Isolation and screening of quinoline-degrading bacteria and their biodegradation capability in the digestive tract of camels

Camels can eat poisonous plants with a strong odor which other animals can't eat,without affecting the normal physiological metabolism.The studies show that the plant toxin that the camels gather from the food has similar chemical structures with quinoline heterocyclic compounds,so it is of great significance that whether there are potential heterocyclic compounds degrading bacteria in the camel body.Gastrointestinal contents were collected from three camels' rumens and guts,enrichment culture was applied for five generations by using quinoline as sole carbon source and nitrogen source.High throughput sequencing (Illumina MiSeq) was used to sequence the 16S rDNA PCR of microorganisms from the five dynasties enrichment and isolate culture.17 strains of microorganisms for degrading Quinoline were isolated,and the dominant species was Bacillus and Ochrobactrum,which took 77.78% and 17.60%,respectively.There were two degrading bacteria strains,K3,K38,degrading 66.79% and 66.20% of quinoline,respectively within 132 hours,which shows strong degradation ability in the experiments.Inoculum size shows the greatest effect in four kinds of environment factors in the experiment for K3,and the second is the temperature,then initial pH,and the carbon source.The best experimental condition is the temperature of 37℃,inoculum size of 15%,initial pH 7.0,5g carbon source.