Sustainability of the current global food system needs to be revaluated. Food waste, particularly that coming from the dairy industry accounts for a large portion of the food system’s global warming potential. The large amounts of energy and resources required to power this food system call for efforts to reduce the burden of emissions from the dairy industry. At the consumer and industrial level, waste in the dairy industry occurs through by-products and food loss due to spoilage or contamination. Previous efforts have been introduced and studied to combat this waste and loss through biopreservation. The present work aims to expand on these opportunities by studying some biotechnological approaches for preservation of dairy products to reduce waste. First, enzymes endogenous to barley were studied for their ability to hydrolyze the lactose in dairy by-products making it available as fermentable sugars. Measurement of residual glucose levels in acid whey mashes containing barley indicated successful hydrolysis of the lactose. This led to successful fermentation of acid whey with the yeast Saccharomyces cerevisiae to produce ~2.6% ABV ethanol. Next, lactic acid bacteria were evaluated for their bioprotection ability to enhance the food safety of fresh-style cheese from Listeria monocytogenes. Application of several species of lactic acid bacteria into a lab-scale fresh cheese model revealed that they had an insignificant effect on reducing or limiting listerial growth at multiple inoculation levels (2 or 4 log CFU/g L. monocytogenes) and two temperatures (6°C or 21°C). Further evaluation of these species or incorporation with additional control strategies is necessary in order to implement this approach. Building upon the enzymatic hydrolysis of acid whey, a lactose-utilizing yeast, Brettanomyces claussenii was then evaluated for its potential to valorize lactose-containing dairy by-products by producing acetic acid. Optimization of these fermentations was done through a screening design and response surface methodology to determine the best fermentation conditions for acetic acid production with this yeast. Additionally, a molecular biology and bioinformatic approach was used to probe the genomic mechanism responsible for the lactose metabolism of this yeast. Cloning of two putative genes from B. claussenii into S. cerevisiae confirmed identity of a beta-galactosidase (LAC4) and lactose permease (LAC12) gene. The information gained from these approaches allows for the potential of additional applications to reduce food waste in the dairy industry. Reutilization of by-products to produce value-added goods or enhancement of food safety through bioprotection schemes can provide powerful opportunities to increase sustainability in the dairy industry.