Nitrification as a source of soluble organic substrate in biological treatment

1994 ◽  
Vol 30 (6) ◽  
pp. 1-8 ◽  
Author(s):  
Bruce E. Rittmann ◽  
John M. Regan ◽  
David A. Stahl
Keyword(s):  
Kinetic Analysis ◽  
Organic Compounds ◽  
Biological Treatment ◽  
Heterotrophic Bacteria ◽  
Theoretical Work ◽  
Organic Substrate ◽  
Nitrifying Bacteria ◽  
Organic Substrates ◽  
Soluble Microbial Products ◽  
Microbial Products

In complex, multispecies populations, exchange of substrates can be an important beneficial interaction. Prior experimental and theoretical work has led to the hypothesis that the formation of soluble microbial products (SMP) by nitrifying bacteria can provide a supplementary organic substrate for heterotrophic bacteria, thereby augmenting their accumulation and stability, especially when inputs of organic substrates are low. In this study, chemostat experiments carried out with a NO2−-oxidizing strain (Nitrobacter sp.) and an NH4+-oxidizing strain (Nitrosomonas europaea) demonstrated that both nitrifiers produce SMP that can support heterotrophic bacteria. The first evidence was the presence of significant concentrations of soluble COD in the chemostat effluent, even though the influent was free of organic compounds. Second, a small heterotrophic population was maintained, apparently through utilization of the nitrifier-produced SMP. A preliminary kinetic analysis suggested that SMP kinetic parameters can be adapted from parameters measured for heterotrophs.

scholarly journals Substrate-dependent CO2 fixation in heterotrophic bacteria revealed by stable isotope labelling

2020 ◽  
Vol 96 (6) ◽  
Author(s):  
Marina Spona-Friedl ◽  
Alexander Braun ◽  
Claudia Huber ◽  
Wolfgang Eisenreich ◽  
Christian Griebler ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Heterotrophic Bacteria ◽  
Tricarboxylic Acid Cycle ◽  
Carbon Sources ◽  
Organic Substrate ◽  
Gas Chromatography Mass Spectrometry ◽  
Logarithmic Phase ◽  
Natural Environments ◽  
Organic Substrates ◽  
Stable Isotope Labelling

ABSTRACT Virtually all heterotrophs incorporate carbon dioxide by anaplerotic fixation. Little explored, however, is the interdependency of pathways and rates of CO2fixation on the concurrent usage of organic substrate(s). Potentially, this could reveal which substrates out of a pool of dissolved organic carbon are utilised by environmental microorganisms. To explore this possibility, Bacillus subtilis W23 was grown in a minimal medium with normalised amounts of either glucose, lactate or malate as only organic substrates, each together with 1 g/L NaH13CO3. Incorporation of H13CO3− was traced by elemental analysis-isotope ratio mass spectrometry of biomass and gas chromatography-mass spectrometry of protein-derived amino acids. Until the late logarithmic phase, 13C incorporation into the tricarboxylic acid cycle increased with time and occurred via [4–13C]oxaloacetate formed by carboxylation of pyruvate. The levels of 13C incorporation were highest for growth on glucose and lowest on malate. Incorporation of 13C into gluconeogenesis products was mainly detected in the lactate and malate experiment, whereas glucose down-regulated this path. A proof-of-principle study with a natural groundwater community confirmed the ability to determine incorporation from H13CO3− by natural communities leading to specific labelling patterns. This underlines the potential of the labelling approach to characterise carbon sources of heterotrophic microorganisms in their natural environments.

Growth of two serotypes of Nitrobacter in mixotrophic and chemoorganotrophic conditions

1983 ◽  
Vol 29 (4) ◽  
pp. 394-397 ◽  
Author(s):  
G. Gay ◽  
A. Josserand ◽  
R. Bardin
Keyword(s):  
Organic Compounds ◽  
Yeast Extract ◽  
Nitrifying Bacteria ◽  
Energy Sources ◽  
Organic Substrates ◽  
Mixotrophic Conditions

The influence of organic compounds (pyruvate, yeast extract, and peptone) was tested on two Nitrobacter serotypes. In mixotrophic conditions, these compounds caused swelling of the cells. As shown by immunofluorescence, multiplication of the nitrifying bacteria still occurred in the absence of nitrite. Although growth was slower under such conditions, the organic substrates were used as energy sources. However, the response of the different serotypes studied varied and this could explain the fluctuations of the two nitrifying populations in the soil.

