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''Ogataea polymorpha'' is a methylotrophic yeast with unusual characteristics. It is used as a protein factory for pharmaceuticals. ''Ogataea polymorpha'' belongs to a limited number of methylotrophic yeast species – yeasts that can grow on methanol. The range of methylotrophic yeasts includes ''Candida boidinii'', ''Pichia methanolica'', ''Pichia pastoris'' and ''Ogataea polymorpha''. ''O. polymorpha'' is taxonomically a species of the Saccharomycetaceae family. ==Strains== Three ''O. polymorpha'' strains, identified in the 1950s, are known. They have unclear relationships and are of independent origins. They are found in soil samples, the gut of insects or in spoiled concentrated orange juice. They exhibit different features and are used in basic research and to recombinant protein production: *strain CBS4732 (CCY38-22-2; ATCC34438, NRRL-Y-5445) *strain DL-1 (NRRL-Y-7560; ATCC26012) *strain NCYC495 (CBS1976; ATAA14754, NRLL-Y-1798) Strains CBS4732 and NCYY495 can be mated whereas strain DL-1 cannot be mated with the other two. Strains CBS4732 and DL-1 are employed for recombinant protein production, strain NCYC495 is mainly used for the study of nitrate assimilation. The entire genome of strain CBS4732 has completely been sequenced. ''Ogataea polymorpha'' is a thermo-tolerant microorganism with some strains growing at temperatures above . The organism is able to assimilate nitrate and can grow on a range of carbon sources in addition to methanol. Cells grown under conditions of elevated temperature accumulate a sugar named trehalose (this sugar is usually found in insects) as thermo-protective compound. It was shown that trehalose synthesis is not required for growth under these conditions, but for acquisition of thermotolerance. The synthetic steps for trehalose synthesis have been detailed for ''O. polymorpha'', and ''TPS1'', the key enzyme gene of this pathway, has been isolated and characterized. All methylotrophic yeasts share an identical methanol utilization pathway (Fig. 1). Growth on methanol is accompanied by a massive proliferation of cell organelles named peroxisomes in which the initial enzymatic steps of this pathway take place. ''O. polymorpha'' is model organism to study all aspects of peroxisomal functions and the underlying molecular biology. During growth on methanol key enzymes of the methanol metabolism are present in high amounts. An especially high abundance can be observed for enzymes called MOX (methanol oxidase), FMDH (formate dehydrogenase), and DHAS (dihydroxyacetone synthase). Their presence is regulated at the transcriptional level of the respective genes. In the related species ''C. boidinii'', ''P. methanolica'', and ''P. pastoris'' this gene expression strictly depends on the presence of methanol or methanol derivatives, whereas in ''O. polymorpha'' strong expression is elicited by appropriate levels of glycerol or under conditions of glucose starvation. ''O. polymorpha'' produces glycoproteins with two types of sugar chains, N- and O-linked glycans are attached to protein. Studies on the structure of N-linked chains have revealed a certain average length (Man8-12GlcNAc2) with terminal alpha-1,2-linked mannose residues, and not with allergenic terminal alpha-1,3-linked mannose residues as found in other yeasts, especially in the baker’s yeast ''Saccharomyces cerevisiae''. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ogataea polymorpha」の詳細全文を読む スポンサード リンク
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