Transcription of the nrdDG operon, which encodes the class III nucleotide reductase, which is only active under anaerobic conditions, was strongly induced after a shift to anaerobiosis. The induction was completely dependent on the transcriptional activator FNR and was independent of the ArcA-ArcB two-component response regulator system. The nrdD transcript start site was mapped to a position i...

While establishing methods for the control of spoilage in the tartrate recovery plants of California, Vaughn et al. (1943a,b; 1946) isolated a number of D-tartrate-decomposing microorganisms, including several mesophilic clostridia. These organisms, among the most active fermenters of D-tartrate, are of historical as well as economic interest, for it was in a tartrate medium that Pasteur (1863)...

Protein and operon fusions between the manganese superoxide dismutase (MnSOD) gene, sodA, and genes of the lactose operon were constructed in an attempt to explore the effects of various factors on MnSOD expression and the level at which they operate. In sodA-lacZ protein fusions, induction of beta-galactosidase perfectly mimicked MnSOD induction (i.e., beta-galactosidase was not expressed in a...

The physiological nature of photoinduced germination of Onoclea sensibilis L. spores was investigated by temporarily applying a range of temperatures, particularly 40 C, before and after short light treatment. Controls were germinated at 25 C.The preinduction phase, during which photosensitivity is maximally developed in the dark, is sensitive to temperature. Treatment at 40 C for 8 or more hou...

Twelve 4- and 5-nitroimidazole derivatives, including metronidazole and two of its metabolites, tinidazole, dimetridazole, and nimorazole, were tested for antitrichomonad action on Tritrichomonas foetus (KV(1)) and Trichomonas vaginalis (ATCC 30001) for mutagenicity on a nitroreductase-positive (TA 100) and a nitroreductase-deficient (TA 100-FR(1)) strain of Salmonella typhimurium, as well as f...

Adaptive changes in energy metabolism, as reflected by pyruvate kinase and cytochrome oxidase activities, were examined during in vitro differentiation of the cultivated macrophage. Serum concentrations of tissue culture media, which directly influence endocytic activity, and ambient oxygen tension were both shown to influence pyruvate kinase and cytochrome oxidase activities. Cells maintained ...

The diarrheal potential of a Bacillus cereus strain is essentially dictated by the amount of secreted nonhemolytic enterotoxin (Nhe). Expression of genes encoding Nhe is regulated by several factors, including the metabolic state of the cells. To identify metabolic sensors that could promote communication between central metabolism and nhe expression, we compared four strains of the B. cereus g...

BACKGROUND Understanding the effects of oxygen levels on yeast xylose metabolism would benefit ethanol production. In this work, xylose fermentative capacity of Scheffersomyces stipitis, Spathaspora passalidarum, Spathaspora arborariae and Candida tenuis was systematically compared under aerobic, oxygen-limited and anaerobic conditions. RESULTS Fermentative performances of the four yeasts wer...

It was reported previously that enolase enzyme activity and ENO1 transcript levels are induced by anaerobic stress in maize (Zea mays). Here we show that not all isoforms of maize enolase are anaerobically induced. We cloned and sequenced a second enolase cDNA clone (pENO2) from maize. Sequence analysis showed that pENO2 shares 75.6% nucleotide and 89.5% deduced amino acid sequence identity wit...

1. The duration of maximal activity and the intensity of anaerobic metabolismwere measured in lowland Sceloporus occidentalis at low (200 ft) and high (10,150 ft) elevations and compared to those of resident S. occidentalis and S. graciosus at high altitude. 2. The duration of maximal activity is independent of altitude: all groups of S. occidentalis had the same stamina, regardless of the alti...