bluuebunny/crossref_metadata_2025 huggingface dataset:
Vortex behavior in the waldhof fermentor
Authors: Tsao George Tsu Ning
Published: December 2004

This is the first part of a systematic study on the mechanisms of the Waldhof fermentor. When an agitator is rotating in a liquid, a vortex will develop on the surface. Air is dispersed into the liquid when the vortex is deep enough to reach the agitator. This is the basic mechanism of air dispersion in a Waldhof fermentor. In this work, experimental results, empirical correlations, and theoretical equations were obtained to relate the vortex depth to a number of physical factors including agitator diameter, agitator speed, tank diameter, liquid depth, liquid viscosity, and so on. The vortex depth was found a function of both Reynolds number and Froude Number.
Mathematical representation of batch culture data
Authors: Edwards Victor H. , Wilke Charles R.
Published: December 2004

A generalized logistic equation is proposed for the mathematical representation of batch culture kinetic data. Properties of the equation are discussed. A computer program is used to fit the generalized equation to both artificial and actual batch culture data. The equation is shown to be capable of fitting data exhibiting lag, exponential, deceleration, stationary, and death phases, as well as diauxic growth. The fitted equation is useful for differentiation, interpolation, and other manipulations of the data, and it is a convenient means of data storage.
Apparatus for simultaneous spectrophotometric and polarographic measurements
Authors: Ribbons D. W. , Hewett A. J. W. , Smith F. A.
Published: December 2004

We have recently constructed a 10‐mm, light path quartz cuvet which will accept a Clark oxygen electrode; it is temperature controlled and is suitable for use in a Unicam (Cambridge, England) SP 800 recording spectrophotometer. Several enquiries have prompted this publication, although such an apparatus was mentioned much earlier by Chance and Williams,1 and has been used extensively.

Figure 1a, b, c, and d and their legends provide sufficient detail for the construction of the cuvet and provision of the commercially available electrode, quartz faces, stirring motor and disk magnet. Circuit diagrams for temperature control (range 22–38°C., ± 0.2°C.) and stirrer speed control are shown in Figure 2a and b. The cuvet is shown situated in the spectrophotometer cell housing in Figure 3, and the cuvet with its associated equipment is shown in Figure 4.
Hydrolysis of RNA to 5′‐nucleotide by seed sprouts, particularly malt sprouts
Authors: Laufer Louis , Gutcho Sidney
Published: December 2004

Conditions for the efficient conversion of commercial RNA to nucleoside 5′‐monophosphate by means of a phosphodiesterase in malt sprouts have been determined. A comparison of the enzyme content of the rootlets, stems, and kernels of various plant seedlings, including barley, rye, oat, wheat, rice, and beans shows maximum amounts in the rootlets, and minimum quantities in the ungerminated kernels. Of all the seedlings tested, (mung bean, soy bean, oat, wheat, rice, barley) barley gave the highest conversion of RNA to 5′‐nucleotides. Commercial malt sprouts prepared from 6 different malted barleys including 2‐rowed and 6‐rowed samples all showed about the same amount of phosphodiesterase content. Besides phosphodiesterase, other enzymes capable of hydrolyzing RNA and 5′‐nucleotides were found in sprouts. These included 3′‐phosphodiesterases, 5′‐nucleotidases, and nucleosidases. By carefully pretreating both extracts and the solid sprouts at elevated temperatures for a limited time and by the addition of minimum amounts of Zn+2, the action of these undesirable enzymes was either effectively destroyed or minimized so that the production of 5′‐nucleotides was maximized. It was found that suspensions of appropriately washed and treated barley malt rootlets are substantially more effective than aqueous extracts for converting RNA to 5′‐nucleotides.
Fermentative production of 5′‐purine ribonucleotide
Authors: Nara T. , Misawa M. , Kinoshita S.
Published: December 2004

