Measurement of the flux through the citrate fermentation pathway in resting cells of Lactococcus lactis CRL264 grown in a pH-controlled fermentor at different pH values showed that the pathway was constitutively expressed, but its activity was significantly enhanced at low pH. The flux through the citrate-degrading pathway correlated with the magnitude of the membrane potential and pH gradient ...

Bacillus licheniformis ATCC 9945a is one of the bacterial strains that produce gamma-poly(glutamic acid) (gamma-PGA). The use of carbohydrate medium components for gamma-PGA production was explored. Cells were grown in shake flasks or in controlled pH fermentors using medium formulations that contain different carbon sources. During the cultivations, aliquots were removed to monitor cell growth...

Response surface methodology was used to optimize media components such as carbon and nitrogen (simple and complex) sources, mineral agents and growth factors (B vitamins, amino acids) for enhancing the biomass production of Lactobacillus rhamnosus PEN. For screening experiment the following carbon sources were selected: glucose, glucose+pyruvate, glucose+citrate, glucose+lactate, galactose, fr...

In this study we describe the expression pattern of the Leuconostoc paramesenteroides citMCDEFGRP operon in response to the addition of citrate to the growth medium. An 8.8-kb polycistronic transcript, which includes the citMCDEFGRP genes, was identified; its synthesis was dramatically induced upon addition of citrate to the growth medium. We also found that expression of the cit operon is subj...

An agar medium containing arginine and calcium citrate as specific substrates, diffusible (K(2)HPO(4)) and undiffusible (CaCO(3)) buffer systems, and bromocresol purple as the pH indicator was developed to differentiate among lactic streptococci in pure and mixed cultures. Milk was added as the sole source of carbohydrate (lactose) and to provide growth-stimulating factors. Production of acid f...

The present study was designed to assess whether citrate stimulates aldosterone production by isolated bovine adrenal glomerulosa cells in vitro. When the cells were incubated with graded concentrations of citrate up to 4.0 mM, basal aldosterone production was significantly elevated, with a gradual reduction of extracellular ionized calcium concentration. Without citrate, however, adding increa...

Mycoplasma pneumoniae harvested from media which had become acid lost the ability both to induce formation of tetrazolium reduction inhibition antibody and to act as antigens in immunodiffusion against human convalescent-phase sera. Incorporation of N-tris(hydroxymethyl)-2-aminoethane sulfonic acid and N-2-hydroxyethylpiperazine-N'-2-ethane sulfonic acid buffers into a new medium containing PPL...

fienoniycin is a new polyene antibiotic produced by Actinomyces distatochromogenes var. lienomycini, exhibiting antifungal, antibacterial and antitumor activity [l-4] . It changes the plasma membrane permeability characteristics of sensitive organisms [5] . The present report deals with so far unobserved sensitivity of rat-liver mitochondria to lienomycin. The antibiotic stimulates mitochondria...

and production of streptomycin by Actinomyces streptomycini is postulated to involve NADPglycohydrolase (E. C. 3. 2. 2. 6)4>. A-factor was reported to stimulate the formation of NADPglycohydrolase in Str-Amymutants and the product, phospho-adenosinediphosphoribose, was found to act as a competitive inhibitor of the enzymes of carbohydrate catabolism4> and the citrate cycles' during development ...

Citrate metabolism in Leuconostoc mesenteroides subspecies mesenteroides is associated with the generation of a proton motive force by a secondary mechanism (C. Marty-Teysset, C. Posthuma, J. S. Lolkema, P. Schmitt, C. Divies, and W. N. Konings, J. Bacteriol. 178:2178-2185, 1996). The pathway consists of four steps: (i) uptake of citrate, (ii) splitting of citrate into acetate and oxaloacetate,...