Pynyaha Y. Development of the transformation system of the flavinogenic yeast Pichia guillermondii

Object of research: RF biosynthesis and the regulation of this process in the yeast of P. guilliermondii. The aim of the work: development of the transformation system of the flavinogenic yeast P. guillermondii to clone of regulatory genes which participate in riboflavin biosynthesis regulation. Methods: microbiological, molecular genetics, biochemical, mathematical statistics. We have developed transformation systems of P. guilliermondii, based on URA3 gene of S. cerevisiae and FES1 gene of P. guilliermondii as a selective markers and ura3 and fes1mutants of P. guilliermondii as a recipient strains, correspondingly. It was selected the knock-out mutants of P. guilliermondii with deleted of RIB1, RIB7, YFH1, FES1 and VMA1 genes. It was shown, that yeast frataxin homolog (Yfh1p) participates in the RF biosynthesis regulation, iron homeostasis and sulfate assimilation in P. guilliermondii yeast. An insertion mutagenesis system for P. guilliermondii was developed to clone of regulatory genes which participate in riboflavin biosynthesis regulation. It was found, that VMA1 gene is involved in the RF biosynthesis regulation and iron homeostasis in P. guilliermondii. Area of use: microbiology, genetics, biotechnology, biochemistry.