摘要

Extracellular matrix plays a significant role in formation of matrix structure, biogranulation process and improvement of stability of anammox granules. Distributions of cells and extracellular polymeric substances (EPS) in anammox granules cultured from activated sludge and inactive methanogenic granules were probed. Anammox bacteria secreted more EPS than anaerobic/aerobic granules. The layer of EPS surrounding anammox cells was thicker than other types of granules. In high-enriched granules, the proteins and beta-D-glucopyranose polysaccharides were principally distributed at the core, whereas the cells and alpha-D-glucopyranose polysaccharide accumulated in both the interior and outer layers of granules. In low-enriched ones, cells and alpha-D-glucopyranose polysaccharides were mainly distributed at the outer rim and the beta-D-glucopyranose polysaccharides were located in both the core and the outer layer, whilst the proteins were distributed throughout the whole structure of granules. EPS distribution indicated that low-enriched granules possessed higher stability than high-enriched ones, in consistent with granule strength test.