Isolation and characterization of an efficient nitro-reducing bacterium, Streptomyces mirabils DUT001, from soil

A bacterial strain, designated as DUT001, was isolated from soil samples collected in Qingpu, Shanghai, China, and found to be capable of reducing nitro polycyclic aromatic compounds and polynitrated aromatic compounds. It was identified as Streptomyces mirabils based on morphological and physiological-biochemical properties, as well as 16S rDNA sequences and phylogenetic analysis. The optimum growth temperature and pH for Streptomyces mirabils DUT001 are 28A degrees C and 7.2, respectively. The best carbon source and nitrogen source are glucose and yeast extract. Streptomyces mirabils DUT001 exhibited highly efficient activity in reduction of nitroaromatic compounds, 4-nitro-1, 8-naphthalic anhydride (4-NNA), 3-nitro-1, 8-naphthalic anhydride, 4-nitrophthalimide, 3-nitrophthalimide 1, 3-dinitrobenzene, and 1, 4-dinitrobenzene, to their amino derivatives with yields ranging from 70-99% under mild conditions. 1% (w/v) of the nonionic surfactant, Triton X-100 and 0.1 mM of redox mediator, anthraquinone-2, 6-disulfonate (AQDS), could accelerate the nitroreduction process. The bioreduction activity of the Streptomyces mirabils DUT001 offers its application potentials in bioremediation of nitroaromatic compounds and synthesis of important amino derivatives.