聚糖原菌富集实验及其内源过程探究

细胞衰减是微生物内源过程的一个重要组成部分，可分为由细胞死亡引起的数量衰减和由细胞活性降低引起的活性衰减两部分.通过挥发性脂肪酸（VFA）吸收速率(VFAUR)测定、荧光原位杂交技术（FISH）以及LIVE/DEAD细胞染色技术，研究了富集聚糖原菌（GAOs）在序批式反应器（SBR）系统中好氧环境下的衰减特征.结果表明，当T=30℃、进料中m(COD)∶m(P)=100时，SBR系统中GAOs富集比例达94%.测定和计算表明，SBR富集系统中GAOs衰减速率和死亡速率分别为0.132 d^-1和0.034 d^-1，其数量衰减和活性衰减占其细胞总衰减比例分别为26%和74%.可见，GAOs数量衰减只占其细胞总衰减中很小一部分，而绝大部分衰减由活性衰减所引起.

Enriched Experiment and Endogenous Processes of Glycogen-Accumulating Organisms (GAOs)

Cell decay is an important part of microbiological endogenous processes, which consists of cell death (reduction in the amount of active bacteria) and activity decay (reduction in the specific activity of active bacteria). By means of measuring maximal anaerobic volatile fatty acid (VFA) uptake rates (VFAUR), analyzing 16S rRNA with fluorescence in-situ hybridization (FISH) and observing membrane integrity by live/dead staining, the aerobic decay characteristics of glycogen-accumulating organisms (GAOs) in an enriched GAOs sequencing batch reactor (SBR) system were investigated. It was experimentally identified that a highly enriched culture of GAOs (94%) was obtained by maintaining the temperature at 30 degrees C in the SBR and a high m (COD): m (P) at 100 in the feed. The experimental results and calculations revealed that the decay and death rates of GAOs were 0.132 d(-1) and 0.034 d(-1) respectively, which demonstrated that cell death and activity decay accounted for respective 26% and 74% of the total GAOs cell decay. For this reason, cell death was only a minor factor causing the cell decay of GAOs, and activity decay was mostly responsible for this process.