MYCOLab Ai Logo - gold and army green

Nitrile rubber biodegradation by Gordonia sp. strain J1A and discovery of an oxygenase involved in its degradation

Summary

Scientists discovered a bacterium called Gordonia that can break down nitrile rubber, a common plastic used in gloves and seals. The bacterium produces a special enzyme that cuts the polymer chains into smaller pieces. This finding could lead to new methods for recycling rubber waste instead of burning it, addressing a growing environmental problem as millions of tons of rubber products are discarded each year.

Background

Acrylonitrile-butadiene rubber (NBR) is a widely used petroleum-derived synthetic polymer in disposable gloves and oil seals, with most waste materials being incinerated rather than reused. Large quantities of waste NBR are generated globally, with Japan alone producing approximately 0.1 Mt/yr. The development of bio-upcycling methods for waste NBR requires identification of microorganisms capable of assimilating this polymer.

Objective

To isolate NBR-degrading microorganisms from industrial wastewater treatment systems and identify the enzymatic mechanisms involved in NBR degradation. The study aimed to characterize the degradation pathways and key enzymes responsible for cleaving the carbon-carbon bonds in NBR polymers.

Results

Gordonia sp. strain J1A degraded 6.5-11% of waste NBR by weight in 10 days. A membrane-bound nitrile rubber oxygenase (Nro1) was identified as a key enzyme catalyzing the initial degradation step. The enzyme cleaved main-chain C-C and C=C bonds, producing degradation products including 4-cyano-1-cyclohexene and C22-C58 NBR oligomers with aldehyde, ester, and hydroxyl groups.

Conclusion

The discovery of Nro1, a novel oxygenase belonging to the MpaB family proteins, represents a significant advancement in understanding enzymatic degradation of synthetic polymers. The identified degradation pathway and products provide a foundation for developing bio-upcycling strategies for waste NBR, with potential applications in polymer recycling and waste management.
  • Published in:Applied and Environmental Microbiology,
  • Study Type:Experimental Study,
  • Source: 10.1128/aem.02128-25, 41294349
Scroll to Top