A solid state theory of oxidative phosphorylation

A theory of oxidative phosphorylation utilizing phonons for energy transfer and chemical bond formation is presented. It is hypothesized that the phonons released during redox reactions of the electron transport chain can be propagated through the lattice structure of the proteins concerned with coupling. Energy loss of the phonons through rapid thermalization is prevented by hydrophobic bonding which serves as a thermal insulator of the lattice from the external environment. It is shown that respiratory control, reversed electron flow, uncoupling interchangability of energy among sites, utilization of two electron transfer to accomplish one bond formation are compatible with this theory. Experimental tests for the theory are proposed.     

Production of Cyclosporin A by solid state fermentation

The production of Cyclosporin A using wheat bran as the solid substrate was attempted using Tolypocladium sp. and it was found that the yield was 10 times more than the yield obtained by submerged fermentation. Hydrolysing the wheat bran using dilute HCl was found to increase the yield. Different solvents were used for the optimization of extraction of Cyc A from the fermented bran.     

A mathematical model for solid state fermentation in tray bioreactors

A simple mathematical model for the interaction of mass transport with biochemical reaction in solid state fermentations (SSF) in static tray type bioreactors under isothermal conditions has been developed. The analysis has enabled scientific explanations to a number of practical observations, through the concept of critical substrate bed thickness. The model will be most useful in the prediction of the concentration gradients as also in efficient design of these bioreactors.List of Symbols C g/cm³ Oxygen concentration in the bed - C _g g/cm³ Atmospheric oxygen concentration - C ^* Dimensionless oxygen concentration, C/C _g - D _e cm²/h Effective diffusivity - H cm Bed thickness or height - H _c cm Critical bed thickness or height - H _m cm Maximum height of zone of zero oxygen concentration - p _i mg/(g · h) Productivity (Eq. 13) - R g/(cm³ · h) Biochemical reaction rate - t h Fermentation time - t ^* Dimensionless time, D _e t/H² - X mg/cm³ Biomass concentration - X _max mg/cm³ Maximum biomass concentration - y Dimensionless thickness or height, (y = z/H) - y cm Thickness of zone of zero oxygen concentration (Eq. 12) - Y Yield coefficient - z cm Bed thickness or height along tray axis - Bed void fraction - _max h^–1 Specific growth rate - Thiele modulus      

Bioelectrochemical signal monitoring of in-vitro cultured cells by means of an automated microsystem based on solid state sensor-array

In the last decade, fundamental advances in whole cell based sensors and microsystems have established the extracellular acidification rate monitoring of cell cultures as an important indicator of the global cellular metabolism. Innovative approaches adopting advanced integrated sensor array-based microsystems represent an emerging technique with numerous biomedical applications. This paper reports a cell-based microsystem, for multisite monitoring of the physiological state of cell populations. The functional components of the microsystem are an ion sensitive field effect transistor (ISFET) array-based sensor chip and a CMOS integrated circuit for signal conditioning and sensor signal multiplexing. In order to validate the microsystem capabilities for in-vitro toxicity screening applications, preliminary experimental measurements with Cheratinocytes, and CHO cells are presented. Variations in the acidification rate, imputable to the inhibitory effect of the drug on the metabolic cell activity have been monitored and cell viability during long term measurements has been also demonstrated.     

Penicillin production by solid state fermentation

Summary Penicillin was produced by a non-sterile solid state fermentation (SSF) on bagasse impregnated with culture medium. The use of concentrated media greatly enhanced the antibiotic production in this system. It was observed that adequate initial moisture content (70%) of the impregnated solid medium results in higher production. A comparison between solid and liquid fermentation showed superior yield and productivity.     

Prebiotic peptide-formation in the solid state

The reactions of glycine with inorganic polyphosphates in the solid state have been studied. The formation of peptides up to the decamer occurs at moderate temperatures(r.t.-100 degrees C) in the presence of imidazole and magnesium chloride. If adenosine 5' -monophosphate is added to the reaction mixture, 2'(3') -o-glycyl adenosine 5'-monophosphate is also obtained. These reactions could have occurred on the primitive earth.     

