著者

関口 順一

出版者

日本生物工学会

雑誌

醗酵工学会誌 (ISSN:03856151)

巻号頁・発行日

vol.61, no.3, pp.p129-137, 1983-05

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Patulin is a typical mycotoxin originally isolated from Penicillium patulum as an antibiotic, and the patulin biosynthetic pathway is a classical example of the large group of polyacetate-dervied secondary metabolites known as polyketides. Unexpected metabolites produced by a patulin-deficient mutant revealed a new portion of the pathway. We have investigated the patulin biosynthetic pathway with the aid of several patulin-deficient mutants, pathway enzymology, bioconvesion of metabolites, and immobilized cell techniques. It was found that three mycotoxins (phyllostine, isoepoxydon and ascladiol) and a new lactone (neopatulin) exist on the pathway. Two dehydrogenases among the pathyway enzymes were characterized. Furthemore, in contrast to the accepted assumption, monooxygenase mediated the ring cleavage of an aromatic precursor, gentisaldehyde. Finally, the patulin pathway becomes twice as long as the portion known before 1978,and is one of the best characterized pathways of secondary metabolism. In this monograph, mechanisms of the conversion of phyllostine to neopatulin, and neopatulin to phyllostine, are proposed, and a pathway for the related mycotoxin, penicillic acid, is also discussed.

著者

小泉 武夫 角田 潔和 原 高教 鈴木 明治

出版者

日本生物工学会

雑誌

醗酵工学会誌 (ISSN:03856151)

巻号頁・発行日

vol.56, no.6, pp.p745-751, 1978-11

被引用文献数

1

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In the previous paper (Hakkokogaku 55 : 167-174,1977), we trapped koji-aroma components on coconut-shell sctivated carbon attached to the air exhaust of an automatic koji-making machine. By this method, chemically neutral components, 9 alcohols, 23 esters and 9 carbonyl compounds, were detected. This paper deals with the volatile organic acids and amines in koji-aroma adsorbed on activated carbon. These components were extracted with a mixture of ether and n-pentane from the carbon and esparated with ion exchange resins.The fraction of volatile organic acids was analyzed by gas chromatography and carboxylic acid analyzer and five volatile organic acids, acetic, propionic, butyric, caleric and caproic acids were found, of which acetic acid was predominant. The volatile amine fraction was analyzed by thin layer chromatography and gas chromatography. Three volatile amines, ethlamine, i-butylamine and i-amylamine were identified in koji-aroma absorbed on carbon.In addition, tetramethylenediamine, ethanolamine, pentamethylenediamine and β-phenyl-ethylamine were detected in rice koji by extraction with ethanol.

著者

栗山 一秀 芦田 晋三 斉藤 義幸 秦 洋二 杉並 孝二 今安 聰

出版者

日本生物工学会

雑誌

醗酵工学会誌 (ISSN:03856151)

巻号頁・発行日

vol.64, no.3, pp.p175-180, 1986-05

被引用文献数

1

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It has been believed that in sake ethyl caproate is one of the main component of ginjo-flavour. There have been no reports about the synthesis and hydrolysis of ethyl caproate. We have studied the activity of sake yeast in the synthesis and hydrolysis of ethyl caproate. The results obtained are as follows : 1) The esterase of Saccharomyces cerevisiae on ethyl caproate synthesis was separated into three fractions (S-I, II, III) by Sepharose 6B gel filtration. 2) The esterase fraction of ethyl caproate synthesis (S-II, III) did not hydrolyze p-nitrophenyl acetatte, so it was impossible to examine the esterase activity by this method. The esterase activity of ethyl caproate synthesis and hydrolysis must be measured by gas chromatography.3) The optimum pH of the esterase of ethyl caproate synthesis was 5.0,and that of ethyl caproate hydrolysis was 10.0. 4) The optimum pH of alcohol acyltransferase was 8.0. 5) There were differences in the localization of esterase and alcohol acyltransferase in the cells. Therefore, there are two pathways to the formation of ethyl caproate through esterase and through alcohol acyltransferase.6) The esterase fraction S-II was stabilized by ammonium sulfate.