Isolation and Molecular Characterization of Hydrocarbon Degrading Nocardia Isolated from Hospital Environments in Isfahan Province

Biodegradation is the metabolic ability of some microorganisms in degrading or transforming the organic and inorganic contaminants into less harmful and non-hazardous substances, which are then integrated into the natural biogeochemical cycles. Some microorganisms, mainly the members of family Actinomycetes, were found with the capability of transforming and degrading the polluting agents. In this study, three different Nocardia species with the ability to biodegrade organic and inorganic compounds were isolated from soil in Isfahan province. The soil samples were collected from the hospital environments. Isolation process was done according to the standard methods. The identification and characterization of the isolates were based on the conventional and molecular methods, including direct sequence analysis of almost full length of 16S rRNA gene. Almost, the complete 16S rRNA gene sequences of the strains under study revealed that the isolates coded as NR6, NR17, NR18, NR25, NR26, and NR28 were the strains of N. cyriacigeorgica; NR7, NR34, and NR50 were the strains of N. coubleae; and NR4 was the strain of N. otitidiscaviarum. The relationship between the isolates under study and standard strain of Nocardia was supported by a phylogenetic tree of 16S rRNA gene. In this study, 10 Nocardia strains with the capability of biotransforming polluting agents were isolated from the hospital environments. It was the first study conducted on the isolation and characterization of Nocardia strains, with the capability of degrading polluting agents, from Iranian hospitals. This study can be considered as a pioneer to develop a new insight about the study of microbial diversity in Iran using an applied approach to deal with environmental challenges.