Micrococcus sodonensis KY 3765 and Arthrobacter citreus KY 3155 were found capable of accumulating IMP in media supplemented with hypoxanthine as a precursor. High concentrations of phosphate and magnesium salts were required for high yields of IMP. Manganese deficiency in the media was also essential. Excessive Mn2+ effects were also seen in the IMP fermentation carried out with an adenineless mutant, of Cornynebacterium glutamicum. In M. sodonensis, R5P‐like substances, 5‐phosphoribose pyrophosphokinase and IMP pyrophosphorylase, were leaked out, of the cells grown in suboptimal Mn2+ levels. This excretion was inhibited by high levels of Mn2+. Such a phenomenon was not noted in A. citreus. An adenineless mutant (KY 7208) of Brevibacterium ammoniagenes was found to accumulate an appreciable amount of IMP. The chemical changes in this fermentation showed that, hypoxanthine was first produced de novo, excreted, and then reconverted into IMP by a salvage pathway. When hypoxanthine was added to 7208 culture, IMP yield was increased appreciably. In fact exogenous 14C‐hypoxanthine was incorporated into 14C‐IMP. Subsequent experiments showed that indeed Br. ammoniagenes ATCC 6872, a parent culture of KY 7208, was able to produce IMP, GMP, and AMP, in good yield from hypoxanthine, guanine, and adenine, respectively.
Synthesis of guanosine and its derivatives from AICA‐riboside
Authors: Kumashiro I. , Yamazaki A. , Meguro T. , Takenishi T. , Tsunoda T.
Published: December 2004

A novel and convenient method for the synthesis of guanosine is described. The reaction of AICA‐riboside with sodium methylxanthate gave 2‐mercaptoinosine in almost quantitative yield. The latter was oxidized with hydrogen peroxide to afford inosine‐2‐sulfonic acids, which was readily animated to give guanosine in excellent yield. Similarly, the preparation of N2‐methylguanosine and N2,N2‐dimethylguanosine, minor constituents of transfer RNA, was also accomplished. Furthermore, this procedure was extended to the synthesis of 2′,3′‐O‐isopropylideneguanosine and the isopropylidene derivatives of various N2‐substituted guanosines from 2′,3′‐O‐isopropylidene‐AICA‐riboside. Guanosine via 2′,3′‐O‐isopropylideneguanosine was successfully phosphorylated to give 5′‐guanylic acid.
The preparation of rat‐liver mitochondria by conventional differential centrifugation and by zonal Centrifugation, after various disruption procedures: A comparative study
Authors: Klucis E. , Lloyd D. , Roach G. I.
Published: December 2004

Rat liver was subjected to three different, disruption procedures (homogenization, explosive decompression, and Chaikoff press) and mitochondria were subsequently isolated by conventional differential Centrifugation and by zonal Centrifugation. The properties of these mitochondria were investigated by polarographic measurement of oxygen uptake and they were examined by electron microscopy. All three methods of disruption gave mitochondria which showed respiratory control. Nitrogen cavitation gave the most reproducible conditions for cell breakage and zonal Centrifugation gave good separation of subcellular organdies in extracts produced by this method. Some separation of the heterogenous mitochondrial populations was achieved by zonal Centrifugation.
Properties and biological activity of a new peptide antibiotic (Colisan)
Authors: Leon Shalom A. , Bergmann Felix
Published: December 2004

Colisan has the formula Lys3Val4Leu3IleTyr and a molecular weight of approximately 1500. Neither N‐terminal nor C‐terminal group have been found. The peptide is highly resistant to hydrolysis by proteolytic enzymes (pepsin and trypsin). The ϵ‐amino groups of lysine are indispensable for biological activity, since either deamination or acetylation completely inactivates Colisan. A comparative study with basic peptides like polylysine demonstrated their similarity of action, on one hand, and an antagonistic effect to Colisan, on the other. The fast action of the antibiotic and the specific effect on the cell membranes of many different biological systems (Entameba, Paramecium, erythrocytes, smooth muscle, and others) support the hypothesis that the primary damage occurs in the membrane with consequent alteration of permeability. The leakage of intracellular material (histamine) from mast cells after application of Colisan is in accord with this hypothesis. The results strongly suggest that the biological activity of the peptide is based essentially, but not exclusively, on its basic character.
Toxic spiroepoxy compounds from Fusaria and other hyphomycetes
Authors: Bamburg J. R. , Marasas W. F. , Riggs N. V. , Smalley E. B. , Strong F. M.
Published: December 2004

Many hyphomyceteous fungi have been found to produce closely related toxic metabolites which form the class of compounds called scirpenes. The structures of those compounds are reviewed and current studies on their biological activity and possible implication in moldy corn poisoning are discussed.
Response of biological waste treatment systems to changes in salt concentrations
Authors: Kincannon D. F. , Gaudy A. F.
Published: December 2004

The effect of NaCl on the yield of biological solids and on the ability of continuously cultured heterogeneous microbial populations to remove substrate was assessed by changing the salt concentration in the inflowing synthetic waste. During the period of increasing the salt concentration to 30,000 mg/l the system could not maintain a high substrate removal efficiency. However, after an acclimation period the system regained its former efficiency. Upon diluting the salt out of the system, a significant rise in cell yield was noted as the salt level passed through the range 8,000–10,000 mg/l. It was found that steady operation at a salt level of 8,000 mg/l sustained the cell yield at a high level.
Genetic control of virus production in cell lines
Authors: Walker Jerry S. , Lincoln Ralph E. , Weirether Francis J.
Published: December 2004

