Yeast is a microbial fertilizer that can be used as a composting agent for organic materials, a component of compound microbial fertilizers, a bio-organic fertilizer, and one of the microbial strains in microbial inoculants. It is suitable for use in bio-fertilizers, bio-feed, and bio-pesticides. It appears as light white granules.

1. Fermentation and Improvement of Organic Fertilizers

   • Decomposing Organic Matter: Yeast participates in compost fermentation, accelerating the breakdown of organic waste such as straw and animal manure into humus, enhancing soil fertility.
   • Nutrient Release: During decomposition, it releases nitrogen, phosphorus, potassium, and trace elements, increasing the availability of nutrients in the soil.
   • Pathogen Suppression: Organic acids produced during fermentation can reduce harmful microorganisms in the soil.

2. Biological Control and Plant Health

   • Antagonizing Pathogens: Some yeast species (e.g., Pseudozyma) can suppress plant pathogenic fungi (e.g., botrytis and powdery mildew) by competing for nutrients
   • Inducing Resistance: Activates the plant immune system, enhancing resistance to diseases and environmental stresses (e.g., drought, salinity).
   • Promoting Growth: Secretes growth hormones (such as indole acetic acid) that stimulate root development, increasing crop yields.

3. Environmental Protection and Circular Agriculture

   • Agricultural Waste Treatment: Used to process fruit and vegetable processing waste, distiller's grains, etc., converting them into feed or fertilizers to reduce pollution.

1. Water Quality Regulation

   • Decomposing Organic Matter: Breaks down leftover feed and waste, reducing harmful substances such as ammonia nitrogen and nitrites, thereby improving water quality.
   • Stabilizing Algal Balance: Competes to inhibit the overgrowth of harmful algae, maintaining ecological balance in the water.

2. Feed Additive

   • Nutritional Enhancement: Yeast is rich in protein, B vitamins, and nucleotides, serving as a feed supplement to improve growth performance in fish and shrimp.
   • Enhanced Immunity: Components like β-glucan activate the immune system of aquatic animals, reducing the incidence of diseases.
   • Antibiotic Replacement: Acts as a probiotic to reduce pathogenic bacteria (e.g., vibrios) in the gut, promoting gut health.

3. Resource Utilization

   • Fermented Feed: Utilizes yeast to ferment plant proteins such as soybean meal and rapeseed meal, degrading anti-nutritional factors and improving feed utilization.

1. Feed Fermentation and Nutritional Enhancement

   • Silage Feed: Adding yeast promotes lactic acid fermentation, suppressing spoilage bacteria and improving the nutritional value and palatability of silage feed.
   • Single-Cell Protein (SCP): Cultivating yeast on industrial wastes (e.g., molasses) produces high-protein feed (e.g., feed yeast), serving as a substitute for soybean meal and fish meal.

2. Animal Health Management

   • Gut Probiotics: Regulates the microbial balance in the rumen of ruminants, improving fiber digestion; inhibits pathogenic bacteria like E. coli in poultry and pigs.
   • Stress Relief: Yeast cell wall polysaccharides (e.g., mannan oligosaccharides) enhance immunity and reduce stress responses from transport and weaning.

3. Manure Treatment and Emission Reduction

   • Odor Reduction and Pollution Control: Ferments livestock manure to decrease emissions of harmful gases such as ammonia and hydrogen sulfide, reducing environmental pollution.
   • Organic Fertilizer Production: Converts manure into safe fertilizers, achieving a cycle of integrated farming and cultivation.