Field tests of crop growth using hydrothermal and spray-dried cephalosporin mycelia dregs as amendments: Utilization of nutrient and soil antibiotic resistome

The disposal and reuse of cephalosporin mycelia dregs (CMDs) pose a great challenge to the biopharma industry, but it acts as the new source of antibiotic resistome, although agriculture intensification remains uncertain. Herein, two common cash crops (maize and soybean) were planted in the actual field, and the effects of the application of treated CMDs, chicken manure and chemical fertilizer served as control groups were both investigated according to comparison experiment. Amplicon-targeted 16S rRNA and high-throughput sequencing was analyzed for rhizosphere antibiotic resistome. Results showed that hydrothermal and spray-dried (HT + SD) CMDs could promote nutrients uptake and stabilize soil fertility indicator, and finally improved the crop yield (maximum, 119.68%). The numbers and relative abundances of total ARGs in soils were not significantly different from that of conventional fertilizer (p ＞ 0.05), but crop type marked the differences in distribution. The overall economic benefits are predicted to be around $373-745 million annually, considering its application to the whole country. HT + SD-treated CMDs can be therefore used as a high-quality and safe alternative fertilizer for agriculture use. These findings are expected to offer a fresh perspective on the application of antibiotic fermentation residue (AFR) in the future.