Learning Chemistry

Fermentation  is a metabolic process that consumes sugar in the absence of oxygen. The products are organic acids, gases, or alcohol. It occurs in  yeast  and  bacteria , and also in oxygen-starved muscle cells, as in the case of  lactic acid fermentation . The science of fermentation is known as  zymology . In microorganisms, fermentation is the primary means of producing ATP by the degradation of organic nutrients  anaerobically . Humans have used fermentation to produce drinks and beverages since the  Neolithic age . For example, fermentation is used for preservation in a process that produces  lactic acid  as found in such sour  foods  as  pickled cucumbers ,  kimchi  and  yogurt  (see  fermentation in food processing ), as well as for producing alcoholic beverages such as  wine  (see  fermentation in winemaking ) and  beer . Fermentation occurs within the gastrointe...

The term antibiotics is a broad one , defined by Waksman as, "a substance produced by microorganisms , which has the capacity of inhibiting the growth and even of destroying other microorganisms by the action of very small amounts of the antibiotics " . Approximately 3000 substances come under the classification , but only 70 have the necessary combination of patient safety , antimicrobial action and stability. Penicillin, erythromycin, tetracycline, cephalosporins are among the most widely used. Penicillin : A number of penicillin, differing only in the composition of the R ( alkyl ) group, have been isolated from natural media and hundreds have been semi-synthesized . Penicillin G USP, with benzyl for R group, generally the most desirable , is the type commercially available , usually combined in salt form with procaine or potassium.  It is possible to assist the synthesis of a desired penicillin by supplying the appropriate precursor to the culture i.e., the acid of ...