Initial Assemblage of Bacterial Saccharic Fibrils and Element Deposition to Form an Immature Sheath in Cultured Leptothrix sp Strain OUMS1
Initial Assemblage of Bacterial Saccharic Fibrils and Element Deposition to Form an Immature Sheath in Cultured Leptothrix sp Strain OUMS1
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DOI：
10.3390/min1010157
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发表时间：
2011-12-01
期刊：
影响因子：
2.5
通讯作者：
Takada, Jun
中科院分区：
文献类型：
--
作者：
Furutani, Mitsuaki;Suzuki, Tomoko;Takada, Jun
在水生环境中，纤发菌属产生由细菌外聚合物和水相无机元素的复杂混合物组成的细胞外Fe或Mn结壳的管状鞘。本超微结构研究调查初始组装的细菌糖原纤维和随后的沉积的水相无机元素，形成未成熟的鞘骨架培养的Leptothrix sp.菌株OUMS 1。培养一天后，在细菌细胞包膜的表面上观察到球状和/或线状分泌物，并且分泌体被运输穿过间隔空间远离细胞以形成包含组装和混合的原纤维的未成熟鞘骨架。能量色散X射线微量分析和特定的Bi染色检测到可区分的水平的P，微量Si，和显着量的碳水化合物的骨架，但不是Fe。到第二天，骨架明显增厚，内层几乎平行排列的原纤维，沿着具有低水平的Fe沉积，而外部混杂的纤维层表现出Fe沿着的重沉积，P和Si的显著沉积。这些结果表明，基本的鞘建设进行两个步骤，在培养条件下：最初的组合细菌糖原纤维起源于细胞的包膜和随后的沉积水相铁，磷，和硅。
In an aquatic environment, the genus Leptothrix produces an extracellular Fe- or Mn-encrusted tubular sheath composed of a complex hybrid of bacterial exopolymers and aqueous-phase inorganic elements. This ultrastructural study investigated initial assemblage of bacterial saccharic fibrils and subsequent deposition of aqueous-phase inorganic elements to form the immature sheath skeleton of cultured Leptothrix sp. strain OUMS1. After one day of culture, a globular and/or thread-like secretion was observed on the surface of the bacterial cell envelope, and secreted bodies were transported across the intervening space away from the cell to form an immature sheath skeleton comprising assembled and intermingled fibrils. Energy dispersive X-ray microanalysis and specific Bi-staining detected a distinguishable level of P, trace Si, and a notable amount of carbohydrates in the skeleton, but not Fe. By the second day, the skeleton was prominently thickened with an inner layer of almost parallel aligned fibrils, along with low level of Fe deposition, whereas an outer intermingled fibrous layer exhibited heavy deposition of Fe along with significant deposition of P and Si. These results indicate that basic sheath-construction proceeds in two steps under culture conditions: an initial assemblage of bacterial saccharic fibrils originated from the cell envelope and the subsequent deposition of aqueous-phase Fe, P, and Si.