Biosynthesis of the Off-Flavor 2-Methylisoborneol by the Myxobacterium Nannocystis exedens
Biosynthesis of the Off-Flavor 2-Methylisoborneol by the Myxobacterium Nannocystis exedens
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DOI：
10.1002/anie.200702496
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发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Schulz, Stefan
中科院分区：
文献类型：
--
作者：
Dickschat, Jeroen S.;Nawrath, Thorben;Schulz, Stefan
细菌通常不被认为是对我们环境的气味有重大贡献的生物体。然而，许多细菌产生不同物质类别的挥发物，例如脂肪酸衍生物、芳香族化合物、氮和硫化合物或萜类化合物。[1]这些气味可以发挥重要的生态作用，例如影响人类和其他生物的行为。链霉菌和粘细菌释放出高度复杂的挥发物，[2-7]而常见的发霉或土味萜类化合物2-甲基异戊烯（1）和土臭素（2）具有极低的气味阈值。化合物1是一种同单萜，首先在淡紫链霉菌中发现[8]，后来在其他几种放线菌，[6，9]蓝藻，[10]真菌，[11]和地钱中发现，在那里它以（β）-对映体出现。[12]特别是蓝细菌会导致淡水污染，产生不希望的味道（异味）1，这可能导致渔业的重大经济损失。[13]此外，低浓度的1（10 ng LIPO 1）会导致恶臭的饮用水，这是强烈排斥的人。[14]这样的浓度是无毒的，但令人反感的气味可能会导致身心影响，如头痛，胃部不适或压力。[第十五条]
Bacteria are generally not regarded as organisms that contribute significantly to odors of our environment. Nevertheless, many bacteria produce volatiles of different substance classes, such as fatty acid derivatives, aromatic compounds, nitrogen and sulfur compounds, or terpenoids.[1] These odors can play important ecological roles, such as influencing the behavior of humans and other organisms. Highly complex profiles of volatiles are emitted by streptomycetes and myxobacteria,[2–7] and the frequently found musty or earthy smelling terpenoids 2-methylisoborneol (1) and geosmin (2) have extremely low odor thresholds. Compound 1, a homomonoterpene, was first identified in Streptomyces lavendulae,[8] and later in several other actinomycetes,[6, 9] cyanobacteria,[10] fungi,[11] and a liverwort, where it occurs as the (À)-enantiomer.[12]Especially cyanobacteria can cause contaminations of freshwater with the undesirable flavor (off-flavor) 1, that can result in significant economic losses in fishery.[13] Furthermore, low concentrations of 1 (10 ng LÀ1) cause malodorous drinking water that is strongly rejected by humans.[14] Such concentrations are not toxic, but the offensive odor may lead to psychosomatic effects, such as headaches, stomach upsets, or stress.[15]