Bioethanol production of cheese whey in continuous culture

Abstract

The cheese industry produces a large amount of waste, the equivalent of 9L of cheese whey for every 10L of milk (Murari et al., 2018; Pendon et al., 2021; Sar et al., 2021). Whey is composed by lactose and proteins, mainly (Murari et al., 2018; Murari et al., 2019; Tesfaw et al., 2021). In most cases, cheese whey had not added value or specific use, being discarded and causing very important environmental implications (Maruri et al., 2018; Tesfaw et al., 2021; Sar et al., 2021). In the present study, the production of bioethanol from cheese whey were analyzed, using Kluyveromyces marxianus as inoculum, under continuous culture conditions (28°C, agitation at 100 rpm, aeration at 1 vvm, feed at 8.63 mL/min), where it was established that is possible to obtain yields of 0.62 g of ethanol per g of lactose in the first 18 h, this makes it feasible for the continuous production of ethanol with cheese whey with minimal pretreatment.