Tong Zhenye, Liu Fenwu, Tian Yu, Zhang Jingzhi, Liu Hui, Duan Jiaze, Bi Wenlong, Qin Junmei, Xu Shaozu
College of Resources and Environment, Shanxi Agricultural University, Jinzhong, China.
Nongshengyuan Family Farm, Jinzhong, China.
Front Bioeng Biotechnol. 2022 Jul 22;10:960476. doi: 10.3389/fbioe.2022.960476. eCollection 2022.
Pig manure is a reservoir of antibiotics and antibiotic resistance genes (ARGs). The effect of biochar on the variations in physicochemical properties, bacterial communities, antibiotics, ARGs, and mobile genetic elements (MGEs) of compost product during co-composting of pig manure and corn straw have been investigated in this study. Compared with the control treatment (CK), biochar addition accelerated the increase in pile temperature and prolonged the high temperature period (>55°C) for 2 days. Under biochar influence, organic matter degradation, NH -N conversion and NO -N production was accelerated, and dissolved total organic carbon (DOC) and dissolved total nitrogen (DTN) utilization by microorganisms were enhanced. Biochar addition altered the microbial community and promoted the vital activity of in the later composting stage. The antibiotics removal efficiency (except danofloxacin and enrofloxacin) was accelerated in the early composting stage (1-14 days) by biochar addition, the pile temperature had a positive effect on antibiotics removal, and the total antibiotics removal efficiency in CK and CK+Biochar treatments was 69.58% and 78.67% at the end of the composting process, respectively. The absolute abundance of most of the ARGs in the CK+Biochar treatment was lower than that in the CK treatment during composting, and the ARGs removal mainly occurred in the early (1-14 days) and later (28-50 days) stages. Biochar addition reduced the absolute abundance of MGEs (, ) in the compost product, and most of the ARGs had a significant positive correlation with MGEs. Network analysis and redundancy analysis showed that ARGs and MGEs occurred in various host bacteria (, , , , and ), and that DTN and NH -N are the main factors regulating the changes in bacterial communities, antibiotics, ARGs, and MGEs during composting. Moreover, MGEs contributed the most to the variation in ARGs. In summary, biochar addition during composting accelerated antibiotics removal and inhibited accumulation and transmission of ARGs. The results of this study could provide theoretical and technical support for biochar application for antibiotics and ARGs removal during livestock and poultry manure composting.
猪粪是抗生素和抗生素抗性基因（ARGs）的储存库。本研究考察了生物炭对猪粪与玉米秸秆共堆肥过程中堆肥产品的理化性质、细菌群落、抗生素、ARGs和可移动遗传元件（MGEs）变化的影响。与对照处理（CK）相比，添加生物炭加速了堆体温度的升高，并使高温期（>55°C）延长了2天。在生物炭的影响下，有机质降解、NH₄⁺-N转化和NO₃⁻-N生成加速，微生物对溶解性总有机碳（DOC）和溶解性总氮（DTN）的利用增强。添加生物炭改变了微生物群落，并在堆肥后期促进了微生物的生命活动。在堆肥前期（1 - 14天），添加生物炭加速了抗生素的去除效率（除达氟沙星和恩诺沙星外），堆体温度对抗生素去除有积极作用，堆肥结束时CK和CK +生物炭处理中抗生素的总去除效率分别为69.58%和78.67%。在堆肥过程中，CK +生物炭处理中大多数ARGs的绝对丰度低于CK处理，ARGs的去除主要发生在前期（1 - 14天）和后期（28 - 50天）。添加生物炭降低了堆肥产品中MGEs（intI1、intI2）的绝对丰度，且大多数ARGs与MGEs呈显著正相关。网络分析和冗余分析表明，ARGs和MGEs存在于多种宿主细菌（Acinetobacter、Bacillus、Corynebacterium、Enterococcus和Staphylococcus）中，DTN和NH₄⁺-N是堆肥过程中调节细菌群落、抗生素、ARGs和MGEs变化的主要因素。此外，MGEs对ARGs变化的贡献最大。综上所述，堆肥过程中添加生物炭加速了抗生素的去除，并抑制了ARGs的积累和传播。本研究结果可为生物炭在畜禽粪便堆肥过程中去除抗生素和ARGs的应用提供理论和技术支持。
