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Fluorescent antibody technique by the monoclonal antibody method is very useful and helpful for the rapid quantification and in situ detection of the specific bacteria like nitrifiers in a mixed baxterial habitat such as a biofilm. In this study, twelve monoclonal antibodiesagainst Nitrosomonas europaea (IFO14298) and sixteen against Nitrobacter winogradskyi (IFO14297) were raised from splenocytes of mice (BALB/c). It was found that these antibodies exhibited little cross reactivity against various kinds of heterotrophic bacteria. The direct cell count method using monoclonal antibodies could exactly detect and rapidly quantify N. europaea and N. winogradskyi. Moreover, the distribution of N. europaea and N. winogradskyi in a biofilm could be examined by in situ fluorescent antibody technique. It was shown that most of N. winogradskyi existed near the surface part and most of N. europaea existed at the inner part of the polyethylene glycol (PEG) gel pellet, which had entrapped activated sludge and used in a landfill leachate treatment reactor. It was suggested that this monoclonal antibody method was utilized for estimating and controlling the population of nitrifying bacteria as a quick and favorable tool. [ABSTRACT FROM AUTHOR]

Scale-up microcosm system consisting of producer, decomposer and predator was employed to assess effect of LAS on aquatic ecosystem. Effect of LAS was determined with not only population density but also chemical data such as ATP, nutrients, pH and DO, etc. Microorganisms such as bacteria, algae, protozoa and micrometazoa in the microcosm system proliferated and reached to stationary phase on day 16. In the stationary phase, values of biological and chemical factors were constant, supporting the dynamic equilibrium of scale-up microcosm. No observed effect concentration (NOEC) of LAS on population density was less than 1.5 mg-l-1. NOECs of LAS on ATP, DO and P/R (net photosynthesis/respiration) ratio were less than 2.5 mg l-1.It was suggested that scale-up microcosm system was useful for environmental assessment because it could provide precise assessment of chemical substances based on biological and chemical condition of ecosystem. (c) 1997 IAWQ. Published by Elsevier Science Ltd. [ABSTRACT FROM AUTHOR]

Enzyme-linked immunosorbent assay (ELISA) by use of monoclonal antibodies (MAbs) is very useful and helpful for the detection and quantification of the specific bacteria like nitrifiers in a mixed bacterialhabitat. In this study, seven monoclonal antibodies were raised fromsplenocytes of mice (BALB/c) that are specific for the surface antigen of the two kinds of nitrifying bacteria. Three were directed against Nitrosomonas europaea (IFO 14298) and four were directed against Nitrobacter winogradskyi (IFO 1429 7). Cross-reactivities of MAbs against other strains of nitrifying bacteria as well as some kinds of representative heterotrophic bacteria in activated sludge and biofilm were checked to determine die usefulness of MAbs. It was found that there were some strain specificities between the same genera of IFO and ATCC strain. By means of a competitive ELISA, correlation curves for quantifying nitrifying bacteria were developed in a pure culture. It was found that this monoclonal antibody method could be used as a quick and powerful tool for estimating and controlling the population ofnitrifying bacteria. (c) 1997 IAWQ. Published by Elsevier Science Ltd. [ABSTRACT FROM AUTHOR]