[Localization of the genes coding for GTP cyclohydrolase II and riboflavin synthase on the chromosome of Escherichia coli K-12].

A conjugation analysis of riboflavin-dependent mutants of Escherichia coli K-12 has been made by means of various F'-factors. It is shown that the GTP cyclohydrolase II gene is localized in the chromosome map site between 27 and 30 min; the riboflavin synthase gene--in the site between 56 and 59 min; and the gene in which mutation causes accumulation of 2,6-dioxy-5-amino-4-ribitylamino-pyrimidine--in the site limited by 61-65 min. So it may be concluded that riboflavin biosynthesis genes in the E.

[Flavinogenesis regulation in riboflavin-dependent Escherichia coli mutants].

355 Escherichia coli mutants requiring riboflavin (RF) for their growth were selected using N-methyl-N-nitro-N-nitrosoguanidine. The mutants were subdivided into four biochemical groups according to their capability to accumulate fluorescent pigments in the medium and their nature, the ability to grow in a medium containing either diacetyl or 6,7-dimethyl-8-ribityl lumazine (DMRL), and the activity of GTP cyclohydrolase II and RF synthase. The rate of RF accumulation by the parent strain of E.

[Purification and properties of Pichia guilliermondii yeast alkaline nucleotide pyrophosphatase hydrolyzing flavin adenine dinucleotide].

Alkaline nucleotide pyrophosphatase was isolated from the Pichia guilliermondii Wickerham ATCC 9058 cell-free extracts. The enzyme was 740-fold purified by saturation of ammonium sulphate, gel-chromatography on Sephadex G-150 and ion-exchange chromatography on DEAE-cellulose. Nucleotide pyrophosphatase is the most active at pH 8.

[Purification and properties of the Pichia guilliermondii acid nucleotide pyrophosphatase hydrolyzing flavin adeninine dinucleotide].

Acid nucleotide pyrophosphatase was isolated from the cell-free extracts of Pichia guilliermondii Wickerham ATCC 9058. The enzyme was 25-fold purified by saturation with ammonium sulphate, gel-filtration on Sephadex G-150 column and ion-exchange chromatography on DEAE-Sephadex A-50 column. The pH optimum was 5.