Composition, Structure, and Functional Shifts of Prokaryotic Communities in Response To Co‑Composting of Various Nitrogenous Green Feedstocks

Abstract

Background Thermophilic composting is a promising method of sanitizing pathogens in manure and a source of agriculturally important thermostable enzymes and microorganisms from organic wastes. Despite the extensive studies on compost prokaryotes, shifts in microbial profles under the infuence of various green materials and composting days are still not well understood, considering the complexity of the green material sources. Here, the efect of regimens of green composting material on the diversity, abundance, and metabolic capacity of prokaryotic communities in a thermophilic compost environment was examined. Methods Total community 16S rRNA was recovered from triplicate compost samples of Lantana-based, Tithoniabased, Grass-based, and mixed (Lantana + Tithonia + Grass)- based at 21, 42, 63, and 84days of composting. The 16S rRNA was sequenced using the Illumina Miseq platform. Bioinformatics analysis was done using Divisive Amplicon Denoising Algorithm version 2 (DADA2) R version 4.1 and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States version 2 (PICRUSt2) pipelines for community structure and metabolic profles, respectively. In DADA2, prokaryotic classifcation was done using the Refseq-ribosomal database project (RDP) and SILVA version 138 databases. Results Our results showed apparent diferences in prokaryotic community structure for total diversity and abundance within the four compost regimens and composting days. The study showed that the most prevalent phyla during composting included Acidobacteriota, Actinobacteriota, Bacteroidota, Chlorofexi, and Proteobacteria. Additionally, there were diferences in the overall diversity of metabolic pathways but no signifcant diferences among the various compost treatments on major metabolic pathways like carbohydrate biosynthesis, carbohydrate degradation, and nitrogen biosynthesis. Conclusion Various sources of green material afect the succession of compost nutrients and prokaryotic communities. The similarity of amounts of nutrients, such as total Nitrogen, at the end of the composting process, despite differences in feedstock material, indicates a signifcant infuence of composting days on the stability of nutrients during composting