Tsuneda S, Park S, Hayashi H, Jung J, Hirata A
Department of Chemical Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
Water Sci Technol. 2001;43(6):197-204.
The possibility of enhancing nitrifying biofilm formation rate with the aid of selected EPS produced by heterotrophic bacteria was investigated. When EPS production characteristics were examined for four kinds of heterotrophs isolated from a domestic wastewater treatment reactor, two strains obtained from biofilms (B1, B2) exhibited a higher polysaccharide production rate than those from suspended flocs (A1, A2). Among EPS components, the concentration of uronic acids gave a good correlation with flocculation ability, which suggests that acidic polysaccharides play a major role in bioaggregate formation. Addition of 1 g/L D-glucuronic acid as an EPS substitute enhanced the homocoagulation rate of autotrophic Nitrosomonas europaea and altered its zeta potential from ñ30.4 mV to +4.3 mV, which indicates a possibility that particular EPS components produced by heterotrophs are utilized as neutralising reagents for nitrifying biofilm formation. Moreover, when heterotrophic isolates with Nitrobacter winogradskyi were cultured in batch with fabric supports, biofilm formed on the substratum. These experimental results suggest the application of selected EPS for enhancing nitrifying biofilm formation.
研究了借助异养细菌产生的特定胞外聚合物（EPS）提高硝化生物膜形成速率的可能性。当检测从生活污水处理反应器中分离出的四种异养菌的EPS产生特性时，从生物膜中获得的两株菌株（B1、B2）的多糖产生率高于从悬浮絮体中获得的菌株（A1、A2）。在EPS成分中，糖醛酸的浓度与絮凝能力具有良好的相关性，这表明酸性多糖在生物聚集体形成中起主要作用。添加1 g/L D-葡萄糖醛酸作为EPS替代物可提高自养型欧洲亚硝化单胞菌的同凝速率，并将其ζ电位从−30.4 mV改变为+4.3 mV，这表明异养菌产生的特定EPS成分有可能被用作硝化生物膜形成的中和剂。此外，当将异养分离株与维诺格拉德斯基硝化杆菌在有织物载体的分批培养中培养时，在基质上形成了生物膜。这些实验结果表明可应用特定的EPS来提高硝化生物膜的形成。
