Bacillus sp. SFC 500-1E, a bacterial strain isolated from tannery sediments, is able to remove Cr(VI) and simultaneously tolerate high concentrations of phenol. In this study, we used high-resolution microscopies, fluorescence polarization techniques, and several biochemical approaches to improve our understanding about the adaptive mechanisms of this strain to survive in the presence of Cr(VI) and phenol, both individually and simultaneously. Among adaptive strategies developed by Bacillus sp. SFC 500-1E, an increase in bacterial size, such as length, width, and height, and ultrastructural alterations, such as electron-dense precipitates, the presence of exopolymers, and cell lysis, are noteworthy. The exopolymers observed were consistent with the extensive biofilm formation and exopolysaccharides and extracellular protein quantification. At the cell membrane level, a rapid rigidity was induced in Cr(VI) + phenol treatment. This effect was counteracted after 16 h by changes at the level of phospholipids, mainly in the composition of fatty acids (FAs); in particular, an increase in the unsaturated fatty acid/saturated fatty acid ratio was detected. This study shows evidence of some adaptive responses displayed by Bacillus sp. SFC 500-1E, which allows it to survive in stressful conditions.

中文翻译：

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芽孢杆菌的形态和结构响应。Cr(VI) 和苯酚处理后的 SFC 500-1E

芽孢杆菌 SFC 500-1E 是一种从制革厂沉积物中分离出来的细菌菌株，能够去除 Cr(VI) 并同时耐受高浓度的苯酚。在这项研究中，我们使用高分辨率显微镜、荧光偏振技术和几种生化方法来提高我们对这种菌株在 Cr(VI) 和苯酚存在下单独和同时生存的适应性机制的理解。在芽孢杆菌开发的适应性策略中。SFC 500-1E、细菌大小的增加（例如长度、宽度和高度）和超微结构改变（例如电子致密沉淀、外聚合物的存在和细胞裂解）是值得注意的。观察到的外聚合物与广泛的生物膜形成、外多糖和细胞外蛋白质定量一致。在细胞膜水平上，在 Cr(VI) + 苯酚处理中诱导了快速刚性。这种影响在 16 小时后被磷脂水平的变化抵消，主要是脂肪酸 (FA) 的组成；特别是，检测到不饱和脂肪酸/饱和脂肪酸比例增加。这项研究显示了芽孢杆菌表现出的一些适应性反应的证据。SFC 500-1E，使其能够在压力条件下生存。