New Korean Fermented-Food Bacteria Breakthrough Offers Faster, Cleaner Food-Waste Decomposition

New Research Finds Powerful Food-Waste-Degrading Bacillus in Korean Fermented Foods

A new study published in Biodegradation (2025) has identified highly efficient Bacillus strains isolated from Korean fermented foods that can significantly accelerate food-waste decomposition. The work introduces a simplified enzyme-activity screening method that avoids costly enzyme purification steps while enabling rapid identification of high-performing microbes.

A Simpler Way to Measure Microbial Enzyme Activity

Traditional enzyme-activity assays typically require enzyme extraction and purification, a process that is time-consuming and expensive. The researchers evaluated multiple measurement approaches and developed a direct testing strategy using both agar plate assays and liquid cultures that measure reaction products—such as reducing sugars and amino acids—without purification.

This streamlined screening method allowed the team to analyze 56 Bacillus isolates sourced from fermented foods including jeotgal (fermented seafood) and jang (fermented soybean products).

Six Superior Strains Form a High-Performance Composite Culture

Among the isolates, six strains displayed exceptional amylase, protease, and cellulase activities on both solid and liquid media. These strains—all belonging to the genus Bacillus—were combined to produce a powerful mixed culture named composite-FSEL. 16S rRNA phylogenetic analysis confirmed that the selected isolates primarily matched Bacillus subtilis and Bacillus licheniformis, species well known for their thermostable and robust hydrolytic enzymes.

Outperforming Commercial Microbial Preparations

When compared with four commercially available microbial products, composite-FSEL showed:

Larger enzymatic clear zones on agar plates
Higher amylase, protease, and cellulase activity in liquid assays
Stronger degradation of standard food waste at 45 °C

Notably, composite-FSEL achieved:

>12% reduction in food-waste volume by Day 3,
Nearly 16% reduction by Day 7,
outperforming the best commercial preparation throughout the experiment.

A Scalable Solution for Sustainable Waste Management

By validating a simplified assay that preserves enzyme activity within intact cultures, this study provides a cost-effective toolkit for industrial microbial screening. The identification of a high-efficiency Bacillus consortium offers strong potential for improving on-site food-waste degradation technologies, especially in thermophilic systems operating at ≥45 °C.

The findings highlight how traditional fermented foods—long valued for their microbial diversity—may also serve as powerful sources of industrial biodegradation agents.

Reference

Im, YJ., Ryu, JW., Lee, J.H. et al. Simplified enzyme activity-based screening of microorganisms from Korean fermented foods for food-waste decomposition. Biodegradation 36, 109 (2025). https://doi.org/10.1007/s10532-025-10206-5