Effects of bamboo charcoal on antibiotic resistance genes during chicken manure composting

Publication date: June 2017
Source:Ecotoxicology and Environmental Safety, Volume 140
Author(s): Haichao Li, Manli Duan, Jie Gu, Yajun Zhang, Xun Qian, Jun Ma, Ranran Zhang, Xiaojuan Wang
Composting is widely used for animal waste disposal, and bamboo charcoal (BC) can be used for nitrogen conservation during composting. However, the effects of BC on antibiotic resistance genes (ARGs) during chicken manure composting are still unclear. This study investigated the effects on ARGs of adding different proportions of BC (0%, 5%, 10%, and 20% w/w) to chicken manure compost. After 26 days, the relative abundances (RAs) of most ARGs (tetC, tetG, tetW, tetX, sul2, drfA1, drfA7, ermB, ermF, ermQ, and ermX) and intI1 declined by 21.6–99.5%, whereas sul1 increased by 7.5–17.7 times. The average RAs reductions with 0%, 5%, 10%, and 20% BC were 0.85, 1.05, 1.08, and 1.15 logs, respectively. The most important environmental factor for the ARG profiles was temperature according to redundancy analysis. Furthermore, BC significantly decreased the bio-Cu and bio-Zn levels, thereby reducing the co-selection pressure from heavy metals. Different proportions of BC had no significant effects on the removal of tetG, tetW, tetX, sul2, drfA1, and ermB. Supplementation with 10% BC was more effective at removing tetC and drfA7 compared with the other treatments. The results suggested that 10% BC supplementation is appropriate for reducing ARGs in chicken manure compost.

Graphical abstract

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