Yeast protein-surfactant complexes uncouple microbial electron transfer and increase transmembrane leak of protons.

Aims: To explore the combined effect of yeast proteins and surfactants on bacterial metabolism.

Methods And Results: Protein-rich cell-free supernatant from heat-shocked yeast Saccharomyces cerevisiae was combined with certain synthetic surfactants. These blends affected the metabolism of a Polyseed inoculum of aerobic bacteria, accelerating CO(2) production and consumption of nutrients from a sterile nutrient broth solution, without a concomitant accumulation of biomass.

The effects of a diet rich in docosahexaenoic acid on organ and vascular fatty acid composition in spontaneously hypertensive rats.

Previous research has shown that dietary docosahexaenoic acid (DHA) attenuates the development of high blood pressure in young spontaneously hypertensive rats (SHR). The purpose of this study was to investigate the effects of dietary DHA on organ and vascular fatty acid composition in SHR. Given the important structural and functional role of fatty acids in cell membranes, alterations in fatty acid composition may contribute to the antihypertensive effect of DHA.

Absence of transitory [Ca2+]i flux during early in vitro metacyclogenesis of Trypanosoma cruzi.

The phorbol ester TPA (phorbol 12-myristate 13-acetate) substitutes for CO2 as an agonist for transforming Trypanosoma cruzi epimastigotes to the metacyclic trypomastigote stage in a starvation medium consisting of phosphate buffered saline + 10 mM proline, 10 mM sodium acetate and 0.035% NaHCO3. Since TPA is thought to stimulate protein kinase C by mimicking the activity of the secondary messenger diacylglycerol, the above result suggested that T.

Action of exogenous potassium and calcium ions on in vitro metacyclogenesis in Trypanosoma cruzi.

The cations Ca2+ and K+ and the anions Cl-, HCO3-, and PO4- were studied for their contribution to metacyclic trypomastigote formation of Trypanosoma cruzi in starvation media consisting of phosphate-buffered saline (PBS) + 10 mM proline + 10 mM sodium acetate as well as one of the following salts: 0.035% NaHCO3 (PBSNPA), 0.035% K2CO3 (PBSKPA) or 0.

Further studies on substrates inducing metacyclogenesis in Trypanosoma cruzi.

Epimastigotes of Trypanosoma cruzi, Peru strain, incubated in Contreras' artificial triatomine urine transformed into metacyclic trypomastigotes when 10 mM L-glutamine, L-asparagine or D-fructose was added to the medium. Metacyclogenesis with these substrates was comparable to the percent metacyclic morphotype formation induced by L-proline and significantly greater than that stimulated by 10 mM D-glucose. Sodium acetate (10 mM) increased transformation induced by L-proline, and L-hydroxyproline (10 mM) increased transformation induced by D-fructose.