Electroenzymology in membrane-mimetic media.
Explore the source record for details and available documents.
Bacterial Proteins↗
Biomedical subjects
H G Monbouquette
Publications and source records attributed to H G Monbouquette.
A structured model for immobilized cell kinetics.
An intrinsic, structured model has been formulated to describe the kinetics of viable (living) cells immobilized within porous supports. Predictions of steady-state internal biomass concentration distributions, biocatalyst substrate profiles, and immobilized cell growth and leakage from the support are in qualitative agreement with the literature. Simulation studies indicate that carrier pore structure is a particularly important design variable to be optimized.
Catalysis↗
Effective diffusivity of galactose in calcium alginate gels containing immobilized Zymomonas mobilis.
The effective diffusivity of galactose was measured for calcium alginate gel membranes containing immobilized live Zymomonas mobilis cells at concentrations ranging from 0 to 150 g dry wt/L of gel. Since galactose is not taken up by living Z. mobilis organisms, the diffusion of this representative six-carbon sugar could be studied independently of sugar consumption. Various immobilized biomass loadings were achieved by two different techniques: addition of biomass at known concentrations to the sodium alginate solution before membrane formation and growth of cells in the gel to various biomass concentrations. The highest immobilized cell concentration, attained by in situ growth, corresponds to the maximum of this system, as growth beyond this maximum concentration led to disintegration of the gel membrane. The galactose effective diffusivity measurements for both methods of immobilized cell loading overlap within experimental error and follow the same general monotonic decline with entrapped biomass concentration. Most of the data fall below the upper bound predicted by Hashin and Shtrikman (1962) and show good agreement with the random pore model of Wakao and Smith (1962, 1964). Available effective diffusivity data from the literature provide evidence that the random pore model is an excellent predictor of sugar effective diffusivity in gel immobilized cell systems in general.
Alginates↗
Biomimetic metal-sorbing vesicles: Cd2+ uptake by phosphatidylcholine vesicles doped with ionophore A23187.
Unilamellar phosphatidylcholine vesicles, harboring the ionophore, A23187, in the bilayer and the water-soluble chelating agent, nitrilotriacetate, in the vesicle interior, rapidly sequester and concentrate Cd2+ from dilute aqueous solution. Metal-sorbing vesicle permeabilities for cadmium ion at 5 ppm (42.8 microM) ranged from 8.09 x 10(-7) to 1.27 x 10(-4) cm/s for surface A23187 concentrations of 0.22-2.27 pmol/cm2 (which correspond to lipid:carrier molar ratios of 2000:1 to 200:1) and pH's from 5.5 to 8.5. The Cd2+ permeability shows linear variation with carrier concentration under the conditions studied. As pH is decreased, an increasing fraction of the A23187 becomes protonated, and the permeability exhibits a positive linear relationship with a function related to that for the fraction of unprotonated carrier. These noncovalently assembled, metal-sorbing vesicles exhibit shelf lives of several months and remain stable throughout typical metal sorption studies.
Adsorption↗