Effect of bioaugmentation on lignocellulose degradation and antibiotic resistance genes removal during biogas residues composting.

In this study, six strains belonging to Alcaligenes, Enterobacter and Bacillus were employed to enhance the composting process of biogas residues and agricultural wastes. The dynamic changes of dissolved organic matter (DOM), microbial community and functional genes in composting was monitored. It was found bioaugmentation reduced the content of lignocellulose in the compost by 27.14-66.30%, and increased the seed germination index (GI) of the compost by 37.59%. Metagenomics analysis of the composting process indicated Proteobacteria (35.38%-64.19%), Actinobacteria (11.24%-28.93%) and Bacteroidetes (3.65%-9.57%) are the dominant microorganisms during the bioaugmented composting. The abundance of genes associated with glycoside hydrolase was obviously enhanced and the antibiotic resistance genes (ARGs) was significantly reduced during the bioaugmented composting. Following nursery investigation indicated the seedling substrates composed of bioaugmented compost increased the dry weight of tomato seedlings by 1.7 times, revealing obvious large-scale application potential in the resource utilization of agricultural wastes.