Valorisation of Agro-Food Wastes for Obtaining of Natural Bioactive Yeasts Preparations with Phytostimulatory Effect

The management of agro-food waste has a significant positive impact on the environment and supports a more sustainable food safety policy. Eco-friendly, effective microbial biofertilizers are important for enhancing food security by improving plant productivity and crop quality. This study aimed to determine the effects of bioactive yeast preparations derived from agro-food wastes on plant growth. Waste from beer production and carrot processing was reused to produce bioactive yeast preparations. In the given experiments, wheat seeds were pretreated with protein- and carotenoid-rich extracts. Carotenoid extract from yeast Rhodotorula mucilaginosa has contributed to the maximum increase of wheat seedlings' biomass by 43.7% and of root biomass by 78.1% compared to the control at its optimal concentration of 0.5%. Protein preparation from Hansenula anomala has contributed to the maximum increase of wheat seedlings' biomass by 168.0% compared to the control, using the optimal concentration of 0.5% of protein extract, and of root biomass with 60.0 – 57.1% compared to the control in the limits of concentrations of 1-2%. The biofertilizers obtained can improve crop nutritional quality, ensuring food safety.