Abstract
Whey generated in cheese manufacturing processes serious environmental issues that limit process profitability. The dairy industry's innovation recognises the "bio-refinery" as a key to successful whey disposal and economic growth. The valorisation of cheese whey is a multi-technological process that can result in value-added products (biomass, fine or bulk chemicals).The aim of this research is to improve a fermentation method that uses whey as a growth medium and carbon source. Lactose, which is abundant in whey, is an important carbon source. However, the yeast Saccharomyces cerevisiae, which is more commonly utilised in commercial fermentation processes, is not a lactose-fermenting yeast. We designed a novel biotechnological technique for the large-scale synthesis of non-genetically modified yeast biomass that may be employed in a variety of applications, such as bread making, production of probiotics, nutraceuticals, bio-active molecules. To use cheese whey as a raw material for S. cerevisiae production and to overcome the limitations in the use of lactose we used externally added substrates such as peptone, yeast extract and casein. The careful optimization of the amount of additional substrate allowed for the slow release of glucose and galactose via hydrolysis and simultaneous consumption, resulting in a decrease in ethanol and an increase in biomass produced.