scholarly journals Production mechanism and characteristics of dissolved organic nitrogen derived from soluble microbial products (SMPs-DON) in a drinking water biological aerated filter

2019 ◽  
Vol 19 (7) ◽  
pp. 1994-2000
Author(s):  
Jia Kang ◽  
Shu-li Liu ◽  
Teng-fei Ma ◽  
Xu Gao
Keyword(s):  
Drinking Water ◽  
Biological Treatment ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Illumina Miseq ◽  
Soluble Microbial Products ◽  
Illumina Miseq Sequencing ◽  
Production Mechanism ◽  
Miseq Sequencing ◽  
Microbial Products

Abstract Dissolved organic nitrogen derived from soluble microbial products (SMPs-DON) generated during the drinking water biological treatment process poses a great threat to water supply safety due to the potential carcinogenic risk. To further study the production mechanism and characteristics of SMPs-DON in drinking water biological aerated filtration (BAF), Illumina MiSeq sequencing is applied to characterize the microbial community. In addition, an excitation–emission matrix combined with the parallel factor model (EEM-PARAFAC) and gel filtration chromatography (GFC) are used to analyze the component and molecular weight (MW) distribution of the SMPs-DON. Results showed that the production of SMPs-DON in drinking water BAF can be explained using Illumina MiSeq sequencing from the perspective of the microbial community. Also, according to the EEM-PARAFAC analysis, the fluorescence intensity scores of fulvic-like and humic-like substances were almost unchanged, whereas the scores of protein-like substances first increased and then decreased, which was consistent with the variation in the DON concentration. SMPs produced initially primarily consisted of macromolecules with MW >20 kDa, and then they were degraded and small molecular SMPs with MW <5 kDa accumulated. This study provides theoretical guidance and technical support for ensuring drinking water safety and reducing secondary pollution risks from drinking water biological treatment.

Interpretation of bacterial activities in nitrification filters by a biofilm model considering the kinetics of soluble microbial products

1994 ◽  
Vol 30 (11) ◽  
pp. 147-156 ◽  
Author(s):  
H. Furumai ◽  
B. E. Rittmann
Keyword(s):  
Heterotrophic Bacteria ◽  
Wastewater Reuse ◽  
Drinking Water Treatment ◽  
Ammonium Concentration ◽  
Soluble Microbial Products ◽  
Biological Interactions ◽  
Substrate Removal ◽  
Biofilm Model ◽  
Nonsteady State ◽  
Microbial Products

Activities of heterotrophic bacteria in nonsteady-state biofilms were evaluated using a simplified biofilm model in which formation and exchange of soluble microbial products (SMP) by nitrifiers and heterotrophs were considered. The model was applied to experimental results for a trace-level substrate removal. The model predictions indicated that SMP from nitrifiers contributed to supporting heterotrophic growth and their substrate removal potential. The biological interactions were more significant in cases of low influent substrate COD concentrations and increased with higher influent ammonium concentration. The introduction of SMP kinetics into the model captured the key aspects of removal and formation of COD components in biofilms receiving low influent substrate concentrations, such as nitrification filters for drinking water treatment and wastewater reuse.

Advanced Modeling of Mixed Populations of Heterotrophs and Nitrifiers Considering the Formation and Exchange of Soluble Microbial Products

1992 ◽  
Vol 26 (3-4) ◽  
pp. 493-502 ◽  
Author(s):  
H. Furumai ◽  
B. E. Rittmann
Keyword(s):  
Substrate Concentration ◽  
Biological Process ◽  
Organic Substrate ◽  
Endogenous Respiration ◽  
Soluble Microbial Products ◽  
Main Attention ◽  
Operational Conditions ◽  
Mixed Populations ◽  
Microbial Products ◽  
Bacterial Groups

Biological process modeling is advanced by explicitly describing heterotroph and nitrifier biomass, incorporating formation of soluble microbial products (SMP) from both the bacterial groups, and allowing degradation of SMP by the heterotrophs. Biomass decay now has two parts, endogenous respiration and formation of biomass-associated products (BAP). The model is applied to investigate interactions between heterotrophs and nitrifiers. Main attention is directed to evaluating the role that SMP produced by nitrifiers plays as a supply of organic substrate to heterotrophs and to predicting the COD concentration in the effluent. The model quantitatively describes the observed accumulation of SMP in the effluent at long SRT and at high influent substrate concentration. The significance of SMP from nitrifiers to support growth of heterotrophs is clearly elucidated through the model experiments under various operational conditions. The results indicated that a high NH4+-N/COD ratio in the influent would decrease original substrate COD due to increased heterotrophs whose growth is supported by SMP from nitrifiers, but total COD increases. The minimum substrate concentration, Smin, is reduced for heterotrophs by the additional growth from SMP.

