Stimulation of heterotrophic nitrification and N2O production, inhibition of autotrophic nitrification in soil by adding readily degradable carbon

Anoxic and aerobic batch reactor assays using a two-by-two factorial design were developed to determine the potential activity of autotrophic denitrification and heterotrophic nitrification in biological nutrient removal (BNR) activated sludge systems, especially those accomplishing simultaneous BNR (SBNR). Results from the application of these assays to three full scale closed loop bioreactors previously documented to be accomplishing SBNR demonstrated that these activities were minimal in comparison with the conventionally recognized activities of heterotrophic denitrification and autotrophic nitrification. Activity within the mixed liquor consistent with current theories for phosphorus accumulating organisms (PAOs) was also observed. Along with other observations, this suggests the presence of PAOs in the facilities studied.

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15N tracing model SimKIM to analyse the NO and N2O production during autotrophic, heterotrophic nitrification, and denitrification in soils

Isotopes in Environmental and Health Studies ◽

10.1080/10256010500230205 ◽

2005 ◽

Vol 41 (3) ◽

pp. 261-274 ◽

Cited By ~ 24

Author(s):

Florian Stange ◽

Frank Döhling

Keyword(s):

Heterotrophic Nitrification ◽

N2o Production ◽

15N Tracing ◽

Nitrification And Denitrification ◽

15N Tracing Model

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Performance of Aerobic Denitrification by the Strain Pseudomonas balearica RAD-17 in the Presence of Antibiotics

Microorganisms ◽

10.3390/microorganisms9081584 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1584

Author(s):

Yunjie Ruan ◽

Lei Cai ◽

Huifeng Lu ◽

Meng Zhang ◽

Xiangyang Xu ◽

...

Keyword(s):

Metabolic Pathways ◽

Negative Impact ◽

Engineering Application ◽

Aerobic Denitrification ◽

N2o Production ◽

Significant Negative Impact ◽

Practical Engineering ◽

Production Trend ◽

Pseudomonas Balearica ◽

Stimulation Of

Aerobic denitrification, one of the important nitrate metabolic pathways in biological denitrification, has been attracting increasing interest recently due to its functional advantages. In order to evaluate the effect of antibiotics on aerobic denitrification and guide practical engineering application of aerobic denitrification techniques, we evaluated the performance of aerobic denitrification by the strain Pseudomonas balearica RAD-17 in the presence of ciprofloxacin (CFX) and oxytetracycline (OTC). No significant negative impact on the performance of aerobic denitrification in the presence of CFX or OTC within the range of 50 to 300 μg L−1 was found. Significant degradation of OTC was found within the range of 50 μg L−1 to 300 μg L−1 under aerobic denitrification conditions, while no degradation was found for CFX. Stimulation of cell growth occurred within the investigated range of antibiotics. Under anoxic or aerobic conditions, the addition of CFX or OTC changed the N2O production trend. The results in the present study may play an important role in informing the use of aerobic denitrification techniques in the presence of antibiotics within environmentally relevant concentrations (<1 mg/L).

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Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066917 ◽

1971 ◽

Vol 29 ◽

pp. 570-571

Author(s):

E. A. Elfont ◽

R. B. Tobin ◽

D. G. Colton ◽

M. A. Mehlman

Keyword(s):

Chemical Composition ◽

Rat Liver ◽

Future Study ◽

Mode Of Action ◽

Liver Mitochondria ◽

Rat Liver Mitochondria ◽

Effective Inhibitor ◽

Biochemical Effects ◽

Glycerophosphate Dehydrogenase ◽

Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

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Gap junctions in the prothoracic glands of the tobacco hornworm, Manduca sexta

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123933 ◽

1992 ◽

Vol 50 (1) ◽

pp. 706-707

Author(s):

Ji-da Dai ◽

M. Joseph Costello ◽

Lawrence I. Gilbert

Keyword(s):

Gap Junctions ◽

Small Molecules ◽

Manduca Sexta ◽

Freeze Fracture ◽

Cell Communication ◽

Cellular Level ◽

Thin Sections ◽

Prothoracic Glands ◽

Polyhydroxylated Steroids ◽

Stimulation Of

Insect molting and metamorphosis are elicited by a class of polyhydroxylated steroids, ecdysteroids, that originate in the prothoracic glands (PGs). Prothoracicotropic hormone stimulation of steroidogenesis by the PGs at the cellular level involves both calcium and cAMP. Cell-to-cell communication mediated by gap junctions may play a key role in regulating signal transduction by controlling the transmission of small molecules and ions between adjacent cells. This is the first report of gap junctions in the PGs, the evidence obtained by means of SEM, thin sections and freeze-fracture replicas.

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