Engineering aspects of solid state fermentation

Engineering aspects of solid state fermentation have not been available in spite of the recent interest in the technique and the appearance of a number of reviews on this subject. The present state of the art regarding substrate uptake, oxygen transfer, growth characteristics, growth estimation, control systems for maintaining parameters, mathematical models, design of fermenters and automation of fermentations does not provide a detailed insight. The work carried out at the Central Food Technological Research Institute, Mysore, on the development of a large-scale solid state fermenter, comparative cost estimation of SSF and submerged fermentation as well as development of know-how for production of a variety of food enzymes, has led to the commercial exploitation of the technology by industry. Future R&D needs in this area, neglected at present but yet so promising, are indicated.     

Prebiotic peptide-formation in the solid state

When a solution containing gly-N-pa and imidazole is evaporated to dryness and then maintained at a temperature between 65 degrees C and 100 degrees C, high yields of AppA and obligoglycines are obtained. We believe that ImpA is formed first, and then activates the carboxyl group of glycine or gly-A-pA. If glycine, ATP or AppA, and imidazole are heated together in the solid state, ImpA is formed and ATP , or indirectly from imidazole and gly-N-pA. Next the carboxyl group or glycine is activated by the ImpA formed in situ. The subsequent reactions of activated glycine leads to the formation of oligoglycines and the 2' (3')-glycylester of pA. Under plausible prebiobic conditions, good yields of oligoglycines up to the octamer can be obtained from glycine, ATP and imidazole.     

Prebiotic peptide-formation in the solid state

The reactions of benzoate ion and of glycine with adenosine 5-phosphorimidazolide have been investigated. Benzoate reacts first to give the anhydride, benzoyl-adenylate, which, in the presence of excess imidazole, reacts further to give the 2'- and 3'-esters of adenosine 5'-phosphate. Glycine also first attacks the imidazolide to give an anhydride, but this compound may react further either to give 2- and 3'-esters or to form peptides, depending on the reaction conditions.     

A novel bacterial thermostable alpha-amylase system produced under solid state fermentation

Summary A novel thermostable alpha-amylase system produced byBacillus HOP-40 at neutral pH under solid state fermentation gave three peaks in descending order at pH 5.0, 8.5–9.0 and 7.0.     

Bioreactor designs for solid state fermentation

Solid state fermentation has gained renewed attention not only from researchers but also from industry. This technique has become a more and more attractive alternative to submerged fermentation for specific applications due to the recent improvements, especially in the design. This paper reviews the various reactor designs and focuses on the differences between lab-scale and industrial-scale designs. It highlights the main designs that have emerged over the last 10 years and the potential for scaling-up for each category of reactor.     

Comparison of solid and solution state protein structures. Photoacoustic study of solid state bovine methemoglobin derivatives

In an effort to examine the consequences of phase state changes on protein structures, optical absorption spectra of several bovine hemoglobin derivatives in lyophilized, ammonium sulfate-precipitated, and crystalline states were examined. Absorption spectra were used to compare protein conformations. Differences between solution and several solid state spectra were apparent. They were greatest for lyophilized preparations, were inhibited by ligand binding, the tightest binding ligand being the most effective inhibitor, and were substantially or totally reversible upon dissolving the solid state protein. Though the magnitude of spectral changes varied, they all indicated characteristically different proportions of the protein were converted to a reversible hemichrome in each type of solid state preparation. The extent of hemichrome formation was correlated with the degree to which the protein tends to be dehydrated in each solid state preparation. This may reflect the role of water in determining the three-dimensional structure of hemoglobin. Absorption spectra of solid state hemoglobin preparations were obtained from photoacoustic spectra using a novel method for spectral analysis. Results presented here demonstrate the utility of this procedure in probing structures of solid state proteins.     

Optimization studies on the production of cyclosporin A by solid state fermentation

Several parameters including (a) tray fermentation with and without perforation (b) thickness of solid substrate bed (c) type of inoculum (d) size of inoculum (e)?effect of relative humidity were studied for the optimum production of Cyclosporin A by solid state fermentation using Tolypocladium sp. The results indicate that while perforations in the trays had no significance on the yield of Cyc A, the other parameters had an influence on the production of Cyc A. The results indicate that under the optimized conditions, Cyc A can be produced in bulk quantities economically.     

A convenient method to measure water activity in solid state fermentation systems

The proximity equilibration cell (PEC) method previously developed for measurement of water activities in the high ranges for dairy products has been adapted for solid state fermentation systems and found to be convenient and useful.     

Energy balance in solid state fermentation processes

It was applied a macroscopic energy balance to a solid state fermentation process and an electron balance in order to estimate the temperature and the heat evolved in the process. There were employed several equations that describe the development of the system and offer the possibility to design or control such fermentations.