Black soldier fly pretreatment promotes humification and phosphorus activation during food waste composting.

Black soldier fly (BSF) and thermophilic composting (TC) treatments are commonly adopted to manage food waste. In this study, 30 days of TC of food waste following seven days BSF pretreatment (BC) was compared to 37 days of TC of food waste (TC, the control). Fluorescence spectrum and 16S rRNA high-throughput sequencing analysis were used to compare the BC and TC treatments. Results showed that BC could decrease protein-like substances and increase humus substances more quickly, and that the humification index of compost products was 106.8% higher than that of TC, suggesting that the humification process was accelerated by BSF pretreatment resulting in a 21.6% shorter maturity time. Meanwhile, the concentrations of total and available phosphorus rose from 7.2 and 3.3 g kg-1 to 44.2 and 5.5 g kg-1, respectively, which were 90.5% and 118.8% higher in compost products from BC as compared to those in TC. Furthermore, BC had higher richness and diversity of humus synthesis and phosphate-solubilizing bacteria (PSB), with Nocardiopsis (53.8%) and Pseudomonas (47.0%) being the dominant PSB. Correlation analysis demonstrated that the introduction of BSF gut bacteria contributed to the effectiveness of related functional bacteria, resulting in a rapid humification process and phosphorus activation. Our findings advance understanding of the humification process and provide novel perspectives on food waste management.

Sequencing of complete mitochondrial genome of sword prawn Parapenaeopsis hardwickii (Miers) (Crustacea, Decapoda, Penaeidae).

The sword prawn Parapenaeopsis hardwickii (Miers) (Crustacea, Decapoda, Penaeidae) is an important commercial fishery species, distributed in the East China Sea. In this study, we described the complete mitochondrial genome of P. hardwickii. The genome is 15,922 bp in length, encoding the standard set of 13 protein-coding genes, 22 tRNA genes and two rRNA genes, with circular organization. The overall A + T content is 67.20%; nucleotide frequency of the gene is as follows: A, 35.01%; C, 20.83%; G, 11.98%; T, 32.19%. The gene order of P. hardwickii is the same as Penaeus monodon and Fenneropenaeus chinensis, and it mainly retains as the Penaeidae ground pattern. The complete mitogenome sequence information of P. hardwickii would play an important part for further studies on molecular systematics and population genetics.