耐冷四环素降解菌筛选及其在低温猪粪四环素降解中的初步应用  

Screening of psychrotrophic tetracycline degrading strain and its preliminary application of tetracycline degradation in pig manure under low temperature

作　　者：张硕 米耀族 芦健 臧海莲[1] 李春艳[1] ZHANG Shuo;MI Yaozu;LU Jian;ZANG Hailian;LI Chunyan(School of Resources and Environment,Northeast Agricultural University,Harbin 150030,China)

机构地区：[1]东北农业大学资源与环境学院,哈尔滨150030

出　　处：《东北农业大学学报》2024年第4期32-41,共10页Journal of Northeast Agricultural University

基　　金：黑龙江省自然科学基金重点项目(ZD2023D001)。

摘　　要：四环素是畜牧业常用抗生素,其广谱性和难以代谢性导致药物普遍残留在畜禽粪便中。于严寒地区生产四环素兽药厂采集排污口污泥,采用富集筛选方法分离到1株四环素降解细菌。根据菌株显微形态特性、生理生化特征及分子生物学鉴定,将该菌株鉴定为Serratia sp.ZS-8。在10℃条件下,将其置于以四环素(50 mg·L^(-1))为唯一碳源的无机盐培养基中,培养7 d后,四环素降解率可达63.9%(降解速率0.190 mg·L^(-1)·h^(-1))。通过PlackettBurman(PB)设计筛选影响四环素降解的主要因素,再通过Box-Behnken Design优化主要因素,得到最佳降解条件为:温度18.0℃、pH 7.0、底物浓度50 mg·L^(-1),接种量4.4%。最佳降解率达到65.2%,较未优化前提高2.03%。在环境温度为10℃条件下,将该菌株接种至猪粪中,30 d猪粪中四环素残留量由11.4 mg·kg^(-1)降低至3.84 mg·kg^(-1),降解率为64.5%,显著高于对照组(22.9%)。Tetracycline is a commonly used antibiotic in animal husbandry.Its broad spectrum and difficult metabolism lead to its widespread presence in animal manure.A tetracycline degrading strain was isolated from the sewage sludge of a tetracycline veterinary drug factory in severe cold area by enrichment screening method.According to the microscopic morphological characteristics,physiological and biochemical characteristics and molecular biological identification of the strain,it was identified as Serratia sp.ZS-8,and its tetracycline degradation rate could reach 63.9%(Degradation efficiency 0.190 mg·L^(-1)·h^(-1))in 7 days at 10℃.The main factors affecting the degradation of tetracycline were screened by Plackett-Burman(PB)Design,and then the main factors were optimized by Box Behnken Design.The optimal degradation conditions were obtained as follows:temperature 18.0℃,pH 7.0,substrate concentration 50 mg·L^(-1),inoculum size 4.4%,and the degradation rate was 65.2%,which was 2.03%higher than that before optimization.When the strain was inoculated into pig manure at 10℃,the tetracycline residue in pig manure decreased from 11.4 mg·kg^(-1) to 3.84 mg·kg^(-1) in 30 days,and the degradation rate was 64.5%,significantly higher compared with the control group(22.9%).

关 键 词：低温 耐冷四环素降解菌 降解条件优化 猪粪 

分 类 号：O513[理学—低温物理]