# Microorganisms in the rumen and intestine of camels have the ability to degrade 2‐amino‐3‐methylimidazo[4, 5‐f]quinoline

## TL;DR

Camels' gut microbes can break down a harmful food toxin called IQ, which could help in developing ways to reduce cancer-causing compounds in food.

## Contribution

This is the first study to isolate IQ-degrading bacteria from camels' digestive systems and characterize their degradation abilities.

## Key findings

- Proteobacteria was the most abundant phylum in camel rumen and intestinal microbes after three generations of IQ cultivation.
- Four bacterial strains showed high IQ degradation rates, with Ochrobactrum and Pseudomonas being the most effective genera.
- The study identified 50 bacterial strains from camel digestive systems, providing potential resources for biodegrading food toxins.

## Abstract

Heterocyclic amines (HAs) are a group of mutagenic and carcinogenic compounds produced from the processing of high‐protein foods, which include 2‐amino‐3‐methylimidazo[4, 5‐f]quinoline (IQ) showing the strongest carcinogenic effect. Camels are able to digest HAs in foods, which provide rich microbial resources for the study. Thus, camel rumen and intestinal microbiota were used to degrade IQ, and the dominant microorganisms and their degradation characteristics were investigated. After three generations of culture with IQ as the sole carbon source, the highest abundance in rumen and intestinal microbes was found in the Proteobacteria phylum. The strains of third generation of the rumen contents were mainly attributed to the genera Brevundimonas and Pseudomonas, and the dominant genera in intestine were Ochrobactrum, Bacillus, and Pseudomonas. Microorganisms were further isolated and purified from the third generation cultures. These 27 strains from the rumen (L1–L27) and 23 strains from the intestine (C1–C23) were obtained. Among them, four strains with the most effective degrading abilities were as follows: L6 (28.55% of IQ degrading rate) and C1 (25.19%) belonged to the genus Ochrobactrum, L15 (23.41%) belonged to the genus Pseudomonas, and C16 (20.89%) were of the genus Bacillus. This study suggested the application of abundant microbial resources from camels' digestive tract to biodegrade foodborne toxins.

This work was the first to obtain IQ‐degrading bacteria from digestive tract of camels and to reveal the characteristics of these degrading bacteria. Results provided microbial resources for biodegradation of foodborne toxins.