as a way to enhance the lipid hydrolysis, the limiting step in anaerobic digestion. Results demonstrate that the addition of M. circinelloides lipase on cheese whey reduced the lag phase of anaerobic digestion up to 43.7%, and the biogas production was increased by up to ninefold when compared with the control experiments.

中文翻译：

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增值微生物代谢产物的生产：油脂性真菌作为乳制品副产品增值的工具

Mucor circinelloides是一种丝状真菌，能够产生与菌丝体结合的脂肪酶和脂质，并能够吸收多种底物，例如农业废料和工业废水。本文描述了干酪乳清的生物技术增值，其中同时降低了有机负荷，并将副产物的各种化合物转化为增值的微生物代谢产物。使用未加工的干酪乳清作为培养基，测试了圆环分枝杆菌URM 4182产生包含脂质和与菌丝体结合的脂肪酶的生物质的能力。在非补充干酪乳清中在pH 4.5、26°C，250 rpm下进行真菌培养测定120小时，以提供4.7 g L ^-1的生物量浓度含脂质（占生物质干重的22.5％），脂解活性高达160 U g ^-1。结合菌丝体的脂肪酶的生化和动力学参数得到了表征，并在干酪乳清的沼气生产测定中进行了测试，以此作为增强脂质水解的方法，脂质水解是厌氧消化的限制步骤。结果表明，在干酪乳清上添加环丙纤维素酶脂肪酶可将厌氧消化的迟滞期减少高达43.7％，与对照实验相比，沼气产量最多可增加9倍。