【摘要】 目的观察黑素化培养的马尔尼菲青霉(PM)酵母细胞显微结构的特点,探索PM酵母相黑色素在细胞内的分布情况和合成途径。方法将马尔尼菲青霉标准株FRR分别在含和不含1.0mmol/L左旋多巴(L-DOPA)的基础培养液37℃震荡培养15d,通过光学显微镜和电镜比较有或无L-DOPA干预下酵母相孢子形态学的差异。结果添加L-DOPA的菌株进行培养的培养液颜色变成棕黑色,而不含LDOPA的菌株其培养液不变色。光学显微镜和扫描电镜观察两者形态无明显差异。透射电镜下观察,加入L-DOPA培养的酵母细胞壁内侧面有较多串珠状分布的直径约100nm电子致密颗粒;微体囊腔显著扩大,微体囊腔内电子致密物显著增多。无L-DOPA培养的酵母细胞未见上述现象。结论马尔尼菲青霉酵母相黑色素颗粒主要分布在细胞壁内侧,微体可能为黑色素合成的细胞器。更多还原

【Abstract】 Objective To explore distribution and biosynthetic pathway of melanin in the yeast cells of P. marneffei. Methods P. marneffei strain FRR was grown on a chemically defined liquid medium supplemented with or without 1. 0 mmol / L L-3,4-dihydroxyphenylalanine( L-DOPA) for 15 days at 37℃ in a rotary shaker. The morphology of the yeast cells were observed by optical microscopy and electro microscopy. Results The liquid medium color of the tested strains supplemented with L-DOPA was brown black,while those without LDOPA kept the basic coloration. Yeast cells grown with and without L-DOPA had no difference observed by optical microscopy and scanning electron microscopy. The electron-dense particles with the average diameter of 100nm beaded arrangement at the inner cell wall were observed by transmission electron microscopy on the yeast cells supplemented with L-DOPA,and the vesicle of microbodies expanded with electron-dense material increased significantly. The phenomenon could not be seen on the yeast cells cultured without L-DOPA. Conclusion The melanin particles are mainly arranged at the inner cell wall in yeast form of P. marneffei,and the organelles of microbodies may be responsible for melanin synthesis.更多还原