The nitrated compounds 2,4-dinitrotoluene (2,4-DNT), 2,4,6-trinitrotoluene (TNT), and pentaerythritol tetranitrate (PETN) are toxic xenobiotics widely used in various industries. They often coexist as environmental contaminants. The aims of this study were to evaluate the transformation of 100 mg L-1 of TNT, 2,4-DNT, and PETN by Raoultella planticola M30b and Rhizobium radiobacter M109c and identify enzymes that may participate in the transformation. These strains were selected from 34 TNT transforming bacteria. Cupriavidus metallidurans DNT was used as a reference strain for comparison purposes. Strains DNT, M30b and M109c transformed 2,4-DNT (100%), TNT (100, 94.7 and 63.6%, respectively), and PETN (72.7, 69.3 and 90.7%, respectively). However, the presence of TNT negatively affects 2,4-DNT and PETN transformation (inhibition > 40%) in strains DNT and M109c and fully inhibited (100% inhibition) 2,4-DNT transformation in R. planticola M30b.Genomes of R. planticola M30b and R. radiobacter M109c were sequenced to identify genes related with 2,4-DNT, TNT or PETN transformation. None of the tested strains presented DNT oxygenase, which has been previously reported in the transformation of 2,4-DNT. Thus, unidentified novel enzymes in these strains are involved in 2,4-DNT transformation. Genes encoding enzymes homologous to the previously reported TNT and PETN-transforming enzymes were identified in both genomes. R. planticola M30b have homologous genes of PETN reductase and xenobiotic reductase B, while R. radiobacter M109c have homologous genes to GTN reductase and PnrA nitroreductase. The ability of these strains to transform explosive mixtures has a potentially biotechnological application in the bioremediation of contaminated environments.

中文翻译：

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Raoultella planticola M30b和Rhizobium radiobacter M109对TNT、2,4-DNT和PETN的转化及相关酶的探索

硝化化合物 2,4-二硝基甲苯 (2,4-DNT)、2,4,6-三硝基甲苯 (TNT) 和季戊四醇四硝酸酯 (PETN) 是广泛用于各个行业的有毒异生素。它们通常作为环境污染物共存。本研究的目的是评估 Raoultella planticola M30b 和 Rhizobium radiobacter M109c 对 100 mg L-1 TNT、2,4-DNT 和 PETN 的转化，并确定可能参与转化的酶。这些菌株选自 34 种 TNT 转化细菌。Cupriavidus metallidurans DNT用作比较目的的参考菌株。菌株 DNT、M30b 和 M109c 转化了 2,4-DNT（100%）、TNT（分别为 100、94.7 和 63.6%）和 PETN（分别为 72.7、69.3 和 90.7%）。然而，TNT 的存在会对 2,4-DNT 和 PETN 转化产生负面影响（抑制 > 40%) 在菌株 DNT 和 M109c 中并完全抑制 (100% 抑制) R. planticola M30b 中的 2,4-DNT 转化。对 R. planticola M30b 和 R. radiobacter M109c 的基因组进行测序以鉴定与 2,4-DNT 相关的基因DNT、TNT 或 PETN 转换。所测试的菌株均不存在 DNT 加氧酶，这在先前在 2,4-DNT 的转化中已有报道。因此，这些菌株中未鉴定的新型酶参与了 2,4-DNT 转化。在两个基因组中都鉴定出编码与先前报道的 TNT 和 PETN 转化酶同源的酶的基因。R. planticola M30b 具有 PE​​TN 还原酶和异生物质还原酶 B 的同源基因，而 R. radiobacter M109c 具有与 GTN 还原酶和 PnrA 硝基还原酶同源的基​​因。