Bacteria growth kinetics

A. Cabrero, S. Fernandez, F. Mirada, J. Garcia, Effects of copper and zinc on the activated sludge bacteria growth kinetics, Water Res. 32 (1998) 1355-1362. 

TABLE 15.1. Summary of growth kinetics of hydrogen-producing bacteria. 

It was considered a stirred tank reactor where the Desulfovibrio Alaskensis (DA) bacteria growth is carried out. The DA bacterium is a sulfate reducing bacteria used, in this case, to degrade some undesirable sulfate compounds to sulfides. It was previously determined that the Monod s kinetic equation adequately describes our reactor [2], where its kinetics parameters were determined via standard methodology in a batch culture [3]. 

Galit Zilberman joined the research group at Drexel in November 2003. Her previous research at Tel Aviv University with QCM measurements at the solution/electrode interface [59] led us to e q)lore the use of the QCM/HCC as a detector of protein-ligand interactions in aqueous solution [60], and as a detector of the growth of E Coli bacteria on thin film of nutrient medium deposited on the QCM [61]. Zilberman also studied the growth kinetics of alkyl- and carboxylic acid self-assembled monolayers (SAMs) on gold and the EDC-catalyzed amide bond formation on a carboxylic acid-tenninated SAM. 

CO2 = Cti + S2 — Z, (f = CO2 + KhPt + qcHi/kLa-, Pt is the total pressure within the digester and qcRi is the molar flow rate of methane. The bacterial growth rates for acetogenic (Ai) and methanogenic X2) bacteria are approached by the Monod and Haldane kinetics... 

While quantifying the sources and sinks of CH4 has been difficult, isotopic measurements of l3CH4 and CH,D4, x are promising. Various sources have characteristic isotopic signatures e.g., as mentioned previously, fossil fuel derived CH4 is depleted in l4C (Lowe et al., 1988, 1994 Wahlen et al., 1989). The sinks of CH4, e.g., reaction with OH, reaction with Cl, and uptake by soil bacteria, also exhibit kinetic isotope effects and these have been used to probe the causes of the observed recent changes in CH4 growth rates (e.g., see Gupta et al., 1996, 1997). Measurements of isotopic... 

Hence, sometimes phenomena associated with enzyme kinetics control the rate of biotransformations. If suitable enzymes are present in the microbial community, for example due to consumption of structurally related growth substrates, then we may see immediate degradation of compounds of interest like BQ when they are added to these metabolically competent microbial communities (Fig. 17.17). For such cases, if the abundance of the bacteria is varied, the rate of removal changes accordingly. Consequently, the removal of BQ could be described by a second-order rate law (Smith et al., 1978) ... 

Beek and Frissel (1973) Growth of nitrifier and ammonifer bacteria by Michaelis-Menten kinetics NH4 oxidation by first-order kinetics with environmental variables mineralization of proteins, sugars, cellulose, lignin, and living biomass by first-order kinetics immobilization by first-order kinetics including considerations for microbial biomass and C/N ratio NH3 volatilization by diffusion NH4 clay fixation by equilibrium model. 

As shown in Fig. 6B, a two-phase pattern occurred for the substrate uptake. It can be observed that during the exponential growth phase, sucrose assimilation by the bacteria was small, corresponding to about 20% of the initial amount introduced into the medium. However, after a 40-h process corresponding to the end of the growth phase, there was a rise in the substrate uptake, suggesting that the carbon source was directed to biosurfactant production, for the conditions tested. It should be emphasized that the fermentative process, when the medium was supplemented with microsalts and EDTA (Fig. 6A), generated a different substrate kinetics in comparison with that obtained for the nonsupplemented medium (Fig. 6B). 

Ion transport is also often coupled with cellular energy production and with nutrient and product membrane transport. Aside from Papoutsakis work on the influence of methanol transport on growth of methanol-consuming bacteria, the importance of membrane control of nutrient and product fluxes into the cell has been largely ignored by biochemical engineers [25]. Better methods for measuring the pH and electrical potential differences across cell membranes are needed, as is more careful consideration of membrane-mediated processes in cell kinetics models. 

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