Sulfide-Oxidizing Nitrate Reducer Can Cause Severe Corrosion during Oil Production
Microbiologically influenced corrosion of metal infrastructures is a common problem in the oil and gas industry. Using a model oil field bacterium, Lahme et al. (e01891-18) showed how its sulfide-oxidizing and nitrate-reducing activity can affect corrosion of steel infrastructures. Sulfide-oxidizing bacteria are often enriched during oil production when nitrate is applied to “sour” (i.e., sulfidic) production waters before they are reinjected into reservoirs. The study identified the key factors responsible for severe corrosion by those bacteria, which will help to identify potential corrosion risks during oil production.
Potential Role of Vibrio mimicus in the Evolution of Vibrio cholerae Hybrid Strains
Unraveling the evolution of Vibrio cholerae hybrid strains, which are emerging as the predominant cause of cholera, is a prime issue to understand their pathogenetic diversification inflicting disease severity. Neogi et al. (e01977-18) discovered that like V. cholerae hybrid strains, particular clonally related Vibrio mimicus strains harbor novel variants of cholera toxin (CT), the toxin-coregulated pilus, and the regulatory protein ToxT. Their observed integration of a hybrid-type CTX phage carrying the variant ctx genes, tandemly arrayed with multiple copies of pre-CTX and satellite RS1, in V. mimicus unveils an atypical evolutionary mechanism. This study highlights V. mimicus as a potential contributor to the evolution of V. cholerae hybrid strains.
Bacteria to the Rescue of Cultural Heritage
Protection of cultural heritage is of significance because of the inherent social and economic value of history. Iron is one of the most represented materials in cultural heritage. However, due to corrosion, the stability of iron artifacts is jeopardized. Kooli et al. (e02042-18) used two iron-reducing Aeromonas species for the development of an environmentally respectful approach based on the bio-induced formation of stable ferrous iron minerals at the surface of the objects. This paves the way for the application of a similar rationale for the design and development of novel biotechnological approaches for the protection of materials in heritage and other related fields.
Diverse Adaptations to Low CO2 Concentrations in Sulfur-Oxidizing Members of Gammaproteobacteria
Members of Hydrogenovibrio, Thiomicrorhabdus, and Thiomicrospira fix CO2 and oxidize reduced sulfur compounds at hydrothermal vents, coastal sediments, hypersaline lakes, and many other habitats. Scott et al. (e02096-18) show that they have diverse mechanisms for coping with low-CO2 conditions; they carry four types of evolutionarily independent inorganic carbon transporters, two of which are novel. All four transporters are widely distributed among Bacteria, providing insight into inorganic carbon uptake by autotrophs and heterotrophs. These transporters are active when mobilized into Escherichia coli, making them attractive candidates for efforts to engineer autotrophic organisms to catalyze carbon-neutral biochemistries of industrial importance.
Engineering a Novel Mercuric Reductase with Enhanced Thermal Stability
Mercury is the sixth-most-toxic element in the universe; however, it contaminates natural and human-built environments by different means. A “holy grail” for mercury detoxification is to find a bioremediation tool that can detoxify mercury, notably under extreme conditions. One such environment is the Red Sea brine pool, which is known for unusually high mercuric activity. Maged and colleagues (e02387-18) used molecular tools to design a thermostable enzyme that can work under these extreme conditions. Mutagenesis and molecular modeling highlight how some critical parts of the enzyme underlie its remarkable novelty.
- Copyright © 2019 American Society for Microbiology.
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- Sulfide-Oxidizing Nitrate Reducer Can Cause Severe Corrosion during Oil Production
- Potential Role of Vibrio mimicus in the Evolution of Vibrio cholerae Hybrid Strains
- Bacteria to the Rescue of Cultural Heritage
- Diverse Adaptations to Low CO2 Concentrations in Sulfur-Oxidizing Members of Gammaproteobacteria
- Engineering a Novel Mercuric Reductase with Enhanced Thermal Stability
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