ubiquinone and n-hexane

Two Gram-negative, rod-shaped, non-spore-forming bacterial strains were isolated from a hexane-treated, full-scale biofilter from an oil mill. The strains were cultivated with hexane as the sole carbon source. One strain, MN154.3(T), showed a fatty acid profile that contained 16 : 0, 18 : 1cis11 and 19 : 0 cyclo11-12 as major compounds, while the second strain, isolate MN28(T), contained 14 : 0 3-OH, 16 : 0 and 18 : 1cis11 as the predominant fatty acids. On the basis of almost-complete 16S rRNA gene sequences, both strains could be allocated to the Nevskia branch of the class Gammaproteobacteria. The sequence similarities for strains MN154.3(T) and MN28(T) with respect to the most closely related type strains of this branch were 90.5 and 94.1 %, respectively. The sequence similarity between strains MN154.3(T) and MN28(T) was 90.6 %. The DNA G+C content of strain MN154.3(T) was 62.8 mol% and that for strain MN28(T) was 64.9 mol%. Both strains possessed ubiquinone-8 as the major quinone. On the basis of the 16S rRNA gene sequences of these two new isolates and several phenotypic differences exhibited with respect to known species of the Nevskia branch, strains MN154.3(T) and MN28(T) represent two novel genera and species, for which the names Alkanibacter difficilis gen. nov., sp. nov. and Singularimonas variicoloris gen. nov., sp. nov. are proposed. The type strain of Alkanibacter difficilis gen. nov., sp. nov. is MN154.3(T) (=DSM 14804(T)=LMG 22842(T)) and that of Singularimonas variicoloris gen. nov., sp. nov. is MN28(T) (=DSM 15731(T)=LMG 22844(T)).

Topics: Bacterial Typing Techniques; Base Composition; DNA, Bacterial; Fatty Acids; Gammaproteobacteria; Genes, Bacterial; Genes, rRNA; Hexanes; Industrial Waste; Molecular Sequence Data; Phenotype; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Ubiquinone

Oxidative stress is defined as a disturbance in the prooxidant-antioxidant balance in favor of the former and has been suggested to be a relevant factor in aging as well as in different pathological conditions, such as heart attack, diabetes, and cancer. Ubiquinol is very sensitive against oxygen radicals and gives ubiquinone as an oxidation product. Therefore, the ratio of ubiquinol to ubiquinone should be a good marker of oxidative stress because of its definition. A method for the simultaneous detection of ubiquinol-10 and ubiquinone-10 in human plasma is described. Heparinized human plasma was mixed with 5 volumes of methanol and 10 volumes of hexane. After vigorous shaking and centrifugation, the hexane phase (5 microliters) was injected immediately and directly on to reverse-phase HPLC equipped with an on-line reduction column and an electrochemical detector in order to avoid the oxidation of ubiquinol to ubiquinone. It was found that the ratio of ubiquinol-10 to ubiquinone-10 was about 95/5 in human plasma from healthy donors. A significant increase in the oxidized form (ubiquinone-10) content was observed in plasmas of patients with hepatitis, cirrhosis, and hepatoma when compared with normal subjects, suggesting increased oxidative stress in these patients.

Topics: Biomarkers; Carcinoma, Hepatocellular; Chromatography, High Pressure Liquid; Coenzymes; Electrochemistry; Hepatitis; Hexanes; Humans; Liver Cirrhosis; Liver Diseases; Liver Neoplasms; Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species; Solvents; Ubiquinone; Vitamin E