Dahlen T, Hauck T, Wein M, Schwab W
Lehrstuhl für Lebensmittelchemie, Universität Würzburg, 97074 Würzburg, Germany.
J Biosci Bioeng. 2001;91(4):352-8. doi: 10.1263/jbb.91.352.
2,5-Dimethyl-4-hydroxy-3(2H)-furanone (DMHF) is an important aroma compound found in many fruits such as strawberries and pineapples and it is also produced by the soy-sauce-fermenting yeast Zygosaccharomyces rouxii after the addition of d-fructose-1,6-diphosphate to yeast-peptone-dextrose nutrient media. Dilute DMHF solutions exhibit a strawberry-like flavor while DMHF concentrates have a caramel-like aroma. In media containing D-fructose-1,6-diphosphate as the sole carbon source, growth of Z. rouxii and formation of DMHF were not observed. Although Z. rouxii cells grew in media with D-glucose as the sole carbon source, DMHF was only produced when media were supplemented with D-fructose-1,6-diphosphate. The DMHF concentration always correlated with the yeast cell count and D-fructose-1,6-diphosphate concentration. Addition of CaCl2 (up to 50 g.l(-1)) led to a higher DMHF concentration. Addition of Na2SO3 reduced the growth of Z. rouxii and inhibited DMHF formation. The amount of DMHF formed by Z. rouxii was not significantly affected by the addition of KH2PO4. DMHF concentrations of 5 and 10 g.l(-1) partially and completely inhibited the growth of Z. rouxii cells, respectively. Only the singly labeled furanone was formed after the addition of 1-13C-D-fructose-1,6-diphosphate to the medium. However, unlabeled DMHF was formed in the presence of (13)C(6)-D-glucose. Therefore, the carbons of the furanone originate exclusively from exogenously supplied D-fructose-1,6-diphosphate as no exchange with the internal pool of D-fructose-1,6-diphosphate occurs. This implies that DMHF is a secondary metabolite of Z. rouxii formed from D-fructose-1,6-diphosphate. We assume that at least the first step of the metabolism of D-fructose-1,6-diphosphate takes place in the cell wall or membrane of the yeast.
2,5-二甲基-4-羟基-3(2H)-呋喃酮（DMHF）是一种重要的香气化合物，存在于许多水果中，如草莓和菠萝，酱油发酵酵母鲁氏接合酵母在酵母蛋白胨葡萄糖营养培养基中添加d-果糖-1,6-二磷酸后也会产生这种化合物。稀释的DMHF溶液具有类似草莓的风味，而DMHF浓缩物具有类似焦糖的香气。在以d-果糖-1,6-二磷酸作为唯一碳源的培养基中，未观察到鲁氏接合酵母的生长和DMHF的形成。尽管鲁氏接合酵母细胞在以d-葡萄糖作为唯一碳源的培养基中生长，但只有在培养基中添加d-果糖-1,6-二磷酸时才会产生DMHF。DMHF浓度始终与酵母细胞计数和d-果糖-1,6-二磷酸浓度相关。添加CaCl2（高达50 g·l(-1)）会导致更高的DMHF浓度。添加Na2SO3会降低鲁氏接合酵母的生长并抑制DMHF的形成。添加KH2PO4对鲁氏接合酵母形成的DMHF量没有显著影响。5 g·l(-1)和10 g·l(-1)的DMHF浓度分别部分和完全抑制了鲁氏接合酵母细胞的生长。向培养基中添加1-13C- d-果糖-1,6-二磷酸后，仅形成了单标记的呋喃酮。然而，在(13)C(6)-d-葡萄糖存在的情况下形成了未标记的DMHF。因此，呋喃酮的碳完全来自外源供应的d-果糖-1,6-二磷酸，因为与内部的d-果糖-1,6-二磷酸池没有发生交换。这意味着DMHF是鲁氏接合酵母由d-果糖-1,6-二磷酸形成的次生代谢产物。我们假设d-果糖-1,6-二磷酸代谢的至少第一步发生在酵母的细胞壁或细胞膜中。
