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Fermentative production of 5′‐purine ribonucleotide
Author(s) -
Nara T.,
Misawa M.,
Kinoshita S.
Publication year - 1968
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260100304
Subject(s) - hypoxanthine , ribonucleotide , biochemistry , chemistry , fermentation , yield (engineering) , mutant , acetoin , inosine , nucleotide , inosine monophosphate , adenosine , enzyme , materials science , metallurgy , gene
Micrococcus sodonensis KY 3765 and Arthrobacter citreus KY 3155 were found capable of accumulating IMP in media supplemented with hypoxanthine as a precursor. High concentrations of phosphate and magnesium salts were required for high yields of IMP. Manganese deficiency in the media was also essential. Excessive Mn 2+ effects were also seen in the IMP fermentation carried out with an adenineless mutant, of Cornynebacterium glutamicum . In M. sodonensis , R5P‐like substances, 5‐phosphoribose pyrophosphokinase and IMP pyrophosphorylase, were leaked out, of the cells grown in suboptimal Mn 2+ levels. This excretion was inhibited by high levels of Mn 2+ . Such a phenomenon was not noted in A. citreus. An adenineless mutant (KY 7208) of Brevibacterium ammoniagenes was found to accumulate an appreciable amount of IMP. The chemical changes in this fermentation showed that, hypoxanthine was first produced de novo , excreted, and then reconverted into IMP by a salvage pathway. When hypoxanthine was added to 7208 culture, IMP yield was increased appreciably. In fact exogenous 14 C‐hypoxanthine was incorporated into 14 C‐IMP. Subsequent experiments showed that indeed Br. ammoniagenes ATCC 6872, a parent culture of KY 7208, was able to produce IMP, GMP, and AMP, in good yield from hypoxanthine, guanine, and adenine, respectively.