Chromium-Tanned Leather and Microbial Consortia: Identification of Taxa With Biodegradation Potential and Chromium Tolerance

Author: mycolabadmin
6/17/2025
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Summary

Leather waste from the tanning industry is difficult to break down and often ends up in landfills or incinerators. Scientists discovered that natural communities of bacteria found on decomposing leather can help break down chromium-tanned leather under simple nutrient conditions. These bacteria form protective biofilms and produce enzymes that gradually degrade the collagen in leather, offering a promising sustainable solution for managing leather waste.

Background

Chromium-tanned leather waste presents significant environmental challenges due to its resistance to degradation and heavy metal content. Chromium(III) salts account for approximately 90% of global leather production, forming stable cross-links with collagen that make the material highly resistant to microbial degradation. Large volumes of solid waste from leather manufacturing are typically disposed of via landfilling or incineration, contributing to long-term environmental contamination.

Objective

This study investigates the potential of naturally selected microbial consortia to initiate the degradation of chromium-tanned leather and identifies key bacterial genera capable of tolerating chromium and producing enzymes relevant to collagen breakdown. The research combines gravimetric assays, metagenomic sequencing, and scanning electron microscopy to characterize both microbial composition and degradation dynamics.

Results

Dominant genera including Bacillus, Microbacterium, and Acinetobacter were associated with collagen degradation and metal tolerance, with Bacillus-rich communities showing the most pronounced mass loss (up to 3%). SEM analysis revealed formation of robust biofilms and extensive matrix disruption, indicating enzymatic activity and structural breakdown of leather. Cultivable strains confirmed the presence of biotechnologically relevant genera such as Microbacterium, Brevibacterium, and Lysinibacillus.

Conclusion

Naturally derived microbial consortia can initiate the biodegradation of chromium-tanned leather under nutrient-limited conditions. The research demonstrates that key taxa form biofilms, tolerate chromium, and induce collagen matrix disruption, highlighting their potential for sustainable biotechnological applications in leather waste management. The findings support further development of biologically-based waste management strategies for the leather industry.

Published in:Environmental Microbiology Reports,
Study Type:Experimental Study,
Source: PMID: 40528698, DOI: 10.1111/1758-2229.70134