Improving Arsenic Tolerance of Pyrococcus furiosus by the Heterologous Expression of a Respiratory Arsenate Reductase.

Improving Arsenic Tolerance of Pyrococcus furiosus by the Heterologous Expression of a Respiratory Arsenate Reductase. Appl Environ Microbiol. 2020 Aug 28;: Authors: Haja DK, Wu CH, Ponomarenko O, Poole FL, George GN, Adams MWW Abstract Arsenate is a notorious toxicant that is known to disrupt multiple biochemical pathways. Many microorganisms have developed mechanisms to detoxify arsenate using the ArsC-type arsenate reductase and some even use arsenate as a terminal electron acceptor for respiration involving the arsenate respiratory reductase (Arr). ArsC-type reductases have been studied extensively but the phylogenetically-unrelated Arr system is less investigated and has not been characterized from Archaea. Herein, we heterologously-expressed the genes encoding Arr from the crenarchaeon Pyrobaculum aerophilum in the euryarchaeon Pyrococcus furiosus, both of which grow optimally near 100°C. Recombinant P. furiosus was grown on molybdenum (Mo)- or tungsten (W)-containing media and two types of recombinant Arr enzymes were purified, one containing Mo (Arr-Mo) and one containing W (Arr-W). Purified Arr-Mo had a 140-fold higher specific activity in arsenate (AsV) reduction than Arr-W and Arr-Mo also reduced arsenite (AsIII). The P. furiosus strain expressing Arr-Mo (the Arr strain) was able to use arsenate as a terminal electron acceptor during growth on peptides. In addition, the Arr strain had increased tolerance compared to the p...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research