A procedure to maintain genetic control of virus production in tissue cell lines, has been proposed and discussed. Both the tissue cell which replicates the virus and the virus inoculum must be homogeneous in order to produce a product with the expected characteristics. Certain philosophical and technical aspects of the problem are discussed in relation to developing and maintaining genetically homogeneous stock cultures, inoculum, and product.
Decigram quantities of pure foot‐and‐mouth disease virus from cell cultures
Authors: Bachrach Howard L. , Polatnick Jerome
Published: December 2004

Baby‐hamster kidney (BHK) cell cultures grown in rolling 2‐liter Baxter bottles are used for the production of foot‐and‐mouth disease virus (FMDV) which is subsequently purified. The bottles are held securely in round wire racks (19 per rack) and rotated on a three‐tiered roller mill. The use of a strongly buffered growth medium makes changes of the medium unnecessary. A sheet of aluminum foil is used to seal the cultures. It is pressed tightly over all the bottles in a rack by means of a polyurethane foam sheeting bonded to the underside of a rigid snap‐on cover. Special equipment eliminates removing the bottles from the racks at any stage in their use. The loaded racks fit directly onto headers of a glassware washer. Spent cell growth media and virus fluids are collected by inverting an entire rack of bottles‐Current production is 400 BHK cultures (21 racks) containing 8 × 108 cells each after 6 days growth. About 344 of these cultures (18 racks) are used to grow virus. The purification process yields about 113 mg of pure FMDV per week; the overall recovery based on infectivity is 32%. The projected maximum production of purified virus in the present facilities is approximately 2.5 times greater than this amount.
A multisurface tissue propagator for the mass‐scale growth of cell monolayers
Authors: Weiss R. E. , Schleicher J. B.
Published: December 2004

Various multisurface mass‐scale tissue culture propagators ranging in capacity up to 200 liters have been developed at Abbott Laboratories. These patented units consist, of an enclosed vessel containing a multiplicity of separated glass plates or disks on which cells may attach and proliferate. Means for mixing and aeration of the medium are provided. Sample ports facilitate the addition of cultures and media, the withdrawal of samples, the washing of cell monolayers, and the harvesting of cells and cell products. The large cell growth surface per occupied volume, the provision for separating tissue cells from media simply and easily, and the minimization of the amount of labor required per cell growth area are some of the many advantages of the multisurface tissue propagator that are described.
A pilot plant for mammalian cell culture
Authors: Moore George E. , Hasenpusch Peter , Gerner Robert E. , Burns Alex A.
Published: December 2004

Studies of the possible viral etiology of human leukemia have required large quantities of cultured cells derived from human hematopoietic tissues. Since cultures sufficiently large and free from contamination could not readily be produced according to existing methods, a pilot, cell culture plant has been constructed for the production of mammalian cells in mass quantity. 500‐ml to 20‐liter trophocell units have already proved to be scientifically and economically practical, as they provide good reliability, excellent growth rates, and sustained yield of human cells. 200‐liter stainless steel culture units have now been added to the trophocell system. Five complete 200 liter units are now in operation. The design of the original stainless steel unit was based on that of a stainless steel, jacketed soup kettle. There are no openings in the vessel other than those in the lid, which provide convenient access points for sampling, sensor probes, etc. Environmental parameters, e.g., liquid level, temperature, and pH, are monitored and controlled with commercially available apparatus. Many initial problems connected with the new 200 liter units have been resolved, but operational and design problems remain in the areas of stable instrumentation, cell harvesting, salvaging and reuse of unspent media components, establishment of physiologic steady stale, recovery of virus‐containing cells with reculture of the remaining unaffected cells, and the recovery and separation of cell components and special products such as immunoglobulins, interferons, and hormones. A definitive cell plant with culture units of 20, 50, 250, and 1250 liters is now being constructed.
Effect of centrifugation on the viability of Burkitt lymphoma cells
Authors: Wang Daniel I. C. , Sinskey Tony J. , Gerner Robert E. , De Filippi Richard P.
Published: December 2004

