Tsai Y P, Pai T Y, Qiu J M
Department of Civil Engineering, National Chi Nan University, 1, University Rd., PuLi, Nantou 545, Taiwan.
J Biotechnol. 2004 Jul 15;111(2):155-67. doi: 10.1016/j.jbiotec.2004.04.005.
The logistic growth model was applied in the study to evaluate the impacts of assimilable organic carbon (AOC) concentration on the growth characteristics of biofilm and bulk bacteria under high flow velocity condition. The experimental results showed that there existed a growth and decline relation between biofilm and bulk bacteria at the low (0.05 mg/L) and medium (0.5 mg/L) AOC levels. Increasing the AOC concentration up to 1.0 mg/L, it resulted in high amounts of biofilm and bulk bacteria simultaneously. Although the carrying capacity of biofilm bacteria at the medium condition of AOC level was substantially reduced, the specific growth rate (GR) of biofilm bacteria was largest at this condition. It showed that the reduction of biofilm bacteria quantity did not represent the suppression of bacterial growth. The quantity of bulk water bacteria was obviously dependent with the quantity of biofilm bacteria and the increase of free bacteria with time in networks was mainly due to the growth and detachment of biofilm bacteria, not due to the growth of free bacteria themselves. The maximum growth rate of biofilm bacteria was increased upon increasing the AOC level. It indicated that the AOC level was an important factor affecting the growth of biofilm bacteria.
本研究应用逻辑斯蒂增长模型，评估了在高流速条件下，可同化有机碳（AOC）浓度对生物膜和水体细菌生长特性的影响。实验结果表明，在低（0.05 mg/L）和中（0.5 mg/L）AOC水平下，生物膜和水体细菌之间存在生长与衰退的关系。将AOC浓度提高到1.0 mg/L时，会同时导致大量生物膜和水体细菌的出现。尽管在AOC水平为中等条件下生物膜细菌的承载能力大幅降低，但此时生物膜细菌的比生长速率（GR）最大。这表明生物膜细菌数量的减少并不代表细菌生长受到抑制。水体细菌数量明显依赖于生物膜细菌数量，且随着时间推移网络中游离细菌的增加主要是由于生物膜细菌的生长和脱落，而非游离细菌自身的生长。随着AOC水平的提高，生物膜细菌的最大生长速率增加。这表明AOC水平是影响生物膜细菌生长的一个重要因素。
