8 Matching Results

Search Results

Advanced search parameters have been applied.

Process development studies of the bioconversion of cellulose and production of ethanol. Semi annual report

Description: Progress in the following process development studio is reported: economic evaluation of hydrolysis and ethanol fermentation schemes, economic evaluation of alternative fermentation processes, raw materials evaluation, and evaluation of pretreatment process. Microbiological and enzymatic studies reported are: production of cellulase enzyme from high yielding mutants, hydrolysis reactor development, xylose fermentation, and xylanese production. Fermentation and separation processes include: process development studies on vacuum fermentation and distillation, evaluation of low energy separations processes, large scale hollow fiber reactor development. (MHR)
Date: April 1, 1981
Creator: Wilke, C.R. & Blanch, H.W.
Partner: UNT Libraries Government Documents Department

Process development studies on the bioconversion of cellulose and production of ethanol

Description: Preliminary studies show minimal conversion of wood by sulfur dioxide at pressures of 38 psi at room temperature. Evaluation studies of Rut-C-30 and Rut-L-5 Trichoderma viride strains were compared. Studies on the continuous production system by manipulating temperature, pH, Tween 80 level substrate concentration, and dilution rate were performed. The known major components of cellulases were characterized. Studies on the reduction of the cost of producing sugar from corn stover were performed. Development of medium for continuous ethanol fermentation is discussed. Experiments show that the growth limiting factors for continuous fermentation were in the yeast extract. Biotin, pantothenic acid, and pyridoxine appear to be growth limiting factors. Addition of other vitamins had no effect on cell yield but increased ethanol production. The flash ferm process is discussed. Utilization of hemicellulose sugars is described. (DC)
Date: December 1, 1979
Creator: Wilke, C.R. & Blanch, H.W.
Partner: UNT Libraries Government Documents Department

Protein-salt binding data from potentiometric titrations of lysozyme in aqueous solutions containing KCl

Description: An existing method for potentiometric titrations of proteins was improved, tested and applied to titrations of the enzyme hen-egg-white lysozyme in aqueous solutions containing KCl at ionic strengths from 0.1 M to 2.0 M at 25 C. Information about the protein`s net charge dependence on pH and ionic strength were obtained and salt binding numbers for the system were calculated using a linkage concept. For the pH range 2.5--11.5, the net charge slightly but distinctly increases with increasing ionic strength between 0.1 M and 2.0 M. The differences are most distinct in the pH region below 5. Above pH 11.35, the net charge decreases with increasing ionic strength. Preliminary calculation of binding numbers from titration curves at 0.1 M and 1.0 M showed selective association of chloride anions and expulsion of potassium ions at low pH. Ion-binding numbers from this work will be used to evaluate thermodynamic properties and to correlate crystallization or precipitation phase-equilibrium data in terms of a model based on the integral-equation theory of fluids which is currently under development.
Date: March 1, 1997
Creator: Engmann, J.; Blanch, H.W. & Prausnitz, J.M.
Partner: UNT Libraries Government Documents Department

Effect of secondary structure on the potential of mean force for poly-L-lysine in the alpha-Helix and beta-sheet conformations

Description: Because poly-L-lysine (PLL) can exist in the {alpha}-helix or {beta}-sheet conformation depending on solution preparation and solution conditions, PLL is a suitable candidate to probe the dependence of protein interactions on secondary structure. The osmotic second virial coefficient and weight-average molecular weight are reported from low-angle laser-light scattering measurements for PLL as a function of NaCl concentration, pH, and {alpha}-helix or {beta}-sheet content. Interactions between PLL molecules become more attractive as salt concentration increases due to screening of PLL charge by salt ions and at low salt concentration become more attractive as pH increases due to decreased net charge on PLL. The experimental results show that interactions are stronger for the {beta}-sheet conformation than for the {alpha}-helix conformation. A spherically-symmetric model for the potential of mean force is used to account for specific interactions not described by DLVO theory and to show how differences in secondary structure affect PLL interactions.
Date: October 30, 2001
Creator: Grigsby, J.J.; Blanch, H.W. & Prausnitz, J.M.
Partner: UNT Libraries Government Documents Department