摘要
【目的】近年来,抗生素在畜禽及水产养殖中的使用量增加,导致固体废弃物和污水中存在大量的抗生素和耐药菌。土霉素作为用于养殖业主要的抗生素之一,在畜禽粪便和污水中的残留含量较高,因此,筛选并鉴定了能降解残留土霉素的微生物。【方法】采用富集驯化法,以菌肥、药渣和畜禽粪便为原料,采用摇床震荡的方法进行微生物培养,采用高效液相色谱法(HPLC)进行土霉素含量测定,筛选出能够高效降解土霉素的微生物。本研究还对降解菌在不同温度、p H、转速和接种量条件下的土霉素降解效果进行优化,并最终利用16S r DNA的方法鉴定菌种。【结果】筛选出一株能够高效降解土霉素的菌株T4菌,经16S r DNA测序鉴定该菌株为假单胞菌(Pseudomonas sp.),该菌株在30℃时对土霉素的降解率最高,达到了26.75%;不同p H梯度下,T4菌在p H为7时对土霉素的降解率达到最高,为27.03%;转速为150 rpm和170 rpm时,T4菌对土霉素的降解率分别为26.18%和25.59%,考虑到摇床高转速耗能高的因素,因此选择150 rpm为优化的转速;接种量对T4菌降解土霉素的影响较小,而且二者之间呈负相关,接种量1%时降解率最高,为26.88%。优化条件下,T4菌对100 mg/L土霉素的降解率为26.29%;堆肥试验表明,添加了T4菌之后,土霉素去除率更高,为93.21%。【结论】本研究筛选出的菌株T4对土霉素有较好的降解能力。通过16S r DNA基因序列分析,T4菌属于假单胞菌(Pseudomonas sp.),其降解土霉素的优化条件为温度30℃、p H 7.0、转速150 rpm、接种量1%。在堆肥中接种T4菌后,提高了对土霉素的去除作用,表明T4菌作为土霉素降解菌具有污染治理的潜力。
【Objectives】With the rapid development of intensive livestock breeding, the use of antibiotics has been increased sharply, which results in a large amount of antibiotics residuals and drug-resistant bacteria in solid waste and sewage. The improper discharge of these solid waste and sewage leads to accumulation of antibiotics and drug-resistant bacteria in soil and water. As one of the main antibiotics used in animal husbandry industry,high residual content of oxytetracycline exists in animal manure and sewage. Effective strains need to be developed for the efficient degradation and cleanup of residual oxytetracycline. 【Methods】A method of enrichment and acclimation was applied to screen oxytetracycline degradation bacteria from microbial fertilizers,antibiotic fermentation residues and livestock manures. The screened strains were identified using the 16 S r DNA sequencing technology. Oxytetracycline content was determined using high performance liquid chromatography（HPLC） method. The biodegradation condition of oxytetracycline by the screened bacteria was optimized under different temperature, p H, rotation speed and inoculum size. 【Results】The screened strain of T4 was found capable of efficiently degrading oxytetracycline, and was identified as Pseudomonas sp. The degradation rate of oxytetracycline was the highest（26.75%） at 30℃, and was 27.03% at p H 7. When the rotation speed was 150 rpm and 170 rpm, oxytetracycline showed higher degradation rates of 26.18% and 25.59%, respectively. Considering the high energy consumption of the high-speed shaking, 150 rpm was chosen as the optimal speed. The inoculation was negatively correlated with the degradation of oxytetracycline, and finally 1% of inoculum size was chosen as the optimized one. The highest oxytetracycline degradation rate was 26.29% under the final optimized condition at the medium of 100 mg/L oxytetracycline. In addition, the composting experiment showed that T4 could effectively improve the degradation of oxytetracycline during
作者
孟应宏
冯瑶
黎晓峰
刘元望
李兆君
MENG Ying-hong;FENG Yao;LI Xiao-feng;LIU Yuan-wang;LI Zhao-jun(College of Agriculture, Guangxi University, Nanning 530004, China;Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/Ministry of Agriculture Key Laboratory of Plant Nutrition and Fertilizer, Beijing 100081, China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2018年第3期720-727,共8页
Journal of Plant Nutrition and Fertilizers
基金
国家重点研发计划(2016YFD0800603)
河北省科技项目(15227504D)资助
关键词
土霉素
降解菌
筛选
降解特性
oxytetracycline
degrading bacteria
isolation
degradation characteristics
