Halogenated organic compounds are naturally occurring in subsurface environments; however, accumulation of the degradative intermediate cis-1,2-dichloroethene (cDCE) at soil and groundwater sites contaminated with xenobiotic chlorinated ethenes is a global environmental and public health issue. Identifying microorganisms capable of cDCE degradation in these environments is of interest because of their potential application to bioremediation techniques. In this study, we sequenced, assembled, and analyzed the complete genome of Acinetobacter pittii CEP14, a strain isolated from chloroethene-contaminated groundwater, that has demonstrated the ability for aerobic cometabolic degradation of cDCE in the presence of n-hexane, phenol, and toluene. The A. pittii CEP14 genome consists of a 3.93 Mbp-long chromosome (GenBank accession no. CP084921) with a GC content of 38.9% and three plasmids (GenBank accession no. CP084922, CP084923, and CP084924). Gene function was assigned to 83.4% of the 3,930 coding DNA sequences. Functional annotation of the genome revealed that the CEP14 strain possessed all genetic elements to mediate the degradation of a range of aliphatic and aromatic compounds, including n-hexane and phenol. In addition, it harbors gene clusters involved in cytosol detoxification and oxidative stress resistance, which could play a role in the mitigation of toxic chemical intermediates that can arise during the degradation of cDCE. Gene clusters for heavy metal and antibiotic resistance were also identified in the genome of CEP14. These results suggest that CEP14 may be a versatile degrader of xenobiotic compounds and well-adapted to polluted environments, where a combination of heavy metal and organic compound pollution is often found.

• Keywords
• Acinetobacter pittii, Chlorinated ethenes (CEs), Cometabolism, Oxygenase, Phenol, Whole-genome shotgun sequencing, cis-1,2-dichloroethene (cDCE) biodegradation,
• MeSH
• Acinetobacter MeSH
• Biodegradation, Environmental MeSH
• Dichloroethylenes MeSH
• Phenols * MeSH
• Genomics MeSH
• Xenobiotics * MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• 1,2-dichloroethylene MeSH Browser
• Dichloroethylenes MeSH
• Phenols * MeSH
• Xenobiotics * MeSH

The application of zero-valent iron particles (ZVI) for the treatment of heavily polluted environment and its biological effects have been studied for at least two decades. Still, information on the impact on bacterial metabolic pathways is lacking. This study describes the effect of microscale and nanoscale ZVI (mZVI and nZVI) on the abundance of different metabolic pathways in freshwater bacterial communities. The metabolic pathways were inferred from metabolism modelling based on 16S rRNA gene sequence data using paprica pipeline. The nZVI changed the abundance of numerous metabolic pathways compared to a less influencing mZVI. We identified the 50 most affected pathways, where 31 were related to degradation, 17 to biosynthesis, and 2 to detoxification. The linkage between pathways was two times higher in nZVI samples compared to mZVI, and was specifically higher considering the arsenate detoxification II pathway. Limnohabitans and Roseiflexus were linked to the same pathways in both nZVI and mZVI. The prediction of metabolic pathways increases our knowledge of the impacts of nZVI and mZVI on freshwater bacterioplankton.

• MeSH
• Water Pollutants, Chemical * MeSH
• Chloroflexi * MeSH
• Genes, rRNA MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Fresh Water MeSH
• Iron MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Water Pollutants, Chemical * MeSH
• RNA, Ribosomal, 16S MeSH
• Iron MeSH