DNA microarray analysis of gene expression in steady-state chemostat cultures limited for potassium revealed a surprising connection between potassium and ammonium: potassium limits growth only when ammonium is the nitrogen source. Under potassium limitation, ammonium appears to be toxic for Saccharomyces cerevisiae. This ammonium toxicity, which appears to occur by leakage of ammonium through ...

Cholesterol is an essential component of lysosomal membranes. In this study, we investigated the effects of membrane cholesterol on the permeability of rat liver lysosomes to K+ and H+, and the organelle stability. Through the measurements of lysosomal beta-hexosaminidase free activity, membrane potential, membrane fluidity, intra-lysosomal pH, and lysosomal proton leakage, we established that ...

effective microorganisms (em) is a commercial biofertilizer mainly consists of photosynthetic and lactic acid bacteria, yeast and actinomycetes. in order to evaluate the influence of em (0 and %1) and salt stress (0 mm, 50 mm, 100 mm and 150 mm) on the morphophysiological characteristics of pomegranate cv. shishe-kap, a factorial experiment was conducted based on the completely randomized desig...

Effects of the antiepileptic drug valproate on sodium and potassium currents in the nodal membrane of peripheral nerve fibers of Xenopus laevis were determined by voltage- and current-clamp experiments. Under voltage-clamp conditions, a reduction of both sodium and potassium conductance (in a ratio of 2:1) was observed. Typically, 2.4 mM (400 mg/L) valproate reduced the sodium current 54% and t...

The polyene antibiotic candicidin produces a rapid efflux of K(+) ions from a suspension of Candida albicans. Onset of K(+) leakage depends on the culture age, stationary-phase yeasts leaking K(+) more slowly than exponential-phase yeasts. The time taken for potassium leakage to begin represents the time taken by the antibiotic to cross the cell wall and produce membrane damage. It was shown th...

Mode-of-action studies concluded that alkyldimethylbenzylammonium chloride (ADBAC) (a blend of C(12), C(14) and C(16) alkyl homologues) and didecyldimethylammonium chloride (DDAC) are both membrane-active agents, possessing subtly different modes of action reflecting early cell interactions against Staphylococcus aureus. ADBAC and DDAC exhibited similar MIC behaviors from 0.4 ppm to 1.8 ppm ove...

AIMS Evaluation of the cellular effects of Origanum compactum essential oil on Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 29213. METHODS AND RESULTS The damage induced by O. compactum essential oil on these two strains has been studied using different techniques: plate count, potassium leakage, flow cytometry (FC) and transmission electron microscopy (TEM). The results s...