Key Enzymes Enabling the Growth of Arthrobacter sp. Strain JBH1 with Nitroglycerin as the Sole Source of Carbon and Nitrogen

Abstract

<jats:title>ABSTRACT</jats:title><jats:p>Flavoprotein reductases that catalyze the transformation of nitroglycerin (NG) to dinitro- or mononitroglycerols enable bacteria containing such enzymes to use NG as the nitrogen source. The inability to use the resulting mononitroglycerols limits most strains to incomplete denitration of NG. Recently,<jats:named-content content-type="genus-species">Arthrobacter</jats:named-content>strain JBH1 was isolated for the ability to grow on NG as the sole source of carbon and nitrogen, but the enzymes and mechanisms involved were not established. Here, the enzymes that enable the<jats:named-content content-type="genus-species">Arthrobacter</jats:named-content>strain to incorporate NG into a productive pathway were identified. Enzyme assays indicated that the transformation of nitroglycerin to mononitroglycerol is NADPH dependent and that the subsequent transformation of mononitroglycerol is ATP dependent. Cloning and heterologous expression revealed that a flavoprotein catalyzes selective denitration of NG to 1-mononitroglycerol (1-MNG) and that 1-MNG is transformed to 1-nitro-3-phosphoglycerol by a glycerol kinase homolog. Phosphorylation of the nitroester intermediate enables the subsequent denitration of 1-MNG in a productive pathway that supports the growth of the isolate and mineralization of NG.</jats:p>

Old Yellow Enzyme-Catalysed Asymmetric Hydrogenation: Linking Family Roots with Improved Catalysis

“…Nevertheless, the enzymes AtOPR1-AtOPR3 from Arabidopsis thaliana [65,66], and LeOPR1-LeOPR3 from Solanum lycopersicum (tomato) [67,68], were characterised according to their structure, function and physiological role. Two thirds of the characterised OYEs have been obtained from various classes of bacteria including proteobacteria (28%) [69,70], actinobacteria (5%) [22,71,72], bacteroidetes (5%) [73,74], firmicutes (10%) [75][76][77], deinococcus-thermus (3%) [78][79][80], and cyanobacteria (17%) [21,81].…”

Persistence of pentolite (PETN and TNT) in soil microcosms and microbial enrichment cultures

“…1). In comparison, nitroglycerin has only three nitrate ester substitutes, and there is evidence that a metabolic pathway, which enables bacteria to use it as the sole source of carbon and nitrogen, has only recently evolved (Husserl et al 2010;Husserl et al 2012). In general, higher branched and larger molecules are more persistent, and it is likely that PETN is more persistent than nitroglycerin.…”

Metabolic Diversity for Degradation, Detection, and Synthesis of Nitro Compounds and Toxins

“…We identified the flavoprotein that catalyzes the specific conversion of NG to 1MNG without accumulation of the dead end metabolite 2MNG. We sequenced the genome of strain JBH1 and used transposon mutagenesis to establish the identity of the key enzyme responsible for the further degradation of 1MNG (32). The enzyme is closely related to glycerol kinase and seems to phosphorylate MNG.…”

“…An enzyme related to old yellow enzyme (PfvC) catalyzes the initial denitration of nitroglycerin to 1-mononitroglycerol. Mononitroglycerol kinase (MngP) phorphorylates mononitroglycerol before release of the final nitro group(32).…”