Episodic acidification resulting in increased acidity and inorganic aluminum (Al(i)) is known to interfere with the parr-smolt transformation of Atlantic salmon (Salmo salar), and has been implicated as a possible cause of population decline. To determine the extent and mechanism(s) by which short-term acid/Al exposure compromises smolt development, Atlantic salmon smolts were exposed to either...

A teichuronopeptide (TUP) is one of major structural components of the cell wall of the facultative alkaliphilic strain Bacillus lentus C-125. A mutant defective in TUP synthesis grows slowly at alkaline pH. An upper limit of pH for growth of the mutant was 10.4, while that of the parental strain C-125 was 10.8. Gene tupA, directing synthesis of TUP, was cloned from C-125 chromosomal DNA. The p...

The tolerance of 26 Bacillus species isolated from alkaline fermented foods, five other bacilli and nine non spore-forming bacteria to alkaline pH and ammonia was determined. All grew at pH 7, 8 and 9 in the presence of 930 mmol l-1 NH4 + at pH 7.0, and in the presence of NH3 concentrations up to 5 mmol l-1 at pH 7.0 and 8.0. At higher NH3 concentrations, growth of some of the bacteria was inhi...

Left heart failure is currently the most prevalent cause of pulmonary hypertension (PH) worldwide and this is due mainly to the increased left ventricular and pulmonary venous pressures seen in this condition. Still, a quota of patients with left heart failure will have a pulmonary arterial disease "disproportionate" to the initial increase of left-sided pressures. Whatever the mechanism involv...

1. Modelling analysis of intravenous glucose tolerance test glucose and insulin concentrations can provide measures of insulin sensitivity and metabolism from a single straightforward procedure. However, little is known of the effects of blood arterialization on model-derived parameters. 2. Intravenous glucose tolerance tests were carried out on 18 subjects, with measurement of glucose and insu...

The medium pH level of plant tissue cultures has been shown to be essential to many aspects of explant development and growth. Sensitivity or tolerance of medium pH change varies according to specific requirements of in vitro individual species. The objectives of this study are to 1) determine medium pH change over time in storage conditions and with presence of explants, 2) evaluate the effect...

There is a large variation in the tolerance of myocardial tissue to cellular acidosis. Assuming the cytoplasmic acid-base status to be mainly a result of intracellular processes, this variation could be produced by variations in the tissue non-bicarbonate buffer value. In the myocardial tissue from nine vertebrate species, the non-bicarbonate buffer value did not correlate either with ability t...

The induction of acid-shock proteins and the degree of acid resistance conferred on Clostridium perfringens by acid shock, and the kinetics of this resistance were determined. A sublethal acid shock at pH 4.5 for 20 min increased the acid tolerance of cells at least fifteenfold. The acquired tolerance was maintained for 3 h after acid treatment. The response of the microorganism to acid shock w...

The selection of potential probiotic strains that possess the physiological capacity performing successfully in gastrointestinal tract (GIT) is a critical challenge. Probiotic microorganisms must tolerate deleterious effects various stresses to survive passage and function human GIT. Adhesion intestinal mucosa also an important aspect. Recently, numerous studies have been performed concerning e...

The isolated dog heart has been shown to function without significant impairment when perfused with physiological solutions of varied pH values between 7.0 and 7.8 (1). Recently it was demonstrated that the dog heart in situ may function without serious impairment until a blood pH value of 6.25 is attained by infusion of hydrochloric or lactic acid into the circulating blood (2). This value app...