Advances in citric acid fermentation by Aspergillus niger: Biochemical aspects, membrane transport and modeling

Research Review Paper

Maria Papagianni ⁎
Department of Hygiene and Technology of Food of Animal Origin, School of Veterinary Medicine, Aristotle University of Thessaloniki,
54006 Thessaloniki, Greece
Received 8 October 2006; received in revised form 11 January 2007; accepted 11 January 2007
Available online 19 January 2007

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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 acid has continued to attract interest even though its commercial production by fermentation has been established for decades. Although extensive basic biochemical research has been carried out with A. niger, the understanding of the events relevant for citric acid accumulation is not completely understood. This review is focused on citric acid fermentation by A. niger.

Emphasis is given to aspects of fermentation biochemistry, membrane transport in A. niger and modeling of the production process.

© 2007 Elsevier Inc. All rights reserved.

PDF: Advances in citric acid fermentation by Aspergillus niger: Biochemical aspects, membrane transport and modeling

Additional reading-PDF: Comparative genomics of citric-acid-producing
Aspergillus niger ATCC 1015 versus enzyme-producing
CBS 513.88

Horace Fletcher-The Great Masticator

Content Source ~ Wikipedia

Horace Fletcher (1849–1919) was an American health food enthusiast of the Victorian era who earned the nickname “The Great Masticator”, by arguing that food should be chewed about 100 times per minute before being swallowed: “Nature will castigate those who don’t masticate”. He made elaborate justifications for his claim.

  1. Eat only when you have a good appetite.
  2. Chew the food like pulp and drink that pulp. Do not swallow food.
  3. Drink all the liquids and liquid food sip by sip. Do not drink in gulps.

Fletcher and his followers recited and followed his instructions religiously, even claiming that liquids, too, had to be chewed in order to be properly mixed with saliva. Fletcher argued that his mastication method will increase the amount of strength a person could have while actually decreasing the amount of food that he consumed. Fletcher promised that “Fletcherizing”, as it became known, would turn “a pitiable glutton into an intelligent epicurean.”

EPICURUS ~ Wikipedia ~ For Epicurus, the purpose of philosophy was to attain the happy, tranquil life, characterized by ataraxia—peace and freedom from fear—and aponia—the absence of pain—and by living a self-sufficient life surrounded by friends. He taught that the root of all human neurosis was death denial, and the tendency for human beings to assume that death will be horrific and painful, which he claimed causes unnecessary anxiety, selfish self-protective behaviors, and hypocrisy. According to Epicurus, death is the end of both the body and the soul and therefore should not be feared. He also taught that the gods neither reward nor punish humans; that the universe is infinite and eternal; and that occurrences in the natural world are ultimately the result of atoms moving and interacting in empty space.