• He Y, Mathieu J, Yang Y, Yu P, d Si, Alvarez PJ. (2017) 1,4-Dioxane Biodegradation by Mycobacterium dioxanotrophicus PH-06 Is Associated with a Group-6 Soluble Di-Iron Monooxygenase. Environ Sci Technol Lett 4(11), 494-499.

1,4-Dioxane (dioxane) is a groundwater contaminant of emerging concern for which bioremediation may be a promising strategy. Several bacterial strains can metabolize dioxane or degrade it cometabolically. However, the molecular basis of dioxane biodegradation is only partially understood, and the gene coding for dioxane/tetrahydrofuran (THF) monooxygenase in Pseudonocardia dioxanivorans CB1190 is the only well-characterized catabolic gene. Here, we identify a novel group-6 propane monooxygenase gene cluster (prmABCD) in Mycobacterium dioxanotrophicus PH-06, which is a bacterium with superior dioxane degradation kinetics compared with CB1190. Whole genome sequencing of PH-06 revealed the existence of a single soluble di-iron monooxygenase (SDIMO). RNA sequencing and reverse transcription quantitative PCR (RT-qPCR) subsequently confirmed that all four components of this gene cluster are upregulated when PH-06 is grown on dioxane compared with growth on acetate or glucose as negative controls. This first characterization of a group-6 SDIMO associated with dioxane biodegradation suggests that dioxane-degrading genes may be more diverse than previously appreciated. A primer/probe set designed to target the large hydroxylase subunit of this gene cluster exhibited high selectivity (no false positives) and high sensitivity (detection limit = 3000–4000 gene copies/mL culture), which may be useful to help assess the presence of dioxane degraders at contaminated sites and minimize false negatives.

(Read the full article…)

De novo transcriptome analysis of Ammopiptanthus nanus and its comparative analysis with A. mongolicus Insights into the MicroRNA-regulated response of bermudagrass to cold and salt stress