Publications by authors named "Hiroaki Okuhara"

To enhance the value of surimi, efforts have been made to develop a fermentation method with lactic acid bacteria (LAB) to proteolyze fish protein. However, fermenting unheated surimi poses a spoilage risk due to its high bacterial content. Surimi heat treatment can prevent spoilage, but gel formation induced by heating introduces another technical issue: it hinders uniform fermentation.

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The complete genome sequence of (LVX), which infects lilies, was determined for the first time from lilies in Japan. As with previous reports, the genome of the Japanese LVX isolate lacked an AUG start codon for the triple gene block protein 3-like region.

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Ceramide is one of the most important intercellular components responsible for the barrier and moisture retention functions of the skin. Because of the risks involved with using products of animal origin and the low productivity of plants, the availability of ceramides is currently limited. In this study, we successfully developed a system that produces sphingosine-containing human ceramide-NS in the yeast Saccharomyces cerevisiae by eliminating the genes for yeast sphingolipid hydroxylases (encoded by SUR2 and SCS7) and introducing the gene for a human sphingolipid desaturase (encoded by DES1).

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In plants, O-methyltransferases (OMTs) play an important role in methylation of secondary metabolites, especially flavonoids and other phenylpropanoids, and two cDNA clones, IhOMT1 and IhOMT2 (Iris hollandica OMT), encoding OMTs were successfully isolated from a cDNA library of flower buds of I. hollandica. IhOMT1 encodes an open reading frame (ORF) of 365 amino acids with calculated molecular mass of 40,193Da and isoelectric point (pI) of 5.

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Bright blue or red flowers in the Japanese morning glory (Ipomoea nil) contain anthocyanidin 3-O-sophoroside derivatives, whereas the reddish-brown or purplish-gray petals in its dusky mutants accumulate anthocyanidin 3-O-glucoside derivatives. The Dusky gene was found to encode a novel glucosyltransferase, UDP-glucose:anthocyanidin 3-O-glucoside-2''-O-glucosyltransferase (3GGT), which mediates the glucosylation of anthocyanidin 3-O-glucosides to yield anthocyanidin 3-O-sophorosides. Ipomoea nil carries one copy of the 3GGT gene that contains no intron and produces 1.

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Gentian (Gentiana triflora) blue petals predominantly contain an unusually blue and stable anthocyanin, delphinidin 3-O-glucosyl-5-O-(6-O-caffeoyl-glucosyl)-3'-O-(6-O-caffeoyl-glucoside) (gentiodelphin). Glucosylation and the subsequent acylation of the 3'-hydroxy group of the B-ring of anthocyanins are important to the stabilization of and the imparting of bluer color to these anthocyanins. The enzymes and their genes involved in these modifications of the B-ring, however, have not been characterized, purified, or isolated to date.

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