Self-aggregation Property of Bacterial Alginates Extracted from Aerobic Granules
好氧颗粒污泥藻酸盐提取物的聚集形态研究

To explore bacterial alginates role in aerobic granules' formation, the alginate was extracted from aerobic granules and identified. Its aggregation property in 50mg·L-1CaCl2 solution was investigated by the atomic force microscopy (AFM). Bacterial alginates amounted to 35.1%±1.9% of granules' dry mass. With the concentration increased from 10 mg·L-1 to 500 mg·L-1 in 50mg·L-1 CaCl2, the extracted alginates tended to form ordered aggregations, with the shape changed from randomly distributed globules, to rod-like and flower-shaped aggregations, and finally to weblike networks due to their supramolecular self-assembly property. The three dimensional alginate-metal gel is the structural polymer of aerobic granules, and the alginates-Ca2+gel formation plays an important role in granules' formation and structure stabilization.