Researchers Turn Milling Waste into Nutrient-Rich Agricultural Inputs Through Microbial Fermentation

Researchers at Mendel University in Czech Republic have developed a quicker method to convert low-value cereal milling waste into nutrient-rich biofertilizers. Cereal processing generates vast amounts of waste in the form of wheat bran, flour, and milling dust that are difficult to process and traditionally take months to break down through standard composting. To solve this, the team paired enzyme treatment with controlled bacterial fermentation to speed up breakdown. In just three days, this microbially driven process effectively breaks down tough plant fibers, turning underutilized industrial side-streams into valuable agricultural inputs.

The grain milling wastes were subjected to a 24-hour enzymatic treatment using xylanase, combined with a 48-hour bacterial fermentation using Lactiplantibacillus plantarum and Bacillus subtilis. The findings reveal that the fermentation process lowered pH levels and triggered organic acid chelation. Subsequent laboratory analyses confirmed that total protein was doubled, lactic acid was increased by 6.5 times, and free phosphorus was doubled compared to raw waste. Soluble concentrations of key microelements, such as calcium, iron, magnesium, manganese, and zinc, were also significantly increased, thereby creating an enriched bio-input ready for crop application.

Greenhouse tests on corn showed that applying this fermented waste into the soil or as a liquid drench gave plants significantly more usable nitrogen than standard compost. The plants grew healthy green leaves and took up high amounts of essential minerals like magnesium and zinc. While the test cannot completely replace synthetic NPK fertilizers, it gives farmers a practical, natural tool to boost soil health and crop nutrition.

Read the full study in Frontiers in Sustainability for more information.