In our previous study on the ultrastructure of M. oxyfera, neither TEM nor electron tomography showed the presence of ICM in M. oxyfera cells under the current growth conditions (Wu et al., 2012). This observation raised the question regarding the actual ABT-199 cost intracellular location of the pMMO enzyme in M. oxyfera. Here, we show that, consistent with the previous observation, M. oxyfera does not develop ICM under the current growth conditions. Ultrathin section of M. oxyfera cells incubated with α-pMmoB showed gold particles both at and close to
the cytoplasmic membrane (Figs 4 and 5). These results together with the presence of membrane spanning regions in the pMmoB sequence (Fig. 1b) indicate that the pMMO enzyme is most likely located at the cytoplasmic
membrane of M. oxyfera cells. In conclusion, our results suggest that pMMO and NirS enzymes are located in the cytoplasmic membrane and the periplasm of M. oxyfera cells, respectively. Double-labelling experiments showed the co-occurrence of both pMMO and NirS in single M. oxyfera cells. Our results validate the presence of key enzymes in methane- and nitrite-converting pathways in the M. oxyfera metagenome assembly. We would like to thank Katinka van de Pas-Schoonen for support in maintaining the M. oxyfera enrichment culture, Harry R. Harhangi, Huub Op den Camp and Jan T. Keltjens for stimulating discussions, Sarah Neumann for support in the production of the antisera and Geert-Jan Janssen for support at the general instruments facility. L.v.N. Dorsomorphin clinical trial is supported by the Netherlands Organization for Scientific Research (VENI grant 863.09.009), M.L.W. by a Horizon grant (050-71-058), M.S. by ERC 242635 and M.S.M.J. by ERC 232937. “
“Streptococcus pneumoniae, the leading etiological agent of pneumonia, shares a high degree of DNA Phosphatidylinositol diacylglycerol-lyase sequence homology with the viridans group of streptococci. The clinical and pathological manifestations may
present with different features, and discrimination between S. pneumoniae and its close viridans cocci relatives, such as Streptococcus mitis and Streptococcus oralis, is still quite difficult. The 445-bp sequences of the N-terminal region of rpoA from nine S. pneumoniae, seven S. mitis, ten S. oralis, and two related strains were determined and compared with their respective 16S rRNA gene sequences to establish their usefulness in phylogenetic analysis. Pairwise comparisons of rpoA sequences among the species showed higher rates of evolution with lower similarities (92.3–100%) than those of 16S rRNA genes (96.8–100%). The rpoA-based phylogeny generated deeper branches and presented improved discriminatory resolution than the 16S rRNA gene-based phylogeny.