This study reports some findings on the effects of centrifugation on the viability of mammalian cells. The authors used Burkitt lymphoma cells cultivated in a synthetic medium containing 10% fetal calf serum for all experiments. Batch centrifugations were conducted in a RC2‐B centrifuge (Ivan Sorvall, Incorporated, Norwalk, Connecticut USA) operated at 0 and 25°C. During centrifugation we exposed the cells to gravitational fields ranging from 24,800 to 42.200g. The results showed that at, 0°C and 25,800 or 42,000g no loss in cell viability occurred for up to 90 min exposures in the centrifugal field. However, at 25°C and for gravitational fields of 24,800 and 42,000g, there were appreciable losses in cell viability. Continuous centrifugation studies in the Sharples supercentrifuge (Division of Penn Salt Corporation, Warminister, Pennsylvania USA) were also conducted with bowl speeds up to 28,000 rpm (19,000g) and flow rates ranging from 1.4 to 20 1, hr. Slight, losses in cell viability were noted and postulated as caused by the shear stresses encountered by the cells. Some pumping studies using the lymphoma cells substantiate this conclusion.
The zonal centrifuge applied to the purification of a low‐yield virus in human leukemia cells
Authors: Toplin I. , Boyden R. , De Padova A. , Brandt P. , Sottong P.
Published: December 2004

The herpes‐type virus found in certain cell cultures derived from Burkitt's lymphoma, other human leukemias, and normal human leukocytes, was concentrated and partially purified by large‐volume density gradient centrifugation using zonal centrifuge systems. Using the Jiyoye (P‐3) cell line as a model, rate‐zonal runs on disrupted cell suspensions in sucrose gradients yielded concentrates with high virus particle counts when 10–15 ml of packed cells were processed per liter of gradient. Isolation and removal of cell nuclei or fluorocarbon treatment of cell sonicates permitted virus recovery from larger volumes of cells per experiment. Zonal centrifugation of concentrated cell‐free spent media from highly infected cell cultures yielded more purified virus than obtained from cells. Viral concentrates were prepared with particle counts of 1010–1011/ml and total protein concentrations of 0.2–0.5 mg/ml. Subsequent isopyenie‐zonal centrifugation of the various high‐count virus fractions from the zonal centrifuge showed a heterogeneity in buoyant virus density ranging from 1.18 to 1.27 in potassium tart rate. The spread in virus density was attributed to the different morphological forms of the virus observed by electron microscopy.
New directions in the production of vaccines
Authors: Overman John R.
Published: December 2004

New trends and developments in vaccines emphasized the growing need for safety tests of increased complexity, rather than a need for ultrasophisticated and complex devices. The Vaccine Development Branch of the National Institute of Allergy and Infectious Diseases, operating with an annual budget of $6,000,000 has the task of expediting the collaborative efforts of 50 laboratories for developing, producing, and testing experimental vaccine lots. Rubella has a major priority; other priorities are assigned to respiratory syncytial, parainfluenza, adenoviruses, influenza, and rhinoviruses, and Mycoplasma pneumoniae. To accomplish this requires a very expensive and complex program involving rapid information exchange and increased emphasis on safety testing with regard to extraneous viruses and the oncogenic potential of the vaccines. The latter need resulted from such experience as that with the Salk vaccine and the tumorproducing potential of some adenoviruses. Electron microscopy has been useful in discovering possible viral contaminants. Of all material produced for experimental work, from 65 to 70% is used for safety tests.
A method for aeration and foam control in fermentation vessels
Authors: Worthington G. R. L. , Wolochow H. , Chatigny M. A.
Published: December 2004

The production of large quantities of microbial mass, or their by‐products, frequently requires aeration and mixing of fluid media. This operation often results in copious production of foam which cannot be exhausted with the effluent air or gas. Foam is usually controlled with antifoam agents which may interfere with product purity, oxygen uptake, and with subsequent product, handling. The process herein described obviates the requirement for antifoam agents or other foam‐control methods. In essence, the air (or other gases) and foam in the headspace are continuously withdrawn, entrained in the intake side of a self‐priming pump, and reintroduced into the bulk of the process liquid medium. The headspace may be enriched with oxygen or other gases.
Rocker cell culture incubator
Authors: Tunnah Kenneth V. , McLimans William F. , Moore George E.
Published: December 2004

A rocker mammalian cell culture system is described. The basic mechanical component is a special incubator with contained rocker culture trays. The system provides for precise environmental temperature regulation with intermittent rocking of contained cultures in such a manner as to permit thin fluid overlay of cells with maximum accessibility to oxygen while circumventing the problems of evaporation, substrate depiction, etc.
Kinetics of gas diffusion in mammalian cell culture systems. II. Theory
Authors: McLimans William F. , Blumenson Leslie E. , Tunnah Kenneth V.
Published: December 2004

