A study was performed to understand the fermentation process for production of glutathione fermentation (GSH) with an improved strain of baker's yeast. Simultaneous utilization of sugar and ethanol has been found to be a key factor in the industrial process to produce GSH using Saccharomyces cerevisiae KY6186. Based on this observation, the optimal sugar feed profile for the fed-batch operation has been determined. A feedforward/feedback control system was developed to regulate the sugar feed rate so as to maximize GSH production yields. Using the feedforward/feedback control system and the on-line data of oxygen and ethanol concentration in exhaust gas, the successful scaleup to the production level was accomplished. An average of 40% improvement of glutathione production compared to a conventionally programmed control of exponential fed-batch operation was found in the new process.
SynopsisSedimentation constant and intrinsic viscosity were measured on purified tropocollagens extracted from earthworm-cuticle and lathyritic ratskin. A Cartesian diver viscometer was used t o make viscosity measurements at small shear stress and to avoid the effects of surface forces. By comparing the experimental data with the hydrodynamic theories of wormlike-coil of Ullman a value of 1300 d has been assigned for the persistence length of these tropocollagens. Other factors which may affect the estimate are discussed.
Hydrodynamic properties of monodisperse poly(a-methylstyrene) were studied in dilute benzene solutions, both concentration and molecular weight being varied. Molecular weight determination was performed by three methods, osmometry, light scattering and sedimentation equilibrium. The intrinsic viscosity was found to be [r;] = (1.034± 0.05) x 10-4 M 0 • 72 dl/g at 30°C, where Mis the molecular weight. The sedimentation coefficient extrapolated to zero concentration and one atmosphere was found to be so 0 =(3.61 ± 0.03) x 10-15 M 0 • 43 sec. The Scheraga-Mandelkern constant f3 was evaluated as (2.43±0.03) x 106 which was independent of Mand in agreement with the value previously obtained in theta solvent. The concentration dependence of sedimentation coefficient was found to be compatible with the recent theory by Pyun and Fixman.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.