柠檬醛顺反异构体对黄曲霉超微结构及膜功能的影响

Effect of cis-trans Isomer of Citral on Microstructure and Membrane Function of A. flavus

研究柠檬醛顺反异构体(香叶醛和橙花醛)抗菌性是阐明该醛抗菌机理核心所在.用酶转化法合成香叶醛和橙花醛后,用液态或气态的异构单体分别对黄曲霉孢子及菌丝体进行毒化.采用透射电镜、多维显微及激光拉曼散射技术对毒化的黄曲霉孢子及菌丝体进行显微结构观察和膜相关参数的测定.结果表明,无论是液体还是气体毒化方式,柠檬醛顺反异构体单独存在时均有抗黄曲霉作用;二者混合物的抗菌总活性与单体相比表现出一定程度协同性;二个异构单体的抗菌作用不仅表现为破坏黄曲霉超微结构,而且还反映在损伤其细胞膜体积调节功能及变形能力.

It is important to clarify the antibacterial effects of citral on Aspergillus flavus by investigating its cis-trans isomers. In the current study, geranial and neral, citral＇s isomers, were synthesized by enzyme catalysis. Following the poison by liquid and gaseous isomer, the microstructures of spore and mycelium of A. flavus were observed, The correlative parameters of cell membrane were measured by transmission electron microscope, multiplex microanalysis and co-focus laser Raman microanalysis techniques. The results revealed that citral isomer poisoned by either liquid or gaseous manner could separately be effective on inhibition to A. flavous. Meanwhile synergistic inhibition effect was observed in the form of mixture of two citral isomers compared with the effect of isomer. The results also indicated that two isomers might exert its antibacterial action by destroying the microstructure of A. flavous and the cell membrane function in adjusting volume and transfiguration.