Mathematical models have been constructed which relate the depth of the culture fluid overlay to the oxygen available to mammalian cells cultured under static conditions. These models suggest that the maintenance of a given rate of oxygen utilization by some culture systems may be critically depended on this fluid depth and on the solubility and rate of diffusion of oxygen in the culture fluid. The importance of these concepts as applied to the isolation and growth of differentiated cells representative of the tissue of origin are noted.
Simultaneous gas–liquid interfacial oxygen absorption and biochemical oxidation
Authors: Tsao George T.
Published: December 2004

Two experimental methods were used in measuring oxygen‐transfer rates. The results indicate that two possible mechanisms are operating in simultaneous gas–liquid interfacial oxygen absorption and biochemical oxidation. One of the mechanisms, the direct absorption mechanism, has not been much studied in bioengineering. Mathematical equations are derived to describe the simultaneous mechanisms.
The cultivation of animal cells at controlled dissolved oxygen partial pressure
Authors: Kilburn D. G. , Webb F. C.
Published: December 2004

A 3‐liter culture vessel has been developed for the growth of animal cells in suspension at controlled pH and dissolved oxygen partial pressure (pO2). The culture technique allows metabolically produced CO2 to be measured; provision can be made to control the dissolved CO2 partial pressure. In cultures containing a low serum concentration, gas sparging to control pO2 was found to cause cell damage. This could be prevented by increasing the serum concentration to 10%, or by adding 0.02% of the surface‐active polymer Pluronic F68. The growth of mouse LS cells in batch culture without pO2 control was found to be limited by the availability of oxygen. Maximum viable cell populations were obtained when dissolved pO2 was controlled at values within the range 40–100 mm Hg.
Large‐Scale isolation of acid phosphatase from human erythrocytes
Authors: Fisher R. A. , Harris H. , Houldsworth M. , Lilly M. D. , Dunnill P.
Published: December 2004

A laboratory process for the isolation of type B acid phosphatase from human erythrocytes has been scaled up 80 times. The enzyme was purified 1300‐fold by adsorption on calcium phosphate gel, ammonium sulfate precipitation, and gel filtration. The yield was 27%. Results for the type A enzyme are also presented.
Application of continuous oxidative assimilation and endogenous protein synthesis to the treatment of carbohydrate wastes deficient in nitrogen
Authors: Gaudy A. F. , Goel K. C. , Gaudy Elizabeth T.
Published: December 2004

A synthetic waste (with glucose as carbon source) devoid of a source of nitrogen was purified in a laboratory scale pilot plant by a new modification of the activated sludge process. The process makes use of a separate carbon assimilation (oxidative assimilation) phase and an endogenous phase in which ammonia is added to a portion of the settled sludge and non‐nitrogenous products stored in the cells in the assimilation phase are converted to protein. It was found that sludge so treated, when recycled to the assimilation tank, could carry out continuous oxidative assimilation of the waste. Various COD:N ratios were studied. At the highest, 70:1, 90% purificaton efficiency was achieved.
Animal cell cultures as a source of hormones
Authors: Tashjian Armen H.
Published: December 2004

Current methodology now makes it possible to establish in culture a variety of mammalian cells which perform organ‐specific functions during serial propagation for periods of months or years. This report describes the results of experiments with animal and human cells that produce growth hormone, adrenocortical steroid hormones, thyrocalcitonin, and parathyroid hormone. Within the next decade it should be possible to use cell culture methods for manufacturing purposes to produce hormones and other valuable cellular products which are difficult to obtain in other ways. At first it may be necessary to use neoplastic cells for this purpose; but evidence is accumulating to suggest that it may eventually be possible to establish in culture normal, functional animal and human cells.
Dynamic behavior of the chemostat subject to substrate inhibition
Authors: Yano Toshimasa , Koga Shozo
Published: December 2004

A theoretical study was made on the dynamic behavior of a single‐vessel continuous fermentation subject to a growth inhibition at, high concentration of the rate limiting substrate. Phase plane plotting and stability analysis showed three steady states to exist; namely, a “washout”; state, a nontrivial stable state, and an unstable state. Whether the system attains a nontrivial steady state or is to be washed‐out depends upon the initial values of the cell and/or substrate concentration(s). Since this property is a characteristic feature of the present system, an experimental procedure was suggested to insure a stable operation in practice.
Effect of high substrate concentration and cell feedback on kinetic behavior of heterogeneous populations in completely mixed systems
Authors: Ramanathan M. , Gaudy A. F.
Published: December 2004

