Utilising Dairy and Whisky Manufacture By-products for Microalgal Lipids Production

Microalgae are increasingly recognised as a renewable and sustainable source of both unsaturated and saturated fatty acids (SFAs), offering a viable alternative to traditional animal fats and plant oils. By-products of food production, such as whey from cheese production andDSG obtained from whiskey production, were found to be nutrient-dense streams and have potential for valorisation. Both whey and DSG were found to contain varied concentrations of nutrients, especially nitrate, phosphate and sugars and were shown to support microalgal growth and production of various fatty acids. C. vulgaris achieved 4.27 ± 0.31 g/L biomass when grown in whey. It also outperformed T. lutea in lipid production in DSG with significantly higher ( p < 0.05) lipid synthesis on day 19, achieving a total fatty acid content of 308.20 ± 106.49 mg/g biomass dw. Both microalgae strains produced SFAs such as palmitic acid (C16:0), stearic acid (C18:0) and oleic acid (C18:1 cic-9) MUFA in whey and DSG. Additionally, T. lutea produced lauric acid (C12:0), myristic acid (C14:0) and unsaturated palmitoleic acid (C16:1 ω-7) in whey and DSG to varying degrees. The findings indicate that microalgae can produce a distinct range of fatty acids when cultivated in both whey and DSG. The present study aims to evaluate the efficiency of microalgae in lipid production and the ability to synthesise a variety of fatty acids when utilised for the valorisation of various substrates.