Abstract A by-product of cheese industry – whey, is often used as a source in a microbiological lactic acid production. However, an activity of microorganisms naturally occurring in whey causing an imbalance in downstream microbiological processes. Thus, the whey permeate was indicated as appropriate medium to LA production, because a microfiltration is a type of sterilization – named very often “cold sterilization” and provide a pure and sterilize medium. The goal of this study was to identify the optimal concentrations of peptone, egg and yeast extract needed to re-supplement whey permeate medium – using for industrial scale LA production, because whey permeate is almost pure lactose solution. The highest value of LA production (27.5 g L−1) was obtained in the medium which contained 5 g L−1 peptone, 8 g L−1 egg extract and 0.2 g L−1 yeast extract. A cost of LA production using this composition medium was 0.11 € g−1 produced LA and almost 100 % of lactose was utilized after 24 h of process (only 2 % of the initial lactose was present in the spent medium). Additionally, a possible decrease of process efficiency in case of glucose (originally presents in MRS) by lactose replacement was examined. A measurement of substrate and product concentration during cultivation showed that glucose can be successfully replaced by lactose without decreasing the efficiency of production.

中文翻译：

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用于乳酸工业微生物生产的无蛋白废乳清补充剂的优化

摘要 奶酪工业的副产品——乳清，通常用作微生物乳酸生产的来源。然而，乳清中天然存在的微生物活动会导致下游微生物过程的不平衡。因此，乳清渗透液被认为是 LA 生产的合适介质，因为微滤是一种灭菌 - 通常称为“冷灭菌”并提供纯净的灭菌介质。本研究的目标是确定补充乳清渗透培养基所需的蛋白胨、鸡蛋和酵母提取物的最佳浓度——用于工业规模的 LA 生产，因为渗透乳几乎是纯乳糖溶液。在含有 5 g L-1 蛋白胨、8 g L-1 鸡蛋提取物和 0. 2 g L-1 酵母提取物。使用这种组合培养基生产 LA 的成本是 0.11 € g-1 生产的 LA，并且在 24 小时的过程后几乎 100% 的乳糖被利用（只有 2% 的初始乳糖存在于用过的培养基中）。此外，研究了在葡萄糖（最初存在于 MRS 中）的情况下通过乳糖替代可能降低的工艺效率。培养过程中底物和产物浓度的测量表明，葡萄糖可以成功地被乳糖替代，而不会降低生产效率。研究了在葡萄糖（最初存在于 MRS 中）的情况下，通过乳糖替代可能会降低工艺效率。培养过程中底物和产物浓度的测量表明，葡萄糖可以成功地被乳糖替代，而不会降低生产效率。研究了在葡萄糖（最初存在于 MRS 中）的情况下，通过乳糖替代可能会降低工艺效率。培养过程中底物和产物浓度的测量表明，葡萄糖可以成功地被乳糖替代，而不会降低生产效率。