scholarly journals Fate of 14C-Labeled Microbial Products Derived from Nitrifying Bacteria in Autotrophic Nitrifying Biofilms

2005 ◽  
Vol 71 (7) ◽  
pp. 3987-3994 ◽  
Author(s):  
Satoshi Okabe ◽  
Tomonori Kindaichi ◽  
Tsukasa Ito
Keyword(s):  
Heterotrophic Bacteria ◽  
Nitrifying Bacteria ◽  
Fish Analysis ◽  
Bacterial Cells ◽  
Phylogenetic Groups ◽  
Waste Products ◽  
Structural Cell ◽  
Cell Components ◽  
Microbial Products ◽  
Significant Uptake

ABSTRACT The cross-feeding of microbial products derived from 14C-labeled nitrifying bacteria to heterotrophic bacteria coexisting in an autotrophic nitrifying biofilm was quantitatively analyzed by using microautoradiography combined with fluorescence in situ hybridization (MAR-FISH). After only nitrifying bacteria were labeled with [14C]bicarbonate, biofilm samples were incubated with and without NH4 + as a sole energy source for 10 days. The transfer of 14C originally incorporated into nitrifying bacterial cells to heterotrophic bacteria was monitored with time by using MAR-FISH. The MAR-FISH analysis revealed that most phylogenetic groups of heterotrophic bacteria except the β-Proteobacteria showed significant uptake of 14C-labeled microbial products. In particular, the members of the Chloroflexi were strongly MAR positive in the culture without NH4 + addition, in which nitrifying bacteria tended to decay. This indicated that the members of the Chloroflexi preferentially utilized microbial products derived from mainly biomass decay. On the other hand, the members of the Cytophaga-Flavobacterium cluster gradually utilized 14C-labeled products in the culture with NH4 + addition in which nitrifying bacteria grew. This result suggested that these bacteria preferentially utilized substrate utilization-associated products of nitrifying bacteria and/or secondary metabolites of 14C-labeled structural cell components. Our results clearly demonstrated that the coexisting heterotrophic bacteria efficiently degraded and utilized dead biomass and metabolites of nitrifying bacteria, which consequently prevented accumulation of organic waste products in the biofilm.

Anoxic treatment of low-strength wastewater by immobilized sludge

1997 ◽  
Vol 36 (12) ◽  
pp. 135-141
Author(s):  
Gong-Ming Zhou ◽  
Herbert H.P. Fang
Keyword(s):  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
Organic Substrate ◽  
Anoxic Condition ◽  
Scanning Electron Micrographs ◽  
Soluble Microbial Products ◽  
Batch Test ◽  
Effluent Quality ◽  
Microbial Products ◽  
Low Levels

Low levels of phenol and m-cresol were effectively removed from wastewater under anoxic condition using immobilized sludge. A 138-day experiment was conducted using wastewater containing NO3−-N (22.3 mg·1−1), phenol (10 mg·1−1) and m-cresol (5 mg·1−1) at 30°C using sucrose (50 mg·1−1) as co-substrate in an upflow reactor packed with polyvinyl alcohol (PVA) beads entrapped with anoxic sludge and powdered activated carbon (PAC). Throughout the experiment, phenol and m-cresol in the effluent were below the detectable level of 1.0 mg·1−1 even when HRT (hydraulic retention time) was as low as 0.55 hour. The effluent quality in general decreased with HRT. At 5.9 hours of HRT, the reactor effluent contained 5.9 mg·1−1 of COD (chemical oxygen demand) and 1.3 mg·1−1 of NO3−-N; but at 0.55 hour, they were, 17.3 and 5.7 mg·1−1, respectively. The effluent COD was from the unidentified soluble microbial products. Methane was not produced after the startup, and all PVA beads were not disintegrated. Results of a batch test showed that organic substrate was preferably consumed by the denitrify bacteria in favor of methane-producing bacteria. Scanning electron micrographs showed that most bacteria were populated on the bead surface due to the availability of nitrate and substrate.

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