Production of Flavour‐enhancing Materials by Streptomycetes: Factors affecting the Production 5′‐Mononucleotides

Schwartz, Joseph A.; Margalith, P.

doi:10.1111/j.1365-2672.1972.tb03676.x

Cited by 2 publications

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References 18 publications

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“…5 The following modifications were also employed: Medium B = medium A + 2.5% corn steep liquor (54% solids); medium C = medium A + 0.1 sodium barbitone.…”

Section: Media and Cultivationmentioning

confidence: 99%

Binding of end product in the fermentation of nucleotides

Schwartz

Margalith

1973

Biotech & Bioengineering

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SummaryFlavor enhancing nucleotides may be produced by streptomycetes. Mutants of streptomyces 772 were found to produce, under ordinary fermentation conditions, considerable amounts of 5'-IMP and 5'-XMP, but only traces of 5'-GMP. This was probably due to the feedback inhibition of the end product GMP. I t was shown that through suitable fermentation techniques it was possible to overcome this internal control mechanism, leading to increased yields of 5'-GMP.

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“…5 The following modifications were also employed: Medium B = medium A + 2.5% corn steep liquor (54% solids); medium C = medium A + 0.1 sodium barbitone.…”

Section: Media and Cultivationmentioning

confidence: 99%

Binding of end product in the fermentation of nucleotides

Schwartz

Margalith

1973

Biotech & Bioengineering

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Production of Flavour‐Enhancing Materials by Streptomycetes: Strain Improvement and Fermentation*

Schwartz

Margalith

1972

Journal of Applied Bacteriology

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SuimraRY. Mutation work and the adaptation of streptomycete 772 to certain antimct,abolites resulted in increased production of 5'-nucleotides, including 5'.guanylic acid (5'-GMP), concerned with flavour potentiation. The formation of each nucleotide was considerably affect,ed by the composition of the medium. Na barbitone increased the biosynthesis of B'-inosinic acid by blocking the pathway t o 5'-GMP, while the 8-azaguanine adapted strains were no longer sensitive to the action of the drug. These results are discussed in view of the current concepts of metabolic control mechanisms. , 1971, 1972) the possibility of producing flavour potentiators (5'-nucleotides) by streptomycetes was investigated. Employing a suitable screening procedure, a number of streptomycetes was isolated which showed substantial accumulation of 5'-inosinic acid (5'-IMP) and 5'-xanthylic acid (5'-XMP) under ordinary fermentation conditions. Organism 772 was superior, yielding up to 0.8 g/1 of Na,IMP and 0.2 g/1 'of Na,XMP, in conventional media. These results were considerably improved when special fermentation conditions were employed.With high manganese concentrations (200 mg/l) levels of 1.7 g/l of IMP and 0.4 g/l of XMP were obtained, while in the presence of barbituates (0.1 %), 3*2g/l of lMP and 0.2 g/1 of XMP were formed. An additional improvement could be achieved by adding antibiotics to the medium : in some cases this also led to the excretion of minor amounts of 5'-guanylic acid (5'-GMP). The latter compound is rarely produced abundantly because of an intracellular control mechanism that inhibits the formation of the end product in the biosynthesis of this nucleotide (Demain, 1968). In this paper, strain improvement and factors affecting fermentation by the improved strains will be dealt with. Materials and MethodsStrain improvement Mutants were obtained by UV irradiation of streptomycete 772, employing a suspension of conidia at a concentration of c. 108/ml of saline. Irradiation was effected by a Hannau NN30/89 lamp, a t 30 cm from the surface of the suspension and 150 sec duration, with continuous agitation. Samples were plated on a complete medium, Oatmeal agar (Difco I.S.P. medium No. 3 ; supplemented with 0.05% of yeast extract).

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Production of Flavour‐enhancing Materials by Streptomycetes: Factors affecting the Production 5′‐Mononucleotides

Cited by 2 publications

References 18 publications

Binding of end product in the fermentation of nucleotides

Binding of end product in the fermentation of nucleotides

Production of Flavour‐Enhancing Materials by Streptomycetes: Strain Improvement and Fermentation*

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