Key genomes, transcriptomes, proteins, and metabolic factors involved in the detoxification/tolerance of TNT and its intermediates by bacteria in anaerobic/aerobic environments

Abstract

Novel microbial strains capable of efficient degradation of TNT and typical intermediates (2-ADNT and 4-ADNT) in aerobic/anaerobic environment were screened and isolated from ammunition-contaminated sites. The key genomes, transcriptomes, proteins, and metabolic factors for microbial detoxification/tolerance to pollutants in anaerobic and aerobic environments were analyzed for the first time. The bacterial genome, which is rich in metabolism and environmental information-processing functional genes, provides transcriptional and translational-related proteins for detoxifying/tolerating pollutants. At the transcriptional level, bacteria significantly expressed genes related to inositol phosphate metabolism for regulating membrane transport, maintaining the cytoskeleton, and signal transduction. At the protein level, genes involved in antioxidation, fat metabolism, sugar synthesis/degradation, and pyruvate metabolism were significantly expressed. At the metabolic level, riboflavin metabolism, which regulates membrane integrity, protects against oxidative stress, and maintains the sugar–protein–fat balance, showed significant responses. Bacteria simultaneously regulate amino acid metabolism, carbohydrate metabolism, and N/P/S cycles to maintain homeostatic cellular energy supplies. The key pathway for pollutant degradation in bacteria is nitrotoluene degradation. The molecular mechanism of bacterial tolerance to pollutants involves the regulation of oxidative phosphorylation and basic cycle pathways to maintain gene transcription, protein translation, and metabolic cycles.