Inhibition of biological TCE and sulphate reduction in the presence of iron nanoparticles.

Iron (Fe) nanoparticles are increasingly being employed for the remediation of Chlorinated Aliphatic Hydrocarbon (CAH) contaminated sites. However, these particles have recently been reported to be cytotoxic to bacterial cells, and may therefore have a negative impact on exposed microbial communities. The overall objective of this study was to investigate the impact of Fe nanoparticles on the biodegradation of CAHs by an indigenous dechlorinating bacterial community.

Optimization of nano-scale nickel/iron particles for the reduction of high concentration chlorinated aliphatic hydrocarbon solutions.

The use of nano-scale particles as a means of environmental remediation still provides a comparatively novel approach for the treatment of contaminated waters. The current study compares the reactivity of micro-scale Fe, nano-scale Fe and nano-scale Ni/Fe (nickel/iron) particles specifically for dechlorination of solutions containing 350 mg L(-1) of TCE (concentration measured at a contaminated site in Derbyshire, UK). The results indicated that employing 1 g L(-1) of reactive material for dechlorination in the monometallic form (both micro- and nano-scale) exhibited very little reduction capability compared with the bimetallic Ni/Fe nano-scale particles, containing 28.

Evolution of compatible replicons of the related IncQ-like plasmids, pTC-F14 and pTF-FC2.

Two closely related but compatible plasmids of the IncQ-2alpha and IncQ-2beta groups, pTF-FC2 and pTC-F14, were discovered in two acidiphilic chemolithotrophic bacteria. Cross-complementation and cross-regulation experiments by the replication proteins were carried out to discover what changes were necessary when the plasmids evolved to produce two incompatibility groups. The requirement of a pTC-F14 oriV for a RepC DNA-binding protein was plasmid specific, whereas the requirement for the RepA helicase and RepB primase was less specific and could be complemented by the IncQ-2alpha plasmid pTC-FC2, and the IncQ-1beta plasmid pIE1108.