Growth kinetics of heterogeneous populations of sewage origin were studied in completely mixed reactors of the once‐through type at a high concentration of incoming substrate, 3000 mg/l glucose, and in systems employing cell feedback or sludge recycle at an incoming substrate concentration of 1000 mg/1 glucose. The recycle flow rate employed was 25% of the incoming feed flow, and the concentration of cells in the recycle was maintained as closely as possible at 150% of the cell concentration in the reactor. Studies were made at various dilution rates. Throughout these studies, batch experiments using cells grown at the various dilution rates were made to determine ks and μm values. As in previous studios using heterogeneous populations, the relationship between specific growth rates μ and substrate concentration S was represented better by the Monod equation than by any other which was tested. The growth “constants” μm, ks, and Y were found to fall in the same general range as those determined in previous studies in once‐through systems operated at 1000 mg/l glucose. It was observed that cell recycle, even at the relatively low concentration factor employed in these studies, greatly enhanced the flocculating and settling characteristics of the cells.
Measurement of heat evolution and correlation with oxygen consumption during microbial growth
Authors: Cooney C. L. , Wang D. I. C. , Mateles R. I.
Published: December 2004

A procedure for measuring the rate of heat production from a fermentation has been developed. The method is based on measuring the rate of temperature rise of the fermentation broth resulting from metabolism, when the temperature controller is turned off. The heat accumulation measured in this manner is then corrected for heat losses and gains. A sensitive thermistor is used to follow the temperature rise with time. This procedure is shown to be as accurate as previous methods but much simpler in execution. Using this technique, the rate of heat production during metabolism was found to correlate with the rate of oxygen consumption. Experiments were performed using bacteria (E. coli and B. subtilis), a yeast (C. intermedia), and a mold (A. niger). The substrates investigated included glucose, molasses, and soy bean meal. The proportionality constant for the correlation is independent of the growth rate, slightly dependent on the substrate, and possibly dependent On the type of organism growth. This correlation has considerable potential for predicting heat evolution from the metabolism of microorganisms on simple or complex substrates and providing quantitative parameters necessary for heat removal calculations.
Kinetics of fermentation processes
Authors: Kono T. , Asai T.
Published: December 2004

Kinetic studies on fermentation processes were made and a general equation of production rate was newly presented applying the kinetic theory on mierobial cell growth which was reported previously by the authors.l,2 Equations for product concentration in fermentation time courses were derived by developing mathematically the general equation of production rate, and characteristic properties of fermentation processes were clarified. Some examples of fermentations were analyzed kinetically using the new kinetic theory. The calculated values of product, and cell concentrations were in good agreement with the observed values.
The design, construction, and characteristics of a new long‐lived steam sterilizable oxygen electrode
Authors: Brookman J. S. G.
Published: December 2004

A steam sterilizable oxygen electrode for fermentor use is described. The electrode has a silver cathode, lead anode, phosphate electrolyte, and a membrane of a fluorinated ethylene‐propylene copolymer film (FEP.).

The electrode has a linear response to partial pressure of oxygen from 1.5 × 10−2 to 103 mm Hg.
Composition of cell material and biological value of the cellular protein of a micrococcus strain grown on hydrocarbons
Authors: Ertola R. J. , Mazza L. A. , Balatti A. P. , Sanahuja J.
Published: December 2004

A Micrococcus cerificans strain was grown on simple media with n‐hexadecane or gas oil as sole carbon sources. Samples of cellular material recovered from hexadecane or gas oil fermentations do not appear to differ significantly in their composition. The protein content varied from 68 to 75%. With the exception of sulfur amino acids the amino acid distribution compares favorably with the FAO standard reference protein.

The biological value of cell protein recoveered from hexadecane fermentations was 67 (cascin, 70). In the case of gas oil grown cells, the cell material recovered had to be completely purified in order to improve its protein quality. After fully extraction of undersirable fraction with petroleum ether in a Soxhlet apparatus the biological value observed was 63.
Kinetics of microbial oxidation of n‐heptane. I. Characterization of the process
Authors: Çaǧlar M. A. , Thompson A. R. , Houston C. W. , Rose V. C.
Published: December 2004

