Characterization of the Bacterial Microbiome Structure and Identification of the Beneficial Genera in the Leaf Litter Compost for its Potential Application as a Bioorganic Fertilizer

Abstract

This study investigates the potential of leaf and various organic waste composts as bio-organic fertilizers using 16S rRNA metagenomics. The microbial richness and diversity analysis, employing alpha and beta diversity indices, reveal substantial variations influenced by organic substrates during composting. The leaf compost had a high total OTU (70,554) but low microbial diversity (Chao 1 index = 272.27). The kitchen waste compost had the highest microbial diversity (Chao 1 index = 429.18). Positive correlations between microbial biomass, diversity, and compost quality highlighted the pivotal role of microbial activity. The beneficial genera identified across all the bio-composts were Lactobacillus, Leuconostoc, Sphingobacterium, Paenibacillus, Pseudomonas, and Clostridium. Some pathogenic genera were also detected in all the composts analyzed, viz. Prevotella, Agrobacterium, Fusobacterium, and Streptococcus. Nonetheless, the ratio of beneficial to the pathogenic genera was generally high in all compost, highlighting the enrichment with beneficial microorganisms. The leaf compost demonstrated the highest proportion of beneficial genera, about 92%, indicating significant bio-fertilizing potential, with a low % level of pathogenic genera of about 3%. Thus, the leaf compost has excellent potential to be used as a bio-organic fertilizer. Understanding the microbial composition of organic waste composts is crucial for its application as bio-fertilizer for promoting sustainable agriculture.