Matheson A, Yang M K, Smith R P
J Bacteriol. 1973 Jul;115(1):349-57. doi: 10.1128/jb.115.1.349-357.1973.
The physiological differences between Bacillus subtilis (ATCC 6633) cells derived from a glucose-salts-yeast extract (GSY) medium and those of cells from tryptose broth permitted the identification of variables in protoplasting environments which noticeably affected the clarity of mesosomal ribosomes. They were the sucrose and magnesium ion concentrations and the type of buffer used. The environment suitable for conversion of GSY cells to the protoplast state was a 0.02 M tris(hydroxymethyl)aminomethane-hydrochloride buffer, pH 7.2, containing 0.6 M sucrose and 0.03 M MgCl(2). Branched mesosomal tubules and a unique organization of vesicles were detected in thin sections and in negative stains of the specimens. Ribosomes were demonstrable in the extruded structures associated with protoplasts that had been prepared according to four fixation schedules and embedded in either of two epoxy plastics. Adjustments in the fixation schedules improved the clarity of the large bodies of protoplast cytoplasm to a degree equivalent to that of their dangling appendages.
源自葡萄糖 - 盐 - 酵母提取物（GSY）培养基的枯草芽孢杆菌（ATCC 6633）细胞与胰蛋白胨肉汤培养基中的细胞在生理上存在差异，这使得能够确定原生质体形成环境中的变量，这些变量显著影响了中体核糖体的清晰度。这些变量包括蔗糖和镁离子浓度以及所用缓冲液的类型。适合将GSY细胞转化为原生质体状态的环境是含有0.6 M蔗糖和0.03 M MgCl₂的0.02 M三（羟甲基）氨基甲烷 - 盐酸盐缓冲液，pH 7.2。在标本的超薄切片和负染中检测到分支状的中体小管和独特的囊泡组织。在按照四种固定程序制备并包埋在两种环氧塑料中的任何一种中的原生质体相关的挤出结构中，核糖体是可证实的。固定程序的调整将原生质体细胞质大体的清晰度提高到与其悬垂附属物相当的程度。