Utilization of n‐heptane by a Pseudomonad was studied in pilot‐size butch cultures. Optimal pH and temperature were determined by a factorial design and a medium based upon mineral uptake rates was formulated. High cell yields were obtained by volatilizing heptane in the incoming air and thereby achieving good hydrocarbon dispersion. Hydrocarbon carried by effluent gases was recovered and recycled. In cultures where pH is not controlled, decrease in the electrolytic conductivity of the medium was found to be indicative of viable cells and was used in monitoring bacterial propagation. If not checked, increase in salinity in pH controlled cultures was found to affect cell production negatively. Viscosity changes were not very significant. Heptane to aqueous medium ratio was found to affect oxygen supply to the system due to higher dissolved oxygen concentrations associated with hydrocarbons.
Fermentation of 1‐hexadecene by Candida lipolytica
Authors: Klug M. J. , Markovetz A. J.
Published: December 2004

Candida lipolytica, strain Phaff, was grown on 1.0% 1‐hexadecene as sole source of carbon. Several oxidative intermediates were isolated and identified. Based on these intermediates two pathways are proposed for the degradation of the 1‐alkene via the methyl group and the double bond. Subterminal oxidation of the 1‐alkene was also indicated. Cell yield, lipid content, fatty acid profile and 1, 2‐diol concentration are given for various rates of aeration during growth in a fermentor.
Effect of alkylbenzenes on n‐alkane utilization
Authors: Traxler R. W. , Bernard J. M.
Published: December 2004

It has been shown that alkylbenzenes which do not support growth of Pseudomonas aeruginosa exert a stimulatory or inhibitory effect on the utilization of n‐alkanes by this organism. The effect is a function or the number of methyl substitutions to the benzene ring and the concentration of aromatic hydrocarbon. The alkylbenzenes have been shown to exert the stimulatory and inhibitory effect, on all phases of growth. The data suggests different mechanisms involved in the inhibition by benzene and p‐xylene but a similar mechanism by all of the stimulatory compounds. Warburg data demonstrates changes in the rate of oxygen uptake in the presence of trimethylbenzene at different stages of the fermentation. The release of water soluble material in the presence of trimethylbenzene suggests a permeability effect on the cells.
Growth models of cultures with two liquid phases. II. Pure substrate in dispersed phase
Authors: Erickson L. E. , Humphrey A. E.
Published: December 2004

Mathematical models which can be used to describe batch frowth in fermentations with two liquid phases are developed for systems in which the growth limiting substrate is the dispersed liquid phase. Three special cases are considered assuming pure substrate in the dispersed phase and a decreasing interfacial area due to substrate consumption. In the first, it is assumed that all growth occurs at the surface of the dispersed phase. In the second and third growth occurs at the interface and in the continuous phase. The second case assumes substrate equilibrium between the two phases while the third assumes substrate consumption in the continuous phase is limited by rate of substrate transport to that phase. Since the amount of growth at the interface and substrate transport to the continuous phase depend on the interfacial area, two limiting cases for the decrease of interfacial area with substrate consumption are also considered in this investigation. The first and third models are compared with available experimental data.
Growth models of cultures with two liquid phases. III. Continuous cultures
Authors: Erickson L. E. , Humphrey A. E.
Published: December 2004

Some mathematical models, which have been used to describe batch growth in fermentations with two liquid phases present, are used to predict the behavior of continuous fermentations in a chemostat. Two types of dispersed systems are considered in this investigation. In the first, type, it is assumed that the composition of the dispersed phase is such that, increased substrate utilization results in a decreased substrate concentration with no change in the interfacial area. In the second type of system, the dispersed phase is assumed to be pure substrate; therefore, the substrate concentration in the dispersed phase remains constant but the interfacial area is affected by changes in dilution rate. Three special cases are examined for each type of system in order to examine the effect of the interfacial area, the phase equilibrium constant, and the mass transfer coefficient on system performance. Comparison of two of the models with available experimental data shows fair agreement, between model and data.
A laboratory‐scale press for extracting juice from leaf pulp
Authors: Davys M. N. G. , Pirie N. W. , Street G.
Published: December 2004

A press is described with which loads of up to 1 ton can be applied quickly to 1 kg quantities of leaf pulp spread over 450 cm2. The juice extracted is similar in quantity and quality to that extracted by large‐scale equipment. Evidence is presented that the conditions of pressing are so uniform that the yields of juice are consistent.
Regulation of biosynthesis of secondary metabolites. I. Biosynthesis of chlortetracycline and tricarboxylic acid cycle activity
Authors: Hošťálek Z. , Tintérová Marta , Jechová Vendulka , Blumauerová Margita , Suchy J. , Vanék Z.
Published: December 2004

