氯霉素降解菌的分离筛选及降解性能研究

陈茂祥 夏灵恩 毛乐佳 傅文韬 许双燕 郑华宝

摘要 从施用由猪粪堆肥制成的有机肥的土壤中筛选、驯化出一株能以氯霉素为唯一碳源的降解菌。经形态学特征观察及16S rDNA序列分析，初步鉴定该菌株属于假单胞菌属（Pseudomonas sp.），命名为CAP_CXMF。通过控制单一变量探讨菌株的最佳生长条件以及不同外加碳氮源对降解菌降解率的影响。结果表明，在氯霉素初始浓度为300 mg/L、接种量10%、温度20 ℃、转速160 r/min、pH为7时，该菌株对氯霉素的降解率达72.55%，添加一定量的酵母膏和葡萄糖后的降解率分别为73.15%和72.80%。该菌株对氯霉素有良好的降解性能，可以用于治理环境中的氯霉素污染问题，并为生物降解抗生素提供一种新的优势菌株。

关键词 氯霉素;降解菌;分离筛选;降解性能

中图分类号 X172 文献标识码 A 文章编号 0517-6611（2021）09-0061-05

doi：10.3969/j.issn.0517-6611.2021.09.017

Abstract Isolating and screening a highly efficient chloramphenicol-degrading strain with chloramphenicol as the sole carbon source from soil applying organic fertilizer made from pig manure compost. The strain named as CAP_CXMF was initially identified as Pseudomonas sp. by morphological observation and 16S rDNA sequence analysis. The growth and the degradation of CAP were investigated in this research. The results showed that the chloramphenicol degradation rate with the initial concentration of 300 mg/L， the inoculation amount was 10%， the temperature was 20 ℃， the rotation speed was 160 r/min， and the pH was 7， reached 72.55%. The strain had a high degradation efficiency and the degradation rate after adding yeast extract was 73.15%， as well as adding glucose was 72.80%. Due to its good degradation performance， it could be used for the treatment of chloramphenicol antibiotic pollution， providing a new dominant strain for the biological treatment of chloramphenicol.

Key words Chloramphenicol;Degrading strain;Isolation and screening;Degradation property

目前，抗生素的濫用尤其是在畜牧业中的滥用已成为重要的环境问题[1]。2013年，抗生素在畜牧业中的使用量占总使用量的50%以上，已经高于在人类中的使用量[2]。因此，2016年9月G20杭州峰会提出谨慎使用抗生素并考虑抗生素在可负担和可获得性上所面临的挑战和对公共卫生的影响[3]。氯霉素（chloramphenicol，CAP）作为一种广谱抗生素，近年来广泛应用于畜牧业中畜禽的疾病控制和治疗方面[4]。氯霉素在水产、畜牧业中使用后，会随着畜禽粪便的排放以及生产氯霉素类药物废水的排放进入环境，导致大量氯霉素残留在环境中，容易造成环境风险[5]。氯霉素注射进入家畜后容易在其体内残留，之后体内残留有氯霉素的家畜被人类食用，会随之进入人体，残留在人体内的氯霉素会引起人体再生障碍性贫血对人类健康产生极大的威胁[6-7]。……