We examined the effects of citric acid and l-carnitine administration on physical fatigue. In a double-blind, placebo-controlled, 3-way crossover study, 18 healthy volunteers were randomized to oral citric acid (2,700 mg/day), l-carnitine (1,000 mg/day), or placebo for 8 days. The fatigue-inducing physical task consisted of workload trials on a cycle ergometer at fixed workloads for 2 h on 2 oc...

In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan, and hydroxyl propyl methyl cellulose (HPMC) as the liquid phase and tetra calcium phosphate (TTCP), dicalcium phosphate dihydrate (DCPD) and calcium sulfate dehydrate (CSD, CaSO4 x 2H2O) powders as the solid phase, were fabricated. Two groups were classified based on the percent of citric acid in the liquid ...

S t e i n b e r g (1935) and L u n d (1953) found that the growth of Aspergillus niger is influenced by copper. O r 1 o v et al. (1968) have further observed that 10.0% solution of copper sulphate increases markedly the yield of citric acid when molasses is employed as substrate. T o m l i n s o n et al (1950) studied the influence of Zn, Fe, Mn and Cu on the production of citric acid and obser...

Fungi isolated from various rotten fruits and vegetables were screened for the capability of producing citric acid. Aspergillus niger (A. niger) was obtained in the decayed onion peels and denoted as KON13 and this fungi strain was used in the production of citric acid by submerged fermentation. Critical process parameters affecting the fermentative citric acid production were investigated, inc...

Citric acid is a commodity chemical produced and consumed throughout The World. It is used mainly in the food and beverage industry, primarily as an acidulant. Although it is one of the oldest industrial fermentations, its World production is still in rapid increasing. Global production of citric acid in 2007 was over 1.6 million tones. Biochemistry of citric acid fermentation, various microbia...

We have shown that crude, cell-free extracts of Aspergillus terreus contain aconitase and cis-aconitic decarboxylase, and therefore quantitatively decarboxylate cis-aconitic, citric, and d-isocitric acids to itaconic acid and CO2 (1, 2). With use of labeled substrates, it has been shown that the isotope distributions in itaconic acid are consistent with the formation of cis-aconitic acid from c...

Citric acid is regarded as a metabolite of energy metabolism, of which the concentration will rise to appreciable amounts only under conditions of substantive metabolic imbalances. Citric acid fermentation conditions were established during the 1930s and 1940s, when the effects of various medium components were evaluated. The biochemical mechanism by which Aspergillus niger accumulates citric a...

The present study is concerned with the effect of low pH on continuous citric acid fermentation by Aspergillus niger strain SK-17. Microbial cultivations were carried out in a stainless steel stirred bioreactor of 15 L total capacity. The bioconversion of glucose to citric acid at low pH was investigated on cellulose fabric. Sucrose solution (100 g/l) was made to flow through capillaries of a v...