In water microcosm experiments, the survival times of Campylobacter isolates differed by up to twofold, as determined by culturing; this difference increased to fourfold when particular combinations of temperature and oxygenation were used. The mean survival times were much longer at 4 and 10 degrees C (202 and 176 h, respectively) than at 22 and 37 degrees C (43 and 22 h, respectively). The in...

To live anaerobically an organism must generate its energy and synthesize its substance without recourse to molecular 02. Thus any discussion of the biochemistry of anaerobiosis must centre on what alternatives there are to aerobic respiration and oxygenic photosynthesis as means of biological energy conservation, and to what extent an anaerobe is constrained by being denied the facility of exp...

Many yeasts can aerobically catabolize exogenously supplied glycosides that are hydrolysed in the cytosol, but few do so anaerobically. This is so, even for yeasts that use one or more of the component hexoses anaerobically. The phenomenon, called the Kluyver effect, appears to be brought about by a combination of the following four factors: (i) fast transport of the glycosides into the cells i...

Brucella abortus causes brucellosis mainly in cattle. The infection is transmitted to humans by ingestion of animal products or direct contact with infected material. While the intracellular lifestyle of Brucella is well characterized, its extracellular survival is poorly understood. In nature, bacterial persistence is associated with biofilms, where aggregated cells are protected from adversit...

With the recent development of powerful molecular genetic tools, Kluyveromyces lactis has become an excellent alternative yeast model organism for studying the relationships between genetics and physiology. In particular, comparative yeast research has been providing insights into the strikingly different physiological strategies that are reflected by dominance of respiration over fermentation ...

Rice (Oryza sativa) seeds were imbibed for 3 days and the seedlings were further incubated for 8 days in the presence of either air or nitrogen. In aerobiosis, the specific activity of pyrophosphate:fructose 6-phosphate 1-phosphotransferase and that of the ATP-dependent phosphofructokinase increased about fourfold. In anaerobiosis, the specific activity of ATP-dependent phosphofructokinase rema...

Hydrogen peroxide treatment induces the synthesis of 30 proteins in Salmonella typhimurium. Five of these proteins are also induced by heat shock, including the highly conserved DnaK protein. The induction of one of these five proteins by heat shock is dependent on oxyR, a positive regulator of hydrogen peroxide-inducible genes, while the induction of the other four by heat shock is oxyR indepe...

Lactobacillus sakei is a lactic acid bacterium belonging to the natural flora of meat products. It constitutes the main flora of vacuum-packed meat and is largely used in western Europe as a starter for the manufacturing of fermented sausages. This species is able to grow both under aerobiosis and anaerobiosis. In many technological processes involving it, oxygen is scarce. The aim of this stud...