Microbial ecology of nitrifying bacteria in wastewater treatment process examined by fluorescence in situ hybridization

Aoi, Yoshiteru; Miyoshi, Tomoko; Okamoto, T.; Tsuneda, Satoshi; Hirata, Akira; Kitayama, Atsushi; Nagamune, Teruyuki

doi:10.1016/s1389-1723(00)80075-4

Cited by 50 publications

(9 citation statements)

References 18 publications

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“…After rapid freezing at −20°C, 20 μm thick slices through the middle of the granule were prepared with a cryostat (CM1850, Leica, Heidelberg, Germany) and placed on a gelatin‐coated slide (Matsunami, Osaka, Japan). After air drying overnight, the slices were dehydrated by successive passage through 50%, 80% and 98% ethanol washes (for 3 min each), air‐dried and stored at room temperature (Aoi et al. , 2000).…”

Section: Methodsmentioning

confidence: 99%

Microbial community structure in autotrophic nitrifying granules characterized by experimental and simulation analyses

Matsumoto

Katoku

Saeki

et al. 2009

Environmental Microbiology

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108

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This study evaluates the community structure in nitrifying granules (average diameter of 1600 mum) produced in an aerobic reactor fed with ammonia as the sole energy source by a multivalent approach combining molecular techniques, microelectrode measurements and mathematical modelling. Fluorescence in situ hybridization revealed that ammonia-oxidizing bacteria dominated within the first 200 mum below the granule surface, nitrite-oxidizing bacteria a deeper layer between 200 and 300 mum, while heterotrophic bacteria were present in the core of the nitrifying granule. Presence of these groups also became evident from a 16S rRNA clone library. Microprofiles of NH(4)(+), NO(2)(-), NO(3)(-) and O(2) concentrations measured with microelectrodes showed good agreement with the spatial organization of nitrifying bacteria. One- and two-dimensional numerical biofilm models were constructed to explain the observed granule development as a result of the multiple bacteria-substrate interactions. The interaction between nitrifying and heterotrophic bacteria was evaluated by assuming three types of heterotrophic bacterial growth on soluble microbial products from nitrifying bacteria. The models described well the bacterial distribution obtained by fluorescence in situ hybridization analysis, as well as the measured oxygen, nitrite, nitrate and ammonium concentration profiles. Results of this study are important because they show that a combination of simulation and experimental techniques can better explain the interaction between nitrifying bacteria and heterotrophic bacteria in the granules than individual approaches alone.

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Section: Methodsmentioning

confidence: 99%

Microbial community structure in autotrophic nitrifying granules characterized by experimental and simulation analyses

Matsumoto

Katoku

Saeki

et al. 2009

Environmental Microbiology

Self Cite

108

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“…Two distinct groups of strict aerobic proteobacteria contribute to nitrification (Aoi et al 2000). First, ammonia nitrogen is oxidized to nitrite by AOB, by species like Nitrosococcus, Nitrosospira and Nitrosomonas (Koops & Pommerening-R€ oser 2001).…”

Section: Autotrophic Bacteriamentioning

confidence: 99%

Microorganisms in recirculating aquaculture systems and their management

Rurangwa¹,

Verdegem

2014

Reviews in Aquaculture

197

150

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Recirculation aquaculture systems (RASs) are increasingly considered as production systems of the future with a minimum ecological impact for the production of aquatic food. To maintain a good water quality and to produce quality and healthy fishery products, the systems depend on a diverse microbial community involved in different processes of water purification but also in unwanted effects. The article reviews the present knowledge on microorganisms in RAS, their relative distribution within the system compartments and their role in system performance. The system possesses different microniches in which microorganisms retrieve their preferential conditions for oxygen and nutrients. Ammonia and nitrite are oxidized under aerobic conditions into less toxic compounds. Anaerobic ammonium oxidizers in the biofilm oxidize anaerobically both ammonia and nitrites into less harmful dinitrogen gas. Heterotrophic bacteria mineralize organic matter derived from uneaten feeds, dead bodies and excreta of fish. Under conditions of high organic load and high C/N content, nitrifiers are overgrown by heterotrophs with negative effects to the nitrification process. For not yet understood reasons, the presence of off‐flavour‐producing microorganisms occurs also in RAS. Microbial management and management of inputs to the systems to prevent the proliferation of pathogens are discussed and possible management techniques of off‐flavours are also presented. Research orientations are given to explore further the potential of heterotrophic bacteria in microbial management and intensive aquaculture production in systems other than RAS.

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“…After the microelectrode measurement, a part of the biofilm was sampled and immediately fixed with freshly prepared 4% paraformaldehyde solution for 18 h at 4 8C. The sample was embedded in OCT compound (Tissu-Tek, Sakura Finetek, Tokyo, Japan) overnight to infiltrate the OCT compound into the biofilm, as described by Aoi et al (2000). After rapid freezing at 2 21 8C, 20 mm thick vertical slices were prepared with a cryostat (CM1850, Leica, Heidelderg, Germany) and placed on a gelatin-coated slide (Matsunami, Osaka, Japan).…”

Section: Fixation and Cryosectioning Of Biofilm Samplesmentioning

confidence: 99%

Experimental and simulation analysis of community structure of nitrifying bacteria in a membrane-aerated biofilm

Matsumoto

Terada

Aoi

et al. 2007

Water Science and Technology

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Until now, only few attempts have been made to assess biofilm models simulating microenvironments in a biofilm. As a first step, we compare the microenvironment observed in a membrane aerated biofilm (MAB) to that derived from a two-dimensional computational model with individual ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) embedded in a continuum EPS matrix. Gradients of oxygen were determined by means of microelectrodes. The change in nitrifying bacterial populations with the biofilm depth was quantified using fluorescence in situ hybridization (FISH) in combination with a confocal laser scanning microscopy (CLSM). Microelectrode measurements revealed that oxic and anoxic or anaerobic regions exist within the MAB. The oxygen profile predicted by the model showed good agreement with that obtained by microelectrode measurements. The oxic part of the biofilm was dominated by NSO190 probe-hybridized AOB, which formed relatively large clusters of cells directly on the membrane surface, and by the NOB belonging to genus Nitrobacter sp. On the other hand, NOB belonging to genus Nitrospira sp. were abundant at the oxic-anoxic interface. The model prediction regarding AOB and Nitrobacter sp. distribution was consistent with the experimental counterpart. Measurements of AOB cluster size distribution showed that colonies are slightly larger adjacent to the membrane than at the inner part of the biofilm. The sizes predicted by the current model are larger than those obtained in the experiment, leading to the arguments that some factors not contained in the model would affect the cluster size.

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Microbial ecology of nitrifying bacteria in wastewater treatment process examined by fluorescence in situ hybridization

Cited by 50 publications

References 18 publications

Microbial community structure in autotrophic nitrifying granules characterized by experimental and simulation analyses

Microbial community structure in autotrophic nitrifying granules characterized by experimental and simulation analyses

Microorganisms in recirculating aquaculture systems and their management

Experimental and simulation analysis of community structure of nitrifying bacteria in a membrane-aerated biofilm

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