Chen M Y, Lee D J, Tay J H
Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan.
Appl Microbiol Biotechnol. 2007 Jan;73(6):1463-9. doi: 10.1007/s00253-006-0617-x. Epub 2006 Oct 7.
Extracellular matrix provides an architectural structure and mechanical stability for aerobic granules. Distributions of cells and extracellular polymeric substances (EPS), including proteins, alpha- and beta-D-glucopyranose polysaccharides, in acetate-fed granules and phenol-fed granules were probed using a novel quadruple staining scheme. In acetate-fed granules, protein and beta-D-glucopyranose polysaccharides formed the core, whereas, the cells and alpha-D-glucopyranose polysaccharides accumulated in the granule outer layers. Based on these experimental findings, this study indicated that different conclusions can be obtained regarding EPS distributions when granules were stained differently. The core of phenol-fed granules, conversely, was formed principally by proteins; whereas, the cells and alpha- and beta-D-glucopyranose polysaccharides were accumulated at an outer filamentous layer. Using a series of confocal laser scanning microscope (CLSM) images whose threshold values were determined via Otsu's scheme, the three-dimensional distributions of cells and EPS were produced using a polygonal surface model. Structural information extracted can be applied in further development of comprehensive granule models.
细胞外基质为好氧颗粒提供了一种建筑结构和机械稳定性。使用一种新颖的四重染色方案，探究了乙酸盐喂养颗粒和苯酚喂养颗粒中细胞和细胞外聚合物（EPS）的分布情况，其中EPS包括蛋白质、α-和β-D-吡喃葡萄糖多糖。在乙酸盐喂养颗粒中，蛋白质和β-D-吡喃葡萄糖多糖形成核心，而细胞和α-D-吡喃葡萄糖多糖则聚集在颗粒外层。基于这些实验结果，本研究表明，当颗粒采用不同染色方法时，关于EPS分布会得出不同结论。相反，苯酚喂养颗粒的核心主要由蛋白质形成；而细胞以及α-和β-D-吡喃葡萄糖多糖则聚集在外部丝状层。利用一系列通过大津法确定阈值的共聚焦激光扫描显微镜（CLSM）图像，使用多边形表面模型生成了细胞和EPS的三维分布。提取的结构信息可应用于综合颗粒模型的进一步开发。
