微生物产生的土腥味化合物及其清除方法

自然界中存在许多具有土腥味的化合物,以Geosmin和MIB为代表,它们的嗅阈值极低,即便含量极微,也能嗅到浓烈的土腥味、土臭味、泥土味和霉味。这些土腥味挥发性物质主要是放线菌和藻类的次生代谢产物,不同生物具有不同的合成途径。它们极易影响饮用水的品质,也给渔业和食品业带来极大危害。通过物理、化学和生物处理等方法,可以控制或清除土腥味化合物,其中微生物降解法是最有应用前景的净化方法。综述了土腥味化合物的来源、生物合成途径、分析检测技术及净化方法。

Earthy-smelling Compounds Produced by Microorganisms and the Smell-removing Measures

Geosmin and MIB are well-known scent compounds w ith a characteristic musty, earthy odor reminiscent of freshly ploughed soil, wh ich are produced by certain Actinomyces and alga that inhabit aquatic and soil e nvironment. They have an extremely low odor threshold, so that trace amount of t hese substances can be detected by human noses. They are known to impart nauseou s "off-flavors" to potable water, food and aquaculture-raised fish, causing serious economical losses. Physical, chemical and bioloical measures are used to remove earthy odor. Of which, biodegradation is one of the most promising means . A general outline of these scent compounds produced by microorganisms, the bio logical synthesis pathways, analysis and detection methods and removal measures were given.