School of Chemical Engineering, University of New South Wales (UNSW), Sydney, 2052, Australia.
School of Civil and Environmental Engineering, University of New South Wales (UNSW), Sydney, 2052, Australia.
Appl Microbiol Biotechnol. 2024 May 6;108(1):321. doi: 10.1007/s00253-024-13162-x.
Most reduced organic matter entering activated sludge systems is particulate (1-100-µm diameter) or colloidal (0.001-1-µm diameter), yet little is known about colonization of particulate organic matter by activated sludge bacteria. In this study, colonization of biopolymers (chitin, keratin, lignocellulose, lignin, and cellulose) by activated sludge bacteria was compared with colonization of glass beads in the presence and absence of regular nutrient amendment (acetate and ammonia). Scanning electron microscopy and quantitative PCR revealed chitin and cellulose were most readily colonized followed by lignin and lignocellulose, while keratin and glass beads were relatively resistant to colonization. Bacterial community profiles on particles compared to sludge confirmed that specific bacterial phylotypes preferentially colonize different biopolymers. Nitrifying bacteria proved adept at colonizing particles, achieving higher relative abundance on particles compared to bulk sludge. Denitrifying bacteria showed similar or lower relative abundance on particles compared to sludge. KEY POINTS: • Some activated sludge bacteria colonize natural biopolymers more readily than others. • Nitrifying bacteria are overrepresented in natural biopolymer biofilm communities. • Biopolymers in wastewater likely influence activated sludge community composition.
大多数进入活性污泥系统的有机物质是颗粒状的（直径 1-100μm）或胶体状的（直径 0.001-1μm），但对于活性污泥细菌对颗粒有机物质的定殖知之甚少。在这项研究中，比较了活性污泥细菌对生物聚合物（几丁质、角蛋白、木质纤维素、木质素和纤维素）的定殖与玻璃珠在有规律的营养物添加（乙酸盐和氨）和没有营养物添加情况下的定殖。扫描电子显微镜和定量 PCR 显示，几丁质和纤维素最容易被定殖，其次是木质素和木质纤维素，而角蛋白和玻璃珠则相对难以定殖。与污泥相比，颗粒上的细菌群落图谱证实了特定的细菌类群更倾向于定殖不同的生物聚合物。硝化细菌在定殖颗粒方面表现出色，与活性污泥相比，它们在颗粒上的相对丰度更高。与污泥相比，反硝化细菌在颗粒上的相对丰度相似或更低。要点：
一些活性污泥细菌比其他细菌更容易定殖天然生物聚合物。
硝化细菌在天然生物聚合物生物膜群落中过度表达。
废水中的生物聚合物可能会影响活性污泥群落组成。
