Comparative genomic analysis of hyper-ammonia producing Acetoanaerobium sticklandii DSM 519 with purinolytic Gottschalkia acidurici 9a and pathogenic Peptoclostridium difficile 630

Acetoanaerobium sticklandii DSM519 (CST) is a hype-ammonia producing non-pathogenic anaerobe that can use amino acids as important carbon and energy sources through the Stickland reactions. Biochemical aspects of this organism have been extensively studied, but systematic studies addressing its metabolic discrepancy remain scant. In this perspective, we have intensively analyzed its genomic and metabolic characteristics to comprehend the evolutionary conservation of amino acid catabolism by a comparative genomic approach. The whole-genome data indicated that CST has shown a phylogenomic similarity with hyper-ammonia producing, purinolytic, and proteolytic pathogenic Clostridia. CST has shown to common genomic context sharing across the purinolytic Gottschalkia acidurici 9a and pathogenic Peptoclostridium difficile 630. Genome syntenic analysis described that syntenic orthologs might be originated from the recent ancestor at a slow evolution rate and syntenic-out paralogs evolved from either CDF or CAC via alpha-event and beta-event. Collinearity of either gene orders or gene families was adjusted with syntenic out-paralogs across these genomes. The genome-wide metabolic analysis predicted 11 unique putative metabolic subsystems from the CST genome for amino acid catabolism and hydrogen production. The in silico analysis of our study revealed that a characteristic system for amino acid catabolism-directed biofuel synthesis might have slowly evolved and established as a core genomic content of CST.

Automated summary

Acetoanaerobium sticklandii DSM519 is a non-pathogenic anaerobe capable of producing high levels of ammonia using amino acids as carbon and energy sources. Comparative genomic analysis reveals that CST shares genomic context with other hyper-ammonia producing, purinolytic, and proteolytic bacteria, suggesting a slow evolution rate and common ancestry for certain genetic elements. Genomic and metabolic analysis predicts unique metabolic subsystems for amino acid catabolism and hydrogen production in CST.