A mathematical description of the behaviour of mixed chemostat cultures of an autotrophic nitrifier and a heterotrophic nitrifier/aerobic denitrifier; a comparison with experimental data

VANNIEL, E; ROBERTSON, L; KUENEN, J

doi:10.1016/0378-1097(93)90005-m

Cited by 8 publications

(5 citation statements)

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“…In pure culture, N. europaea exhibits K m (O 2 ) values between 6.9 and 17.4 M. Oxygen concentration measurements on the rice root surface were generally higher than these values (Fig. 5), but in the case of Mahsuri, oxygen could become more limiting in the presence of heterotrophic bacteria, which are generally superior competitors for oxygen compared to AOB (38,54). We have observed large, active, and presumably heterotrophic bacteria on root biofilms derived from Mahsuri (Fig.…”

Section: Resultsmentioning

confidence: 95%

Influence of Different Cultivars on Populations of Ammonia-Oxidizing Bacteria in the Root Environment of Rice

Briones

Okabe

Umemiya

et al. 2002

Appl Environ Microbiol

152

102

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Comparisons of the activities and diversities of ammonia-oxidizing bacteria (AOB) in the root environment of different cultivars of rice (Oryza sativa L.) indicated marked differences despite identical environmental conditions during growth. Gross nitrification rates obtained by the 15 N dilution technique were significantly higher in a modern variety, IR63087-1-17, than in two traditional varieties. Phylogenetic analysis based on the ammonium monooxygenase gene (amoA) identified strains related to Nitrosospira multiformis and Nitrosomonas europaea as the predominant AOB in our experimental rice system. A method was developed to determine the abundance of AOB on root biofilm samples using fluorescently tagged oligonucleotide probes targeting 16S rRNA. The levels of abundance detected suggested an enrichment of AOB on rice roots. We identified 40 to 69% of AOB on roots of IR63087-1-17 as Nitrosomonas spp., while this subpopulation constituted 7 to 23% of AOB on roots of the other cultivars. These results were generally supported by denaturing gradient gel electrophoresis of the amoA gene and analysis of libraries of cloned amoA. In hydroponic culture, oxygen concentration profiles around secondary roots differed significantly among the tested rice varieties, of which IR63087-1-17 showed maximum leakage of oxygen. The results suggest that varietal differences in the composition and activity of root-associated AOB populations may result from microscale differences in O 2 availability.

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Section: Resultsmentioning

confidence: 95%

Influence of Different Cultivars on Populations of Ammonia-Oxidizing Bacteria in the Root Environment of Rice

Briones

Okabe

Umemiya

et al. 2002

Appl Environ Microbiol

152

102

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“…The delayed onset of nitrification after the start of the aeration and the accumulation of nitrite despite the high abundance of NOB very likely reflect the limited supply of oxygen. Due to their high K m for oxygen, AOB and NOB are poor competitors compared to heterotrophic bacteria (17,41,56). Thus, during the initial aeration period, oxygen is taken up preferentially by heterotrophs as the PAO.…”

Section: Discussionmentioning

confidence: 99%

“…Nitrifying bacteria (i.e., ammonia-oxidizing bacteria [AOB] and nitrite-oxidizing bacteria [NOB]) usually show low maximum growth rates, relatively low substrate affinities, and high sensitivity to toxic shocks or sudden pH changes (17,25,41). In the presence of organic matter, they can be easily outcompeted by heterotrophs for oxygen (56) and ammonia (19). Other problems to be solved are the inhibition of denitrification by the presence of oxygen (5) and the need for cyclic changes of oxic and anoxic (i.e., free of oxygen and nitrate) conditions for biological phosphate removal (34).…”

mentioning

confidence: 99%

Community Structure and Activity Dynamics of Nitrifying Bacteria in a Phosphate-Removing Biofilm

