Mechanism of electron transport during thiosulfate oxidation in an obligately mixotrophic bacterium Thiomonas bhubaneswarensis strain S10 (DSM 18181T).

This study describes the thiosulfate-supported respiratory electron transport activity of Thiomonas bhubaneswarensis strain S10 (DSM 18181T). Whole-genome sequence analysis revealed the presence of complete sox (sulfur oxidation) gene cluster (soxCDYZAXB) including the sulfur oxygenase reductase (SOR), sulfide quinone reductase (SQR), sulfide dehydrogenase (flavocytochrome c (fcc)), thiosulfate dehydrogenase (Tsd), sulfite dehydrogenase (SorAB), and intracellular sulfur oxidation protein (DsrE/DsrF). In addition, genes encoding respiratory electron transport chain components viz. complex I (NADH dehydrogenase), complex II (succinate dehydrogenase), complex III (ubiquinone-cytochrome c reductase), and various types of terminal oxidases (cytochrome c and quinol oxidase) were identified in the genome. Using site-specific electron donors and inhibitors and by analyzing the cytochrome spectra, we identified the shortest thiosulfate-dependent electron transport chain in T. bhubaneswarensis DSM 18181T. Our results showed that thiosulfate supports the electron transport activity in a bifurcated manner, donating electrons to quinol (bd) and cytochrome c (Caa 3 ) oxidase; these two sites (quinol oxidase and cytochrome c oxidase) also showed differences in their phosphate esterification potential (oxidative phosphorylation efficiency (P/O)). Further, it was evidenced that the substrate-level phosphorylation is the major contributor to the total energy budget in this bacterium.

Utilization of cytologic cell blocks for targeted sequencing of solid tumors.

BACKGROUND: Targeted sequencing of cytologic samples has significantly increased in recent years. With increasing numbers of clinical trials for variant specific therapeutics, validating a comprehensive assay for cytologic samples has become clinically important. AIM: For this study, a retrospective review of cytologic cell blocks from fine needle aspirations and fluid specimens was performed. METHODS: Two hundred twenty six total cases of solid tumor malignancies were identified, of which 120 cases and 20 lymph node negative controls were sequenced for the Oncomine Comprehensive Assay. Cytology and surgical specimen correlation was performed in a subset of cases. Statistical analysis to determine variant concordance was performed. RESULTS: Within the 117 cases sequenced, a total of 347 pathogenic variants were detected. Of the 117 cases, 32 cases (27.4%) would qualify for FDA approved targeted therapy according to the current guidelines, and an additional 23 cases (19.7%) would qualify for clinical trial based on pathogenic variants detected. DISCUSSION: With over 27% of cases in our cohort qualifying for some form of targeted therapy, our study shows the importance of providing comprehensive molecular diagnostic options. Despite only half of the cytology cases in the review period having enough material to be sequenced, overall approximately 27% of patients in this cohort would have benefitted from this service.

Characterization of Comamonas thiooxidans sp. nov., and comparison of thiosulfate oxidation with Comamonas testosteroni and Comamonas composti.

Comamonas thiooxidans (strain S23(T)) capable of oxidizing thiosulfate under a mixotrophic growth condition was isolated from a sulfur spring. DNA-DNA homology study showed 55% similarity with Comamonas testosteroni KCTC2990(T) and 52% with Comamonas composti LMG24008(T), the nearest phylogenetic relative (16S rRNA sequence similarity <97%). Comparative genomic fingerprinting by using ERIC and Rep-PCR further delineated species identity of the strain S23(T) for which Comamonas thiooxidans sp. nov. is proposed. In addition, thiosulfate oxidation potential of the strain S23(T) was compared with Comamonas testosteroni and Comamonas composti.

Thiosulfate oxidation by Comamonas sp. S23 isolated from a sulfur spring.

A bacterial isolate S23 capable of oxidizing thiosulfate was isolated from a sulfur spring. Strain S23 is gram-negative, aerobic, and motile. The G + C content of DNA is 61.4 mol%. The fatty acid composition and phylogenetic analysis of the 16S rRNA gene sequence of strain S23 showed that it is related to the members of the genus Comamonas, and most closely related to Comamonas testosteroni (99.9% sequence similarity). The isolate S23 exhibited thiosulfate oxidation under a mixotrophic growth condition. Polymerase chain reaction (PCR) using soxB-specific primers and DNA sequencing showed the presence of the soxB gene. This is the first report in Comamonas sp. showing thiosulfate oxidation under a mixotrophic growth condition.

Draft Genome Sequence of Gulbenkiania indica Strain HT27T (DSM 17901T) Isolated from a Sulfur Spring in India.

Gulbenkiania indica strain HT27(T) was isolated from a sulfur spring. Here, we report the first representative draft genome sequence of a type strain of the genus Gulbenkiania The estimated genome is 2.8 Mb, with 2,713 protein-coding sequences.

Draft Genome Sequence of Comamonas thiooxydans Strain S23T (DSM 17888T), a Thiosulfate-Oxidizing Bacterium Isolated from a Sulfur Spring in India.

The genus Comamonas contains species isolated from various environments, such as termite guts, wetlands, activated sludge, soil, humans, and fresh water. Here, we report the draft genome sequence of Comamonas thiooxydans strain S23(T) capable of oxidizing thiosulfate under mixotrophic growth conditions. Based upon draft genome sequencing, the genome is 5.3 Mb and encodes 4,767 proteins. The Comamonas thiooxydans whole-genome sequence will help understand the metabolic diversity in sulfur oxidation pathways.

Gulbenkiania indica sp. nov., isolated from a sulfur spring.

A novel bacterium, designated strain HT27(T), was isolated from a sulfur spring sample collected from Athamallik, Orissa, India, and was characterized by using a polyphasic approach. Cells were Gram-negative, strictly aerobic, rod-shaped and motile by means of a single polar flagellum. Strain HT27(T) was oxidase- and catalase-positive. Growth was observed at pH 5.0-11.0 and at 15-45 degrees C; the highest growth yield was observed at pH 7.5-8.0 and 30-37 degrees C. The G+C content of the genomic DNA of strain HT27(T) was 63 mol%. The major cellular fatty acids were C(16 : 1)omega7c (44.24 %), C(16 : 0) (27.65 %), C(18 : 1)omega7c (13.98 %), C(12 : 0) (2.60 %) and C(12 : 0) 3-OH (2.22 %). 16S rRNA gene sequence analysis indicated that strain HT27(T) clustered with the genus Gulbenkiania and showed 99.0 % similarity to Gulbenkiania mobilis E4FC31(T). However, the level of DNA-DNA relatedness between strain HT27(T) and G. mobilis E4FC31(T) was 30 %. On the basis of phenotypic and chemotaxonomic characteristics, 16S rRNA gene sequence analysis and DNA-DNA hybridization data, strain HT27(T) is considered to represent a novel species of the genus Gulbenkiania, for which the name Gulbenkiania indica sp. nov. is proposed. The type strain is HT27(T) (=DSM 17901(T) =JCM 15969(T)).