Bacillus and lactic acid bacteria inoculation to transform kitchen waste using Hermetia illucens

In this study, Bacillus mojavensis and Lactiplantibacillus herbarum were used to co-treat kitchen waste (KW) with Black soldier fly larvae (BSFL). The effects on the physicochemical properties, heavy metal content, and microbial community of the BSFL sand were determined. Compared to the control group, the L. herbarum inoculation reduced 19.04 % of the soluble salt (TSS), 15.48 % of Ni, and 13.04 % of Zn in the residues; the B. mojavensis inoculation reduced 23.84 % of TSS, 13.61 % of Pb, and 20.32 % of the Ni in the residues; the L. herbarum and B. mojavensis inoculation reduced 29.53 % of Cr, 20.23 % of Pb, 18.06 % of Ni, and 25.68 % of the Zn in the residues. The microbial inoculants significantly enhanced the BSFL sand microbial diversity (Tukey, P < 0.05). The dominant phylum and genus in the BSFL sand were Firmicutes (53.08 %) and Corynebacterium (47.01 %), respectively. The microbial inoculants resulted in an approximate 12 % reduction in Corynebacterium. The linear discriminant analysis effective size analysis showed that the Corynebacterium abundance was significantly reduced. The microbial inoculants significantly affected the Corynebacterium relative abundance by significantly altering the substrate TSS, moisture content, and Ni. In conclusion, the effect of B. mojavensis and L. herbarum on the BSFL treatment of KW was beneficial, and their potential should be further exploited.