Gieseke

Purkhold²,

Wagner³

et al. 2001

Appl Environ Microbiol

290

179

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The microbial community structure and activity dynamics of a phosphate-removing biofilm from a sequencing batch biofilm reactor were investigated with special focus on the nitrifying community. O 2 , NO 2 ؊ , and NO 3 ؊ profiles in the biofilm were measured with microsensors at various times during the nonaerated-aerated reactor cycle. In the aeration period, nitrification was oxygen limited and restricted to the first 200 m at the biofilm surface. Additionally, a delayed onset of nitrification after the start of the aeration was observed. Nitrate accumulating in the biofilm in this period was denitrified during the nonaeration period of the next reactor cycle. Fluorescence in situ hybridization (FISH) revealed three distinct ammonia-oxidizing populations, related to the Nitrosomonas europaea, Nitrosomonas oligotropha, and Nitrosomonas communis lineages. This was confirmed by analysis of the genes coding for 16S rRNA and for ammonia monooxygenase (amoA). Based upon these results, a new 16S rRNA-targeted oligonucleotide probe specific for the Nitrosomonas oligotropha lineage was designed. FISH analysis revealed that the first 100 m at the biofilm surface was dominated by members of the N. europaea and the N. oligotropha lineages, with a minor fraction related to N. communis. In deeper biofilm layers, exclusively members of the N. oligotropha lineage were found. This separation in space and a potential separation of activities in time are suggested as mechanisms that allow coexistence of the different ammonia-oxidizing populations. Nitrite-oxidizing bacteria belonged exclusively to the genus Nitrospira and could be assigned to a 16S rRNA sequence cluster also found in other sequencing batch systems.Modern biological treatment of wastewater involves not only C removal, but also elimination of the nutrients P and N (5,20). This requires the combined or sequential actions of various groups of microorganisms, such as heterotrophic bacteria, phosphate-accumulating organisms (PAO), and nitrifying and denitrifying bacteria. Consequently, purification plants and processes have become increasingly complex to satisfy the needs of the different microorganisms, usually in several reactor stages (5, 27). The integration of different functions in a single reactor would save reaction space and time and therefore is desirable from an economical point of view. However, difficulties often arise in establishing stable nitrification in such complex systems. Nitrifying bacteria (i.e., ammonia-oxidizing bacteria [AOB] and nitrite-oxidizing bacteria [NOB]) usually show low maximum growth rates, relatively low substrate affinities, and high sensitivity to toxic shocks or sudden pH changes (17,25,41). In the presence of organic matter, they can be easily outcompeted by heterotrophs for oxygen (56) and ammonia (19). Other problems to be solved are the inhibition of denitrification by the presence of oxygen (5) and the need for cyclic changes of oxic and anoxic (i.e., free of oxygen and nitrate) conditions for biological phosphate removal...

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“…In addition, nitrification was supposed to be affected by organic matter loading rate due to competition for oxygen between heterotrophic and nitrifying bacteria (van Niel et al, 1993;Dalhammar et al, 1999;Truu et al, 2005;Fountoulakis et al, 2009). As stated by Caselles-Osorio (2006), the oxygen in the wetland bed was not adequate for nitrification even at low-to-moderate organic loading rates (4-12 g COD m −2 d −1 ).…”

Section: Evaluations Of Treatment Performance and Factors Influencingmentioning

confidence: 99%

Treatment performance of integrated vertical-flow constructed wetland plots for domestic wastewater

Chang

Dai

et al. 2012

Ecological Engineering

126

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A mathematical description of the behaviour of mixed chemostat cultures of an autotrophic nitrifier and a heterotrophic nitrifier/aerobic denitrifier; a comparison with experimental data

Abstract: A mathematical description of the behaviour of mixed chemostat cultures of an autotrophic nitrifier and a heterotrophic nitrifier/aerobic denitrifier; a comparison with experimental data van Niel, Ed; Robertson, L.A.; Kuenen, J.G.

Cited by 8 publications

References 0 publications

Influence of Different Cultivars on Populations of Ammonia-Oxidizing Bacteria in the Root Environment of Rice

Influence of Different Cultivars on Populations of Ammonia-Oxidizing Bacteria in the Root Environment of Rice

Community Structure and Activity Dynamics of Nitrifying Bacteria in a Phosphate-Removing Biofilm

Treatment performance of integrated vertical-flow constructed wetland plots for domestic wastewater

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