The capability of plant-bacterial consortia to reduce the genotoxicity of unsymmetrical dimethylhydrazine

Despite its proven high toxicity, unsymmetrical dimethylhydrazine (UDMH) continues to be used in rocket technology and some other areas of human activity. In this work, the ability of plant-bacterial consortia to reduce the genotoxicity of UDMH and its incomplete oxidation products was investigated. Genotoxicity was assessed using a specific lux-biosensor, <i>Escherichia coli</i> MG1655 pAlkA-lux, which emits stronger light when cellular DNA is alkylated. For microbiological biodegradation, the <i>Bacillus subtilis</i> KK1112 strain was isolated from the soil <i>via</i> a two-stage selection process for resistance to high UDMH concentrations exceeding 5000 MAC. This strain’s ability to biodegrade UDMH was demonstrated, as treatment of UDMH-polluted medium with KK1112 resulted in reduced DNA alkylation. A synergistic reduction in the DNA-alkylating potency of UDMH oxidation products was studied under the combined application of bacteria KK1112 and plant seedlings: <i>Bromus inermis</i> Leyss, <i>Medicago varia</i> Mart. and <i>Phleum pratense</i> L. The greatest effect was achieved when bacteria were used in combination with <i>B. inermis</i>. KK1112 cells accelerated seedling development and mitigated UDMH-induced growth inhibition. The findings suggest that the consortium of KK1112 and <i>B. inermis</i> has a great potential for remediation of UDMH-polluted soils in arid climatic zones.