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...

The effect of Nickel doped Cobalt ferrite nano particles Ni0.2CoxFe2-x04(x=0.1, 0.2, 0.3, 0.5) Created by sol-gel auto combustion technique using citric acid as fuel. single phase cubic structure form confirm the XRD. crystalline size calculated FWHM (311) plane Scherer’s formula. typicalsize sample varies in order regime. structural and lattice parameter were obtained XRD data. surface morphol...

Three types of methods have been proposed for the determination of citric acid in urine. Salant and Wise (1) used the unspecific mercuric sulfate reagent of Deniges (2) in a study of the toxicity of citrates. Thunberg (3) developed an enzymatic method employing a dehydrogenase said to be specific for citrate. The remaining methods depend on the so called pentabromoacetone method of Stahre (4), ...

pollution arising from plastic waste materials caused a great worry for researchers who are interested in protection of environment. this problem shifts their subject to bio-polymers for applications in packaging industries. however, their low water barrier properties are a critical problem. the effects of citric acid and methyl cellulose on water vapor and oxygen permeabilities and mechanical ...