Endosymbiont biosynthesis of norharmane in Reticulitermes termites (Isoptera: Rhinotermitidae)
Endosymbiont biosynthesis of norharmane in Reticulitermes termites (Isoptera: Rhinotermitidae)
复制标题
散白蚁（等翅目：鼻白蚁科）内共生去甲哈烷的生物合成
作者：
M. Siderhurst;D. James;T. Blunt;L. Bjostad
虽然已知白蚁含有荧光生物碱去甲哈尔烷，但这种化合物的生理分布和生物合成来源以前没有报道。紫外光下的组织学观察表明，去甲哈尔烷是包含在白蚁的内部流体。这与去甲哈尔烷在蝎子中的生理分布相反，其中生物碱包含在上表皮中。GC/MS分析表明，去甲哈尔烷主要位于血淋巴中，去除血淋巴会导致白蚁尸体中所有可观察到的荧光丧失。GC/MS分析进一步表明，去甲哈尔烷是从离体培养的胫散白蚁和红胸散白蚁内共生菌中合成的代谢产物。黄足白蚁放线菌是白蚁肠道的组成部分，也是已知唯一能产生去甲哈尔烷的微生物，因此放线菌可能是合成去甲哈尔烷的内共生体。
Although termites are known to contain the fluorescent alkaloid norharmane, the physiological distribution and biosynthetic origin of this compound has not previously been reported. Histological observations under UV light showed that norharmane is contained in the termite internal fluids. This is in contrast to the physiological distribution of norharmane in scorpions, in which the alkaloid is contained in the epicuticle. GC/MS analyses showed that norharmane is mainly located in the hemolymph with hemolymph removal causing the loss of all observable fluorescence in termite carcasses. GC/MS analyses further showed that norharmane was biosynthesized as a metabolite from endosymbionts cultured in isolation from Reticulitermes tibialis and R. flavipes termites. Actinomycetes bacteria are likely candidates as the endosymbionts that biosynthesize norharmane, because they are components of the termite gut and are the only microbes known to produce norharmane.