通过实验研究了堆肥生产过程中,菌剂添加对鸡粪高温堆肥中四环素类抗生素(四环素和土霉素)降解、四环素抗性细菌和致病菌(大肠菌群和沙门氏菌)的影响。结果表明,菌剂添加可以提高鸡粪堆肥的高温期温度,促进肥料腐熟,并且能够提高土霉素的降解速率。实验组原料中76μg·kg-1的土霉素经过高温堆肥得到有效去除,而不接种菌剂的对照组中土霉素没有明显去除;原料中沙门氏菌在堆肥起始阶段(8 d)就能够杀灭,而大肠菌群一直持续检出,直到堆肥末期(47 d)才小于2 lg CFU·g-1。抗四环素细菌在堆肥过程中的数量总体呈下降趋势,堆肥成品分别比原料减少1.41 lg CFU·g-1(实验组)和1.60 lg CFU·g-1(对照组),抗性细菌占总菌数的比例呈现先上升再下降的趋势,最终比例分别为4.00%(实验组)和1.17%(对照组),均高于原料的抗性菌比例(0.40%和0.39%)。
Veterinary antibiotics are widely used as feed additives in livestock breeding for growth promotion and disease prevention. Composting may provide a practical and economical solution for reducing the risks of antibiotic pollution to the environment. A pilot field study was conducted to investigate the changes of antibiotics [tetracycline(TC) and oxytetracycline(OTC)] and tetracycline-resistant bacteria(TRB)during composting of chicken manure mixed with goat manure. Results showed that both temperature and degradation rates of OTC were higher in the manure inoculated with microbial composting agents(CA)than that without microbial agents(CK). The content of residual OTC in the manure decreased from 76 μg·kg-1to below the detectable limit after 47 day of composting. However, OTC content in CK did not change during composting. Tetracycline(TC) disappeared rapidly in both CA and CK 17-days after composting. Salmonella in the manure were killed in both CA and CK treatments within 8 days, whereas coliforms were continuously detected until the 47 th day. Over the47-day composting, TRB decreased by 1.41 lg CFU·g-1in CA and 1.60 lg CFU·g-1in CK, compared to the initial. However, the proportion of TRB to total bacteria increased at beginning and then declined, but the TRB proportion was still 4.00%(CA)and 1.17%(CK)higher at the end than at the beginning.
Journal of Agro-Environment Science( J. Agro-Environ. Sci.)