Taxonomic Binning Approaches and Functional Characteristics of the Microbial Community during the Anaerobic Digestion of Hydrolyzed Corncob

Abstract

Maize forms the basis of Mexican food. As a result, approximately six million tons of corncob are produced each year, which represents an environmental issue, as well as a potential feedstock for biogas production. This research aimed to analyze the taxonomic and functional shift in the microbiome of the fermenters using a whole metagenome shotgun approach. Two strategies were used to understand the microbial community at the beginning and the end of anaerobic digestion: (i) phylogenetic analysis to infer the presence and coverage of clade-specific markers to assign taxonomy and (ii) the recovery of the individual genomes from the samples using the binning of the assembled scaffolds. The results showed that anaerobic digestion brought some noticeable changes and the main microbial community was composed of Corynebacterium variable, Desulfovibrio desulfuricans, Vibrio furnissii, Shewanella spp., Actinoplanes spp., Pseudoxanthomonas spp., Saccharomonospora azurea, Agromyces spp., Serinicoccus spp., Cellulomonas spp., Pseudonocardia spp., Rhodococcus rhodochrous, Sphingobacterium spp. Methanosarcina mazei, Methanoculleus hydrogenitrophicus, Methanosphaerula spp., Methanoregula spp., Methanosaeta spp. and Methanospirillum spp. This study provides evidence of the drastic change in the microbial community structure in a short time and the functional strategy that the most representative microorganisms of the consortia used to carry out the process.