Department of Microbiology, School of Biology, University College of Sciences, University of Tehran, Enghelab Avenue, 14176-14411, Tehran, Iran.
Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Arch Microbiol. 2020 Aug;202(6):1317-1325. doi: 10.1007/s00203-020-01835-w. Epub 2020 Mar 5.
In this study, relationship between translucent property of yeast cell wall and occurrence of cyanobacteria inside the yeast vacuole was examined. Microscopic observations on fruit yeast Candida tropicalis showed occurrence of bacterium-like bodies inside the yeast vacuole. Appearance of vacuoles as distinct cavities indicated the perfect harvesting of light by the yeast's cell wall. Transmission electron microscopy observation showed electron-dense outer and electron-lucent inner layers in yeast cell wall. Cyanobacteria-specific 16S rRNA gene was amplified from total DNA of yeast. Cultivation of yeast in distilled water led to excision of intracellular bacteria which grew on cyanobacteria-specific medium. Examination of wet mount and Gram-stained preparations of excised bacteria showed typical bead-like trichomes. Amplification of cyanobacteria-specific genes, 16S rRNA, cnfR and dxcf, confirmed bacterial identity as Leptolyngbya boryana. These results showed that translucent cell wall of yeast has been engineered through evolution for receiving light for vital activities of cyanobacteria.
在这项研究中，研究了酵母细胞壁的半透明性质与酵母液泡内蓝藻发生之间的关系。对热带假丝酵母（Candida tropicalis）的显微镜观察显示，酵母液泡内存在类似细菌的体。液泡的明显空腔表明酵母细胞壁完美地收集了光。透射电子显微镜观察显示，酵母细胞壁具有电子致密的外层和电子透明的内层。从酵母总 DNA 中扩增出了蓝藻特异性 16S rRNA 基因。将酵母在蒸馏水中培养会导致细胞内细菌的切除，这些细菌在蓝藻特异性培养基上生长。对切除细菌的湿片和革兰氏染色制剂的检查显示出典型的珠状须毛。蓝藻特异性基因 16S rRNA、cnfR 和 dxcf 的扩增证实了细菌身份为鞘丝藻属（Leptolyngbya boryana）。这些结果表明，酵母的半透明细胞壁已经通过进化工程化，以接收光，用于蓝藻的生命活动。
