Effects of passivators on antibiotic resistance genes and related mechanisms during composting of copper-enriched pig manure

Biochar can mitigate co-selection and control antibiotic resistant genes (ARGs) in compost and soil

“…In pig manure composting, 12% dose of wheat biochar and rice straw biochar immobilised Cu and Zn ( Awasthi et al., 2020c ). In similar studies, 10% biochar dose, passivated and reduced the BF of Zn, Cu, Cd, and Pb with a greater effect on Cu and Pb ( Cui et al., 2020b ; Duan et al., 2021 ; Hao et al., 2019 ; Li et al., 2017 ; Qian et al., 2019 ). The bacterial diversity was increased and altered at thermophilic phase, and the effect of bacterial on metal passivation was dependent of C:N ratio ( Song et al., 2021 ).…”

“…Biochar have been reported to enhance the effectiveness of biowastes composting and to improve the quality of the final product ( Chavez-Garcia et al., 2020 ; Godlewska et al., 2017 ; Liu et al., 2017 ; Pandiyan et al., 2021 ; Teodoro et al., 2020 ; Wang and Zeng, 2018 ; Wu et al., 2017b ; Xiao et al., 2017 ; Yin et al., 2021 ; Zhang et al., 2021c ). Biochar has been shown in literature to reduce gaseous emissions ( Awasthi et al., 2017 , 2020a ), reduce N and C losses ( Awasthi et al., 2020b ; Zhang et al., 2021a ), reduce composting duration ( Qu et al., 2020 ), increase humification ( Vandecasteele et al., 2014 ; Jindo et al., 2016 ), improve aeration and porosity ( Zhang et al., 2014 ), reduce bioavailable HMs fraction ( Cui et al., 2020b ), reduce ARGs ( Qian et al., 2019 ; Cui et al., 2016a , 2016b ), improve microbial activity ( Awasthi et al., 2020b ; Lia et al., 2020 ; Qu et al., 2020 ), improve available nutrient ( Zainudin et al., 2020 ; Wei et al., 2021 ), and reduce ecotoxicity in compost ( Wang et al., 2017 ).…”

“…Temperature was reported as the most influencing environmental parameter controlling ARGs abundance and distribution during Chicken manure composting followed by C:N ratio and pH. Biochar reduced the abundance of MGEs and ARGs in pig manure composting with no effect on copper resistance genes, indicating that removal of co-selection pressure may not always be a factor in all ARGs reduction in composting ( Qian et al., 2019 ). Variation and shift in microbial community/structure explained the changes observed in MGEs and ARGs in the study.…”

“…(2017) Apple tree branches Pig manure & wheat straw; 5:3 w/w 10 dwt 550 NA 40 Biochar addition reduced ARGs (tetC, ​tetG, ​tetQ, ​tetX, ​sul1, and ​ermB) by 0.23–1.09 logs, MGEs (intI1 & ISCR1) by 26–85%, and intI2 ​& Tn914/1545. Qian et al. (2019) Maize straw Sewage sludge & maize straw 3:2 v/v 5 400 8 40 Biochar reduced ARGs by 17.6%.…”

Environmental effects and risk control of antibiotic resistance genes in the organic solid waste aerobic composting system: A review

“…These changes in the microenvironment could indirectly affect the changes in ARGs as it affects microorganisms and MGEs. Qian et al (2019) added biochar, fly ash, and zeolite to promote ARG removal in pig manure compost. In this study, changes in the bacterial community determined the changes in the abundances of ARGs as demonstrated by redundancy analysis.…”