Short Genome CommunicationsComplete genome sequence of the thermophilic bacterium Geobacillus subterraneus KCTC 3922T as a potential denitrifier

- The complete genome sequences of Geobacillus subterraneus type strain (KCTC 3922T) and G. thermodenitrificans type strain (KCTC 3902T).
- G. subterraneus KCTC 3922T contains the complete gene clusters involved in denitrification among the genus Geobacillus.
- G. thermodenitrificans KCTC 3902T lacks the reduction activity of nitrate due to the absence of molybdopterin molybdenumtransferase.
- The G. subterraneus KCTC 3922T genome highlights an industrial impact for nitrate-contaminated sewage and wastewater treatment.

Denitrification is a crucial process for the global nitrogen cycle through the reduction of nitrates by heterotrophic bacteria. Denitrifying microorganisms play an important role in eliminating fixed nitrogen pollutants from the ecosystem, concomitant with N2O emission. Although many microbial denitrifiers have been identified, little is known about the denitrifying ability of the genus Geobacillus. Here, we report the first complete genome sequences of Geobacillus subterraneus KCTC 3922T, isolated from Liaohe oil field in China, and G. thermodenitrificans KCTC 3902T. The strain KCTC 3922T contains a complete set of genes involved in denitrification, cofactor biogenesis, and transport systems, which is consistent with a denitrifying activity. On the other hand, G. thermodenitrificans KCTC 3902T exhibited no denitrifying activity probably due to the lack of molybdnumtransferase (moeA) and nitrite transporter (nirC) genes. Therefore, comparative genome analysis of Geobacillus strains highlights the potential impact on treatment of nitrate-contaminated environments.