Research in anoxic environments is a relatively new and rapidly growing branch
of science that is of general interest to many students of diverse microbial communities.
The term anoxia means absence of atmospheric oxygen, while the term
hypoxia refers to O 2 depletion or to an extreme form of “low oxygen.” Both terms
anoxia and hypoxia are used in various contexts.
It is accepted that the initial microorganisms evolved anaerobically and
thrived in an atmosphere without oxygen. The rise of atmospheric oxygen
Sulfatases form a major group of enzymes present in prokaryotes and
eukaryotes. This class of hydrolases is unique in requiring essential post-translational modification of a critical active-site cysteinyl or seryl residue
to Ca-formylglycine (FGly).
It has long been accepted that bacterial quinol-fumarate
reductase (QFR)generally uses a low-redox-potential
naphthoquinone, menaquinone (MK), as the electron
donor, whereas mitochondrial QFR from facultative and
anaerobic eukaryotes uses a low-redox-potential benzoqui-none, rhodoquinone (RQ), as the substrate. In the present
study, we purifiednovel complex II fromtheRQ-containing
phototrophic purple bacterium,Rhodoferax fermentansthat
exhibited high rhodoquinol-fumarate reductase activity in
addition to succinate-ubiquinone reductase activity....