Screening and degradation characteristics of oxytetracycline degrading bacteria
Oxytetracycline,a widely used,cheap,broad-spectrum antibiotic,was selected as the target pollutant to screen out strains of bacteria with a high ability to degrade oxytetracycline and explore their degradation characteristics.This study identified two strains capable of degrading oxytetracycline and analyzed their morphology,physiological,and biochemical characteristics and DNA sequencing of two strains.The degradation performance was investigated under different strain mix ratios,inoculation amounts,initial concentrations,pH,temperature,and additional carbon and nitrogen sources.The results indicate that the two strains were Escherichia and Bacillus sp.Both strains could grow in an inorganic salt medium with oxytetracycline as the only carbon source.The results showed that the degradation rate was the highest when the initial concentration of oxytetracycline was 65 mg·L-1,the mixed inoculation ratio was 1∶1,the inoculation amount was 3%,the pH was 5,the temperature was 35℃,the added carbon source was maltose,and the added nitrogen source was sodium nitrate.The highest degradation rate was obtained when carbon and nitrogen sources were added.Four potential degradation pathways of oxytetracycline were found.The main degradation processes were benzene ring cleavage,dehydrogenation,dehydration,decarbonylation,demethylation,dehydroxylation,deamination,and deamidation.The two bacteria were capable of degrading oxytetracycline in the environment effectively,which merits further investigation and has potential,in application,to degrade and remove oxytetracycline from animal manure and farm soil.
万方数据
维普
