Dissing George (noisepark9)

Most of the microbial degradation in oil reservoirs is believed to take place at the oil-water transition zone (OWTZ). However, a recent study indicates microbial life enclosed in μl-sized water droplets dispersed in heavy oil of the Pitch Lake in Trinidad & Tobago. This life in oil suggests that microbial degradation of oil also takes place in water pockets in the oil-bearing rock of an oil leg independent of the OWTZ. However, it is unknown if microbial life in water droplets dispersed in oil is a generic property of oil reservoirs rather than an exotic exception. Hence, we took samples from three heavy oil seeps, the Pitch Lake (Trinidad & Tobago), the La Brea Tar Pits (CA, USA) and an oil seep on the McKittrick oil field (CA, USA). All three tested oil seeps contained dispersed water droplets. Larger droplets between 1-10 μl revealed high cell densities of up to 109 cells ml-1 Tests for adenosine triphosphate (ATP) content and LIVE/DEAD staining showed that these populations consist of active and viable m separate oil seeps that are located thousands of kilometers away from each other, we propose that water droplets populated with microorganisms might be a generic trait of biodegraded oil reservoirs. Furthermore, microbes in these water droplets can contribute to the degradation of the oil. Copyright © 2020 Pannekens et al.While only a subset of Vibrio cholerae are human diarrheal pathogens, all are aquatic organisms. In this environment, they often persist in close association with arthropods. In the intestinal lumen of the model arthropod Drosophila melanogaster, methionine and methionine sulfoxide decrease susceptibility to V. cholerae infection. In addition to its structural role in proteins, methionine participates in the methionine cycle, which carries out synthetic and regulatory methylation reactions. It is, therefore, essential for the growth of both animals and bacteria. Methionine is scarce in some environments, and the facile conversion of free methionine to methionine sulfoxide in oxidizing environments interferes with its utilization. To ensure an adequate supply of methionine, the genomes of most organisms encode multiple high affinity uptake pathways for methionine as well as multiple methionine sulfoxide reductases, which reduce free and protein-associated methionine sulfoxide to methionine. To explore the roleust be identified and mutagenized. Here we have mutagenized every high affinity methionine uptake system and methionine sulfoxide reductase encoded in the genome of the diarrheal pathogen V. cholerae We use this information to determine that high affinity methionine uptake systems are sufficient to acquire methionine in the intestine of the model arthropod Drosophila melanogaster but are not involved in virulence and that the intestinal concentration of methionine must be between 0.05 mM and 0.5 mM. Copyright © 2020 American Society for Microbiology.The purple nonsulfur phototrophic bacterium Rhodopseudomonas palustris strain CGA009 uses the three-carbon dicarboxylic acid malonate as a sole carbon source under phototrophic conditions. However, this bacterium grows extremely slowly on this compound and does not have operons for the two pathways for malonate degradation that have been described in other bacteria. Many bacteria grow on a spectrum of carbon sources, some of which are classified as "poor" growth substrates because they support slow growth rates. This trait is rarely addressed in the literature, but slow growth is potentially useful in biotechnological applications where it is imperative for bacteria to divert cellular resources to value-added products rather than to growth. This prompted us to explore the genetic and physiological basis for the slow growth of R. palustris with malonate as a carbon source. There are two unlinked genes annotated as encoding a malonyl-CoA synthetase (MatB) and a malonyl-CoA decarboxylase (MatA) in the genome of m of malonate, but some of these elem