C.R.A. - RPS Consiglio per la Ricerca e la Sperimentazione in Agricoltura (Agricultural Research Council), Research Centre for the Soil-Plant System - Turin Research Group, Environment Park - Regione Piemonte, Via Livorno, 60 (A2 laboratori), 10144 Turin, Italy.
N Biotechnol. 2013 Sep 25;30(6):607-13. doi: 10.1016/j.nbt.2012.11.017. Epub 2012 Nov 29.
Whey and scotta are effluents coming from cheese and ricotta processing respectively. Whey contains minerals, lipids, lactose and proteins; scotta contains mainly lactose. Whey can be reused in several ways, such as protein extraction or animal feeding, while nowadays scotta is just considered as a waste; moreover, due to very high volumes of whey produced in the world, it poses serious environmental and disposal problems. Alternative destinations of these effluents, such as biotechnological transformations, can be a way to reach both goals of improving the added value of the agroindustrial processes and reducing their environmental impact. In this work we investigated the way to produce bioethanol from lactose of whey and scotta and to optimize the fermentation yields. Kluyveromyces marxianus var. marxianus was chosen as lactose-fermenting yeast. Batch, aerobic and anaerobic, fermentations and semicontinuous fermentations in dispersed phase and in packed bed reactor were carried out of row whey, scotta and mix 1:1 whey:scotta at a laboratory scale. Different temperatures (28-40°C) were also tested to check whether the thermotolerance of the chosen yeast could be useful to improve the ethanol yield. The best performances were reached at low temperatures (28°C); high temperatures are also compatible with good ethanol yields in whey fermentations, but not in scotta fermentations. Semicontinuous fermentations in dispersed phase gave the best fermentation performances, particularly with scotta. Then both effluents can be considered suitable for ethanol production. The good yields obtained from scotta allow us to transform this waste in a source.
乳清和斯考塔分别是奶酪和乳清干酪加工过程中的废水。乳清含有矿物质、脂肪、乳糖和蛋白质；斯考塔主要含有乳糖。乳清可以通过多种方式再利用，例如提取蛋白质或用于动物饲养，而如今斯考塔只是被视为一种废物；此外，由于全球乳清产量非常高，它带来了严重的环境和处理问题。这些废水的替代去向，如生物技术转化，可以是提高农业工业过程附加值和减少其环境影响的双重目标的一种途径。在这项工作中，我们研究了从乳清和斯考塔的乳糖生产生物乙醇并优化发酵产率的方法。马克斯克鲁维酵母 var. 马克斯克鲁维被选为乳糖发酵酵母。在实验室规模上进行了分批、好氧和厌氧发酵以及在分散相和填充床反应器中的半连续发酵，用于处理乳清、斯考塔和 1:1 乳清:斯考塔混合物。还测试了不同的温度（28-40°C），以检查所选酵母的耐热性是否可用于提高乙醇产率。在较低温度（28°C）下达到了最佳性能；高温也与乳清发酵中的高乙醇产率兼容，但在斯考塔发酵中不兼容。分散相的半连续发酵给出了最佳的发酵性能，特别是对于斯考塔。然后，这两种废水都可以被认为适合生产乙醇。从斯考塔获得的良好产率使我们能够将这种废物转化为一种资源。
