D-amino acid catabolism is common among soil-dwelling bacteria

Soil and rhizosphere environments were examined in order to determine the identity and relative abundance of bacteria that catabolize d-and l-amino acids as the sole source of carbon and nitrogen. All substrates were readily catabolized by bacteria from both environments, with most d-amino acids giving similar CFU counts to their l-amino acid counterparts. CFU count ratios between l-and d-amino acids typically ranged between 2 and 1. Isolates were phylogenetically typed in order to determine the identity of d-amino acid catabolizers. Actinobacteria, specifically the Arthrobacter genus, were abundant along with members of the α-and β-Proteobacteria classes.