Study on Isolation,Identification and Degradation Characteristics of Chloramphenicol Degrading Bacteria
This study focuses on screening out the microorganisms that can degrade chloramphenicol efficiently and analyzing their degradation characteristics.The Paphia undulata with high chloramphenicol residue was cultured and domesticated.The target bacteria was screened and separated by nutrient agar plate containing chloramphenicol.In this research,a microscope was used to ob-serve morphology of the target bacteria;a fully automatic microbial analysis system was adopted to conduct biochemical identification of the target strains;and bacterial 16S rDNA sequencing was used to identify the target strains.The content of chloramphenicol in samples or reactants was determined by high performance liquid chromatography tandem mass spectrometry.The degradation charac-teristics were studied under different reaction time,temperature,pH,substrate concentration and bacterial suspension content.A strain named SA-cd1,which can degrade chloramphenicol efficiently,was obtained by domestication and isolation.The bacteria was identi-fied as Shewanella algae according to its morphological characteristics,physiological and biochemical characteristics and 16S rDNA sequencing.The optimal temperature and pH for chloramphenicol degradation of SA-cd1 was 36-50℃and 6.0-9.0.The degradation rate of 0.1 mg/L chloramphenicol in 5 min reached 83.8%,and rose with the increase of the concentration of the bacterial suspension or the reaction time.The degradation rate did not decrease significantly with the increase of the substrate concentration,and the degra-dation rate of 10 mg/L chloramphenicol in 1 h was 92.5%.The supernatant after the removal of bacteria still had a strong degradation rate of 47.3%.SA-cd1 is easy to isolate and culture,with high degradation efficiency to chloramphenicol,as well as a wide range of suitable temperature and pH conditions,thus it can be applied to the degradation and removal of chloramphenicol in the environment,as well as the development of related degradation engineering bacteria and enzymes.
domestication and screeningShewanella algaebiodegradationpurification technology
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