外源和内源呼吸模式下好氧活性污泥的微生物群落演替及生物活性特征

通过模拟好氧活性污泥实验，采用PCR-DGGE技术并监测不同时期的CODCr、脱氢酶和总蛋白质的质量浓度，研究在外源和内源呼吸模式下，微生物群落结构及相关生物活性的变化。结果表明：未添加碳源处理中 CODCr的质量浓度稳定在100 mg·L-1左右；脱氢酶的质量浓度从1μg·mL-1降低到接近0μg·mL-1；总蛋白的质量浓度从0.05 mg·mL-1上升至0.07 mg·mL-1后下降至0.01 mg·mL-1左右；同时，微生物群落结构变化不大。外加葡萄糖处理中CODCr的质量浓度从1000 mg·L-1下降并稳定在100 mg·L-1左右；脱氢酶的质量浓度从2μg·mL-1上升到5μg·mL-1；总蛋白的质量浓度均从0.05 mg·mL-1上升至0.07 mg·mL-1后下降至0.005 mg·mL-1左右；同时，微生物群落多样性呈现收敛趋势。内源和外源呼吸模式下的活性污泥中，变形菌门（ Proteobacteria ）都是绝对优势种群，其次是拟杆菌门（ Bacteroidetes ）。内源呼吸末期δ-变形菌门（Deltaproteobacteria）消失，外源呼吸末期硝化螺菌门（Nitrospirae）消失。

Bacterial community and metabolic characteristics during endogenous and exogenous periods in activated sludge

PCR-DGGE based microbial community analysis combining the determination of the concentration of CODCr, dehydrogenase and total protein was conducted to investigate bacterial community succession and the change of bioactivity in activated sludge fed with or without glucose as carbon resource. Results showed that：in sludge without glucose, bacterial community structure was compariably stable; CODCr concentration was stable at 100 mg·L-1 during the whole incubation of 720 h;dehydrogenase concentration fell to nearly 0 μg·mL-1 from 1 μg·mL-1; amendment with glucose, which raised dehydrogenase concentration to 5μg·mL-1 from 2μg·mL-1, lowered bacterial diversity and caused convergent development on bacterial community structure. Total protein in sludge fed with and without glucose both rose rapidly from 0.05 mg·mL-1 to 0.07 mg·mL-1 at 72 h, then decreased to and kept at 0.01 mg·mL-1 and 0.005 mg·mL-1, respectively. Proteobacteria, following by Bacteroidetes, is the absolutely predominant habitant in sludge under both endogenous and exogenous respiration. Deltaproteobacteria fade away under endogenous respiration over time, while Nitrospirae disappeared under exogenous respiration.