Soybean isoflavones and flavonoids of Artemisia argyi enhanced conversion of chicken manure by black soldier fly (Hermetia illucens L.) larvae and effects on microbiota of their larvae and residues

Abstract

Black soldier fly composting technology is a promising technology for the recovery of nutrients from organic waste and a hot spot in the research field of animal manure resource utilization, the co-transformation of microorganisms is not obvious in practical application, which limits the development of composting technology and results in the limited value of its products, therefore, plant flavonoids, which may have the effect of promoting the transformation of larvae, were selected as additives to promote the transformation of black soldier fly. In this study, the promoting effect of soybean isoflavones and flavonoids of Artemisia argyi on the conversion of black soldier fly was demonstrated, the important factors (larvae weight, total nitrogen, crude protein, conversion rate) in the composting system were determined and the changes in the microbial community structure during the composting process were clarified. The results have shown that 40 mg/kg soybean isoflavones and flavonoids of Artemisia argyi could significantly improve the larvae weight, and the black soldier fly larvae treated by 20 mg/kg flavonoids of Artemisia argyi could dramatically improve the conversion efficiency of crude protein in chicken manure (p < 0.05). Soybean isoflavones flavonoids and flavonoids of Artemisia argyi could significantly change the microbiota composition of residues (p < 0.05), while had no significant effect on the larvae microbiota. Soybean isoflavones flavonoids might promote the conversion of crude protein in chicken manure by the black soldier fly larvae through regulating their intestinal microbiota. The study provided reference data for using the flavonoids of Artemisia argyi to promote crude protein transformation of black soldier fly larvae from chicken manure as feed protein substitute.