Microbial agents assisted aerobic co-composting of sheep manure and furfural residue: Maturation enhancement and microbial dynamic

Abstract

The effects of different proportions of sheep manure (SM) and furfural residue (FR) and adding microbial agents (MA) on compost maturity, substance transformation and bacterial-fungal communities were investigated. Four groups were designed with low FR ratio groups (13SM+FR, 13SM+FR+MA) and high FR ratio groups (SM+FR+MA, SM+FR), among them, SM+FR+MA and 13SM+FR+MA both added 0.4 % MA. The results showed that after 30-days pile composting, all groups met the requirements for compost maturity, indicating that the combined composting of FR and SM were feasible. High FR ratios and the addition of MA can significantly enhance the temperature and prolong the thermophilic phase during the composting process. The high FR ratios were more conducive to the decomposition of organic matter (OM) and compost maturity. Adding MA promotes the metabolism and transformation of carbohydrates and proteins by altering the activity of enzymes in the thermophilic phase, while weakening pathways such as biosynthesis of secondary metabolites and carbon metabolism during the cooling maturation phase. In contrast to adding MA, adjusting the proportion of raw materials were easier and more effective to reshape the microbial communities in composting. In addition, composting significantly reduce the abundance of pathogens such as Rhodotorula, Exophiala, Scythalidium, and Lecythophora. Therefore, during the composting process, FR can be directly used as a conditioner for composting, adding MA and a higher proportion of FR to increase C/N ratio are effective strategies for inhibiting pathogens and enhancing compost maturity.