| immunological identification and distribution of dissimilatory heme cd1 and nonheme copper nitrite reductases in denitrifying bacteria. | polyclonal antibodies were used to identify heme or copper nitrite reductases in the following groups: 23 taxonomically diverse denitrifiers from culture collections, 100 numerically dominant denitrifiers from geographically diverse environments, and 51 denitrifiers from a culture collection not selected for denitrification. antisera were raised against heme nitrite reductases from pseudomonas aeruginosa and pseudomonas stutzeri and against copper nitrite reductase from achromobacter cycloclaste ... | 1989 | 2624465 |
| nitrate-dependent regulation of acetate biosynthesis and nitrate respiration by clostridium thermoaceticum. | nitrate has been shown to shunt the electron flow in clostridium thermoaceticum from co2 to nitrate, but it did not influence the levels of enzymes involved in the wood-ljungdahl pathway (j. m. fröstl, c. seifritz, and h. l. drake, j. bacteriol. 178:4597-4603, 1996). here we show that under some growth conditions, nitrate does in fact repress proteins involved in the wood-ljungdahl pathway. the co oxidation activity in crude extracts of nitrate (30 mm)-supplemented cultures was fivefold less tha ... | 1999 | 10049380 |
| characterization of ichthyocidal activity of pfiesteria piscicida: dependence on the dinospore cell density. | the ichthyocidal activity of pfiesteria piscicida dinospores was examined in an aquarium bioassay format by exposing fish to either pfiesteria-containing environmental sediments or clonal p. piscicida. the presence of pfiesteria spp. and the complexity of the microbial assemblage in the bioassay were assessed by molecular approaches. cell-free water from bioassays that yielded significant fish mortality failed to show ichthyocidal activity. histopathological examination of moribund and dead fish ... | 2005 | 15640229 |
| free-living heterotrophic nitrogen-fixing bacteria isolated from fuel-contaminated antarctic soils. | five bacterial isolates enriched from fuel-contaminated antarctic soils fixed nitrogen in the dark heterotrophically and nonsymbiotically. two isolates utilized jet fuel vapors and volatile hydrocarbons for growth but not in n-deficient medium. bacteria such as these may contribute to in situ biodegradation of hydrocarbons in antarctic soils. | 2002 | 12324373 |
| microbial communities in the chemocline of a hypersaline deep-sea basin (urania basin, mediterranean sea). | the urania basin is a hypersaline sulfidic brine lake at the bottom of the eastern mediterranean sea. since this basin is located at a depth of approximately 3,500 m below the sea surface, it receives only a small amount of phytoplankton organic carbon. in the present study, the bacterial assemblages at the interface between the hypersaline brine and the overlaying seawater were investigated. the sulfide concentration increased from 0 to 10 mm within a vertical interval of 5 m across the interfa ... | 2001 | 11722884 |
| elemental composition of bacterial metachromatic inclusions determined by electron microprobe x-ray analysis. | electron microscopy and microprobe x-ray analysis were used to study metachromatic inclusions of spirillum itersonii , corynebacterium diphtheriae, and micrococcus luteus. in situ metachromatic inclusions were electron dense and contained phosphorus and divalent cations. metachromatic inclusions isolated by anion-exchange column chromatography and by isoosmolar metrizamide density gradient centrifugation were similar in composition to in situ inclusions. | 1984 | 6427179 |
| nitrous oxide formation in the colne estuary, england: the central role of nitrite. | nitrate and nitrite concentrations in the water and nitrous oxide and nitrite fluxes across the sediment-water interface were measured monthly in the river colne estuary, england, from december 1996 to march 1998. water column concentrations of n(2)o in the colne were supersaturated with respect to air, indicating that the estuary was a source of n(2)o for the atmosphere. at the freshwater end of the estuary, nitrous oxide effluxes from the sediment were closely correlated with the nitrite conce ... | 2002 | 11872474 |
| criteria and methodology for identifying respiratory denitrifiers. | respiratory denitrification is not always adequately established when bacteria are characterized. we have tested a simple method that allows one to evaluate whether the two necessary criteria to claim denitrification have been met, namely, that n(inf2) or n(inf2)o is produced from nitrate or nitrite and that this reduction is coupled to a growth yield increase. microorganisms were cultured in sealed tubes under a helium headspace and in the presence of 0, 2, 4, 7, and 10 mm nitrate or nitrite. a ... | 1995 | 16534960 |
| iron reductase for magnetite synthesis in the magnetotactic bacterium magnetospirillum magnetotacticum. | ferric iron reductase was purified from magnetotactic bacterium magnetospirillum (formerly aquaspirillum) magnetotacticum (atcc 31632) to an electrophoretically homogeneous state. the enzyme was loosely bound on the cytoplasmic face of the cytoplasmic membrane and was found more frequently in magnetic cells than in nonmagnetic cells. the molecular mass of the purified enzyme was calculated upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be about 36 kda, almost the same as that ... | 1999 | 10094692 |
| impact of a novel protein meal on the gastrointestinal microbiota and the host transcriptome of larval zebrafish danio rerio. | larval zebrafish was subjected to a methodological exploration of the gastrointestinal microbiota and transcriptome. assessed was the impact of two dietary inclusion levels of a novel protein meal (npm) of animal origin (ragworm nereis virens) on the gastrointestinal tract (git). microbial development was assessed over the first 21 days post egg fertilization (dpf) through 16s rrna gene-based microbial composition profiling by pyrosequencing. differentially expressed genes in the git were demons ... | 2015 | 25983694 |
| the lysr-type transcription factor hbrl is a global regulator of iron homeostasis and porphyrin synthesis in rhodobacter capsulatus. | the purple bacterium rhodobacter capsulatus is unique among rhodobacteriacae as it contains a putative iron response regulator (irr) but does not possess a copy of the ferric uptake regulator (fur). interestingly, an in-frame deletion mutant of irr shows no major role in iron homeostasis. instead, we showed that the previously identified activator of haem gene expression hbrl is a crucial regulator of iron homeostasis. we demonstrated that an hbrl deletion strain is unable to grow in iron-limite ... | 2013 | 24134691 |