Department of Applied Biological Chemistry, School of Agriculture, Utsunomiya University, Tochigi, Japan.
Biosci Biotechnol Biochem. 2021 May 25;85(6):1530-1535. doi: 10.1093/bbb/zbab039.
Geraniol is one of the important aromatic ingredients in alcoholic beverages. Bioconversions of geraniol to other terpenoids and genes involved in the oxidation of geraniol were investigated. Geranic acid and citronellic acid were detected in yeast culture, where geraniol or nerol was added. Addition of citral, a mixture of geranial and neral, resulted in the production of geranic acid and citronellic acid, whereas the addition of citral or citronellal resulted in the production of citronellic acid, suggesting that citronellic acid might be produced through the conversion of citral to citronellal followed by the oxidation of citronellal. Consumption of geraniol and production of geranic acid, citronellic acid, and citronellol were affected in adh1Δ, adh3Δ, adh4Δ, and sfa1Δ yeast strains, which possess single deletion of a gene encoding alcohol dehydrogenase. This is the first report of the bioconversion of monoterpene alcohols, geraniol and nerol, to geranic acid and citronellic acid in yeast culture.
香叶醇是酒精饮料中的一种重要芳香成分。本研究对香叶醇的生物转化为其他萜类化合物以及参与香叶醇氧化的基因进行了研究。在添加香叶醇或橙花醇的酵母培养物中检测到了橙花酸和香茅酸。添加柠檬醛（香叶醛和橙花醛的混合物）会导致橙花酸和香茅酸的生成，而添加柠檬醛或香茅醛只会导致香茅酸的生成，这表明香茅酸可能是通过柠檬醛转化为香茅醛，然后再氧化为香茅醛而产生的。在adh1Δ、adh3Δ、adh4Δ 和 sfa1Δ 酵母菌株（分别缺失编码醇脱氢酶的单个基因）中，香叶醇和橙花醇的消耗以及橙花酸、香茅酸和香茅醇的生成受到影响。这是首次报道在酵母培养物中通过生物转化单萜醇，香叶醇和橙花醇，生成橙花酸和香茅酸。
