Chloramphenicol (CAP) is a popular antibiotic used to fight bacterial infections in humans and animals. It’s so popular, in fact, that CAP can build up to levels that threaten entire ecosystems and promote the spread of antibiotic resistance genes. One way to prevent this buildup is to understand and exploit how microbes naturally degrade CAP. To that end, researchers explored the biotransformation pathways carved by a community of microbes fed solely on CAP for 1.5 years. Metagenomics identified 18 distinct groups of microbes in the community, the most dominant being Sphingomonas, which are bacteria known for, among other things, their ability to survive with little nutrients. In the lab, these bacteria were found to degrade 120 mg/L of CAP in 48 hours. Analyzing the collective functions of genes expressed by CAP degraders revealed a series of biotransformation pathways spanning six catabolic modules. The isomerization at the C₃-OH in particular represents an entirely new pathway of CAP degradation. Understanding how this collection of microbes degrades CAP is important, as it could lead to effective means for reducing harmful CAP levels in wastewater from hospitals, pharmaceutical companies, and livestock breeding grounds.