Maintenance energy model for microbial degradation of toxic chemicals in soil

Hess, Thomas F.; Schmidt, Steven K.; Colores, Gregory Michael

doi:10.1016/s0038-0717(96)00054-5

Cited by 6 publications

(6 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This would be in reasonable agreement with the predicted value of 4 g if the yield or maintenance substrate utilization were actually lower by a factor of 2 than those assumed for these calculations. Maintenance coefficients 10 times smaller than the one used here have been found in other cell systems (Hess et al, 1996). Even with the same cells the substrate consumption for maintenance can vary fivefold, depending on what limits cell growth [substrate (n-butanal), phosphate, or potassium] (Wübker and Friedrich, 1996).…”

Section: Acclimation Time and Biomass Growthmentioning

confidence: 52%

“…Despite trying a broad range of variables in the simple model used here, the decrease in activity after peaking always took only a few days and could not be extended for long periods as seen in the data. However, a rapid decline has been seen both experimentally and computationally in other systems (Hess et al, 1996;Tros et al, 1996).…”

Section: Resultsmentioning

confidence: 99%

“…Although maintenance metabolism is a standard concept, it has not been applied to biofilter kinetics in spite of the closely related assumption of no net cell growth. However, consideration of combined growth and maintenance utilization of substrate has recently appeared in analyses of bioremediation of contaminated soil (Hess et al, 1996), stirred bioreactors (Tros et al, 1996), and trickling filter operation (Diks et al, 1994). Overall, the lack of a clear physiological basis for the presumed biofilter kinetics raises questions about the predictive accuracy of the prior mathematical models, even if they do provide good numerical fits of test conditions.…”

Section: Other Models Of Biofiltrationmentioning

confidence: 99%

“…The exact form of the growth rate expression is not critical as long as the rate goes to zero as nutrients are depleted. Hess et al (1996) used a logistic model for cell growth that goes to zero as X approaches a predefined maximum, but they did not suggest how that maximum could be estimated a priori. The consumption of nutrients and substrates follow standard formulations:…”

Section: Nutrient Limitation Model Of Acclimationmentioning

confidence: 99%

See 3 more Smart Citations

Shift from growth to nutrient-limited maintenance kinetics during biofilter acclimation

Cherry

Thompson²

1997

Biotechnol. Bioeng.

View full text Add to dashboard Cite

During long‐term operation of a biofilter, the mandatory absence of net cell growth forces the cells into maintenance metabolism, which is of relatively low rate compared to substrate consumption during the active growth of the acclimation phase. A model based on this shift in metabolism can explain the postacclimation decrease in activity sometimes reported for biofilters. The cessation of growth can be caused by nutrient depletion in the bed. Postacclimation nutrient addition increases activity primarily by allowing a return to the high substrate consumption rate of active growth, and only secondarily helps raise bed activity because of the ultimately higher amount of biomass in the bed. Simulations incorporating the acclimation period and the role of maintenance metabolism predict about 4 logarithms of growth during acclimation of a hexane biofilter, which was confirmed experimentally. Changes in a biofilter's biomass during the acclimation phase can be estimated from substrate conversion data using two approximate methods. The first follows the cumulative amount of substrate converted and uses the estimated yield of cells from substrate during active growth to estimate the total biomass created. The second method follows a rate constant for conversion of substrate in the bed. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 330–339, 1997.

show abstract

Section: Acclimation Time and Biomass Growthmentioning

confidence: 52%

Section: Resultsmentioning

confidence: 99%

Section: Other Models Of Biofiltrationmentioning

confidence: 99%

Section: Nutrient Limitation Model Of Acclimationmentioning

confidence: 99%

See 2 more Smart Citations

Shift from growth to nutrient-limited maintenance kinetics during biofilter acclimation

Cherry

Thompson²

1997

Biotechnol. Bioeng.

View full text Add to dashboard Cite

show abstract

“…Based on this work, the researchers argued for a sediment standard. Hess et al (1996) studied the maintenance energy model for microbial degradation of toxic chemicals in soil. Their report dealt primarily with 2,4-dinitrophenol and pentachlorophenol.…”

Section: Water and Wastewatermentioning

confidence: 99%