Summary Vermicomposting using black soldier fly ( BSF ) larvae ( Hermetia illucens ) has gradually become a promising biotechnology for waste management, but knowledge about the larvae gut microbiome is sparse. In this study, 16S rRNA sequencing, SourceTracker, and network analysis were leveraged to decipher the influence of larvae gut microbiome on food waste ( FW ) biodegradation. The microbial community structure of BSF vermicompost ( BC ) changed greatly after larvae inoculation, with a peak colonization traceable to gut bacteria of 66.0%. The relative abundance of 11 out of 21 metabolic function groups in BC were significantly higher than that in natural composting ( NC ), such as carbohydrate‐active enzymes. In addition, 36.5% of the functional genes in BC were significantly higher than those in NC . The changes of metabolic functions and functional genes were significantly correlated with the microbial succession. Moreover, the bacteria that proliferated in vermicompost, including Corynebacterium , Vagococcus , and Providencia , had strong metabolic abilities. Systematic and complex interactions between the BSF gut and BC bacteria occurred over time through invasion, altered the microbial community structure, and thus evolved into a new intermediate niche favourable for FW biodegradation. The study highlights BSF gut microbiome as an engine for FW bioconversion, which is conducive to bioproducts regeneration from wastes.

No abstract

Rice fields provide food for over half of the world’s human population. The ecology of paddy soil microbiomes is shaped by human activities, which can have a profound impact on rice yield, greenhouse gas emissions, and soil health.

Abstract Background: Rice paddy soil-associated microbiota participate in biogeochemical processes that underpin rice yield and soil sustainability, yet continental-scale biogeographic patterns of paddy soil microbiota remain elusive. Here, the soil bacteria of four typical Chinese rice-growing regions were characterized over large-scale space and compared with adjacent non-paddy soils.Results: The geographic patterns of paddy soil bacteria were significantly different from non-paddy soils, with lower alpha diversity, unique taxonomic and functional composition, and distinct co-occurrence network topology. Both stochastic and deterministic processes shaped soil bacteria assembly, but paddy exhibited a stronger deterministic signature than non-paddy samples, especially due to the roles of climate determinants. The continental biogeographic variance in bacterial community structure was driven by the competition between two mutually-exclusive bacterial modules in the co-occurrence network, and suggested antagonistic species-to-species interactions as potential selective forces may greatly shape their community structures. Keystone taxa identified in network models, such as Actinobacteria, Chloroflexi, and Proteobacteria, were demonstrated to be preferentially affected by environmental factors than other community members and showed high sensitivity to environmental changes, whereby the environmental factors greatly shaped the paddy soil bacterial communities by leveraging changes in keystones.Conclusions: The strong interplay between biotic/abiotic factors may greatly construct paddy soil microbial community and their uniqueness as compared with non-paddy soils. Microbial biogeographical analyses with novel insights into underlying determinants investigated on intensively-cultivated paddy field soils may aid in elucidating microbial changes subjected to land-use changes following the transformation between natural and agro-ecosystem, and also facilitate microbial community manipulation for better crop productivity and soil sustainability worldwide.