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

Abstract

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 28°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.

Informing Efforts to Develop Nitroreductase for Amine Production

“…This suggests that the rest of the molecule plays a role in correctly positioning the nitro-derived hydroxylamine group for reduction by the enzyme. Indeed, the 4-nitro-1,8-naphthalic anhydride 8 that combines a larger aromatic π system with electron withdrawing substituents underwent reduction to the amine consistent with literature reports [ 59 ]. Additionally, our findings document amine production from a member of the NfsB subgroup.…”

“…While trinitrotoluene (TNT) and some other nitroaromatics are documented to undergo reduction to the corresponding amines, many of the reports of the greatest conversion have employed intact bacteria or even consortia of multiple strains [ 29 , 58 , 59 ]. However, such systems provide limited control over the reaction outcome, and in several cases the enzyme responsible for amine formation has been shown to be other than a NR [ 60 , 61 , 62 , 63 ].…”

Synthesis of Pharmaceutically Relevant Arylamines Enabled by a Nitroreductase from Bacillus tequilensis

“…Based on literature data and a genome mining approach, four nitroreductase-like flavoenzymes were initially selected for this study (see Supporting Information for details). Three of these flavoenzymes are well-characterized NRs that have been reported to perform amine synthesis starting from nitro aromatic compounds, namely NfnB from Mycobacterium smegmatis, [16,22] SNR from Streptomyces mirabilis [26,31] and NfnB from Sphingopyxis sp. [32] Additionally, a putative NR from Bacillus tequilensis, named BtNR, was also selected (Figure S1).…”

Microbe-mediated bioremediation: Current research and future challenges

“…Second, nitration is an essential chemical reaction for the commercial synthesis and uses of numerous amino aromatic intermediates as a feedstock for the production of explosive, pesticides, herbicides, polymers, dyes, medicine, and other products. Various microbes such as Arthrobacter ureafaciens, Pseudomonas sp., Rhodococcus wratislaviensis, Shewanella oneidensis, and Streptomyces mirabilis have been reported for the degradation of nitro-aromatic compounds [94][95][96][97][98]. Another microbes such as Pseudomonas putida, P. putida, P. mendocina, Burkholderia cepacia, B. cepacia and Ralstonia pickettii [99], Arthrobacter sp., Enterobacter agglomerans, Escherichia coli, Pseudomonas cepacia, Pseudomonas sp., Rhizobium sp., Staphylococcus aureus, and Xanthomonas sp.…”