| 摘要 |
Adenosine di- and tri-phosphates and guanosine di- and tri-phosphates are prepared by culturing a bacterium of the Brevibacterium ammoniagenes species in a nutrient medium which contains a carbon source nitrogen source, inorganic salts and natural or organic products containing nitrogen, under aerobic conditions preferably at a temperature from 20 DEG to 40 DEG C. in the presence in the nutrient medium of adenine or adenosine or of guanine or guanosine respectively until there has been an accumulation of the di- and tri-phosphates in the medium and thereafter recovering the said phosphates. For the stabilization of the growth of the bacteria, amino acids and vitamins such as biotin, thiamine, pantothenic acid or substances which have the same physiological significance, e.g. b -alanine and coenzyme A may be added. Suitable carbon sources are carbohydrates such as glucose and hydrolysis products of starch or molasses, suitable nitrogen sources are urea, ammonium chloride and ammonium nitrate, suitable inorganic salts are the potassium phosphates, magnesium sulphate and calcium chloride and suitable natural products containing nitrogen are corn steep liquor, yeast extract, meat extract, peptone, casamino acids and fish solubles. For good yields the concentration of inorganic phosphate added to the medium should be between 0.4% and 1.6% by weight, calculated as PO4. The culturing may comprise a first phase which is carried out in the absence of adenine, adenosine, guanine or guanosine and a second phase which continues at a pH of 5.5 to 7.5 after the addition of any of these compounds to the culture medium. A neutralizing agent such as aqueous sodium hydroxide may be used to maintain the preferred pH value of the culture medium.
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