Effect of biochar addition on the dynamics of antibiotic resistant bacteria during the pig manure composting

In present study, the taxonomic variation of antibiotic resistant bacteria (ARB) in pig manure (PM) composting with coconut shell biochar (CSB) and bamboo biochar (BE) addition was investigated. The experiment was divided into three treatments: T1 (as control or without biochar amendment), T2 was added 10% coconut shell biochar and T3 supplemented with 10% bamboo biochar. The initial feed stock were properly homogenized using a mechanical crusher. PM and wheat straw (INS) were mixed in a 5: 1 dry weight ratio to adjust the initial carbon/nitrogen ratio 25:1, bulk density to similar to 0.5 (kg/L) and similar to 60% moisture content, respectively. This experiment was lasted for 42 days. The results indicated the bacterial communities in the three treatments were more different in terms of relative abundance and diversity of dominant bacteria. The control group had the highest abundance of Kingdome bacteria. The changes in ARE was noticed by variation in the relative abundances of Actinobacteria, Pmtsobacteria, Firrnicutes and Bacteroidota. At the cnd of composting (on day 42), the total RAs of ARB at the class, order, and family levels were considerably reduced in T2 and T3 by similar to 35.78-38.75%, 36.42-40.63% and 45.82-47.70%, respectively. But in T1 was decreased by 6.16-8.62%, 7.93-8.72% and 8.70-10.15%, as compared with the day 0 sample. However, the CSR was much more effective to reduce 55 to 60% of ARE than T3 or BB applied treatment has 40 to 42% ARE reduction, while control has certainly very less RAa of ARE reduction. Finally, the biochar amendment was significant approach to mitigate the total ARE abundance in compost and it's further used for organic farming purposes.

Automated summary

The study investigated the taxonomic variation of antibiotic resistant bacteria in pig manure composting with coconut shell biochar and bamboo biochar. The results showed that the addition of biochar significantly reduced the total abundance of antibiotic resistant bacteria in compost, with different treatments showing varied effects on the bacterial communities.