In Saccharomyces cerevisiae, acetate is formed by acetaldehyde dehydrogenase (ACDH), a key enzyme of the pyruvate dehydrogenase (PDH) bypass, which fulfils the essential task of generating acetyl-CoA in the cytosol. The role of the five members of the ACDH family (ALD genes) was investigated during anaerobic growth on glucose. Single and multiple ald Delta mutants were generated in the wine-yea...

The thermophilic methanogen Methanosaeta thermophila uses acetate as sole substrate for methanogenesis. It was proposed that the acetate activation reaction that is needed to feed acetate into the methanogenic pathway requires the hydrolysis of two ATP, whereas the acetate activation reaction in Methanosarcina sp. is known to require only one ATP. As these organisms live at the thermodynamic li...

Few mutations attenuate Mycobacterium tuberculosis (Mtb) more profoundly than deletion of its isocitrate lyases (ICLs). However, the basis for this attenuation remains incompletely defined. Mtb's ICLs are catalytically bifunctional isocitrate and methylisocitrate lyases required for growth on even and odd chain fatty acids. Here, we report that Mtb's ICLs are essential for survival on both acet...

Ammonia concentration is one of the key factors influencing the methanogenic community composition and dominant methanogenic pathway in anaerobic digesters. This study adopted a radiolabelling technique using [2-14C] acetate to investigate the relationship between total ammonia nitrogen (TAN) and the methanogenic pathway. The radiolabelling experiments determined the ratio of 14CO2 and 14CH4 in...

Lactococcus lactis metabolizes glucose homofermentatively to lactate. However, after disruption of the gene coding for lactate dehydrogenase, LDH , a key enzyme in NAD regeneration, the glycolytic flux shifts from homolactic to mixed-acid fermentation with the redirection of pyruvate towards production of formate, acetate, ethanol and CO2. A mathematical model of the pyruvate metabolism pathway...

The marine bacterium Vibrio fischeri uses two acyl-homoserine lactone (acyl-HSL) quorum-sensing systems. The earlier signal, octanoyl-HSL, produced by AinS, is required for normal colonization of the squid Euprymna scolopes and, in culture, is necessary for a normal growth yield. In examining the latter requirement, we found that during growth in a glycerol/tryptone-based medium, wild-type V. f...

The [H(+)]-catalyzed dissociation rate constants of several trivalent lanthanide (Ln) complexes of 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (LnDO2A(+), Ln = La, Pr, Eu, Er and Lu) have been determined in two pH ranges: 3.73-5.11 and 1.75-2.65 at four different temperatures (19-41.0 °C) in aqueous media at a constant ionic strength of 0.1 mol dm(-3) (LiClO(4)). For the study in the highe...

Biomass from two full-scale anaerobic digester treating different wastes regarding to nitrogen concentrations and operating under different hydraulic retention time was characterized by methanogenic batch activity assays at different ammonia concentrations. Two several different patterns regarding activity and microbial parameters was demonstrated depending on operational conditions and methano...