JOINT INFLUENCE OF MUTATIONS RIB80 AND HIT ON RIBOFLAVIN
BIOSYNTHESIS AND FERRIREDUCTASE ACTIVITY
IN YEAST PICHIA GUILLIERMONDII
T.M.Romanyuk, D.V.Fedorovóch, O.V.Protchenko, S.P.Gudz
Institute of Biochemistry, National Academy of Sciences
Drahomanov St. 14/16, Lviv, 79005, Ukraine
Pichia guilliermondii mutant strains defective in both of RIB80 and HIT regulatory genes of negative type of action involved in control of riboflavin biosynthesis and iron transport have been isolated by means of hybridization rib80 and hit mutants and subsequent selection of meiotic segregants. Most of them possessed elevated levels of riboflavin biosynthesis and enhanced activity of enzymes participating in vitamin B2 biosynthesis. Obtained data indicates that rib80 and hit mutations interact by synergistic manner. The presence of both mutation in one genome did not affect on ferrireductase activity by the cells.
Key words: riboflavin biosynthesis, yeast, iron transport, ferrireductase activity.
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