Abstract
The production of protein-enriched microbial biomass for animal feed has recently gained importance in livestock and agriculture.Single cell protein (SCP), microbial cell biomass, serves as a sustainable source of protein in livestock and poultry nutrition, meeting the increasing consumer demand for dairy products.The cultivation of microbial cells on low-cost raw materials can provide their high growth rate, biomass yield and nutrient content.Agricultural wastes such as wheat bran, wheat straw, various types of stillage, and dairy wastes can be used by microbial cells to produce SCP.The use of yeast cultures in a consortium with lactic acid bacteria (LAB) allows the production of feed additives with high fermentative (acid-forming) and probiotic activity.This study aims to develop mixed cultures of yeasts and LAB and characterise their activities for feed fortification.Consortia (mixed cultures) of yeast and LAB strains was formed in a ratio 1:1 on the basis of Pichia fermentans TD1 + Lactobacillus plantarum AP-17 and Yarrowia lipolytica A1 + Lactobacillus murinus AK-17.Cultivating research consortia showed that Yarrowia lipolytica A1 + Lactobacillus plantarum AP-17 had a higher amount of viable cells (35.7 × 10 6 CFU mL -1 ) growing on the selected natural substrates (milk whey and wheat bran).Considering nutritional and energy values of yeast and LAB consortia grown on different substrates, mixed cultures of Yarrowia lipolytica A1 + Lactobacillus plantarum AP-17 demonstrated highest values while growth on milk whey, specifically, protein 2.73 ± 0.12%, fat -0.62 ± 0.40%, carbohydrate -2.80 ± 0.08% and moisture 95.9 ± 0.20% compared to control.Thus, consortia of Yarrowia lipolytica A1 + Lactobacillus plantarum AP-1 can be proposed as a promising mixed culture for producing novel protein-rich feeds with probiotic properties.