In the course of submerged cultivation of low‐production and industrial production strains of Streptomyces aureofaciens, the activity of enzymes of the tricurboxylic acid cycle was studied. The activities of citrate synthase (EC 4.1.3.7), aconitate hydratase (EC 4.2.1.3), isocitrate dehydrogenase (EC 1.1.1.42), fumarate hydratase (EC 4.2.1.2), and malate dehydrogenase (EC 1.1.1.37) were estimated spectrophotometrically in cell‐free preparations. In the growth phase, mainly the initial reactions of the cycle were active with both strains. In production‐phase, the activities of enzymes in the low‐production strain were 2–5 × higher than in the production strain. Benzylthioeyanate, at a concentration of 5 × l0−5M, stimulated chlortetracycline production of both strains with accompanying decrease in activity of the enzymes of the tricarboxylic acid cycle. The role of the tricarboxylic acid cycle in control of chlortetracycline biosynthesis is discussed.
A steam‐sterilizable electrode of the galvanic type for the measurement of dissolved oxygen
Authors: Van Hemert P. , Kilburn D. G. , Righelato R. C. , Van Wezel A. L.
Published: December 2004

An oxygen probe is developed, using the principle of the silver‐lead galvanic cell, covered with a plastic membrane. It is steam sterilizable while filled with water; after sterilization, water is easily exchanged for the electrolyte, potassium bicarbonate. Flat plastic membranes up to a thickness of about 0.1 mm can be applied. The membrane is secured and stretched in a special way, which guarantees a leakproof seal. The outer shape of the probe has a tulip‐form and consists of polished stainless steel, except for the electrode face. The electrode is suitable for laboratory and industrial use and its components are completely standardized.

Almost linear response for O2‐partial pressures up to atmospheric is obtained with 0.001 in. and 0.002 in. FEP‐Teflon membranes. 90% response time is of the order of 10–15 sec for the 0.001 in. membrane, Residual current is almost negligible (< 1 μA).
The effect of Eh on regulatory processes in facultative anaerobes
Authors: Wimpenny J. W. T.
Published: December 2004

On increasing aeration rate in chemostat cultures of E. coli the redox potential (Eh) of the culture changes from −l50 mv to +250 mv. During this period only a slight increase in measured dissolved oxygen concentration is observed.

It is suggested that Eh be used as a control variable for aeration in the oxygen limited growth condition, whilst dissolved oxygen concentration be used as control variable in the presence of excess oxygen.

Change in cytochrome b1, three tricarboxylic acid cycle enzymes and hydrogenase can be related to culture Eh. These changes are discussed.
Increased oxygen mass transfer rates from single bubbles in microbial systems at low reynolds numbers
Authors: Wise D. L. , Wang D. I. C. , Matelles R. I.
Published: December 2004

The presence of microorganisms have been shown to increase by over 40% the mass transfer rates from small oxygen bubbles at low Reynolds number flow. This increase was found to be due only to the microbe cells as inert particles disrupting the quasi‐static liquid surface film surrounding the gas bubble and thus decreasing the gas‐liquid interfacial resistance. The observed increase in oxygen mass transfer rates was not dependent on cell viability, no effect was noted due to cell‐liquid interfacial resistance, nor was the phenomenon due to altering the physical properties of the liquid during cell propagation. These results were obtained in a unique plexiglass apparatus designed for observing under a microscope a small (0.4 mm dia.) stationary oxygen bubble collapsing into a flowing fluid. The oxygen bubble was injected by a small hypodermic needle and the fluid was suspensions of the yeast Candida intermedia, the bacterium Pseudomonas ovalis, 0.3μ alumina, as well as base points of cell free broth and pure water. Several well‐known chemical inhibitors of oxidative phosphorylation were used to limit cell oxygen uptake. Calculations of oxygen mass transfer rates were compared with the semi‐empirical model of Frössling, the circulating sphere model of Levich, and the rigid sphere concentration boundary layer model of Fried‐lander, the latter two showing strong Reynolds number dependence that may be due to radial fluid motion.
Use of pH and pE measurements during methane biosynthesis
Authors: Pohland F. G. , Mancy K. H.
Published: December 2004

Methane biosynthesis within the anaerobic ecosystem results from the diphasic conversion of complex organic substrates through a series of biologically mediated oxidation‐reduction reactions which arc pH dependent. Routine parametric analysis of the products emanating from the corresponding acid and methane fermentation phases of the anaerobic digestion process provide a basis for determination of process condition and efficiency. Of these analyses, pH and electrode potential of pE are intensive parameters of considerable significance but for which interpretation is often difficult and misleading. Attention has been focussed on the analogy and distinction between pH and pE determinations and their application to the anaerobic ecosystem. Theoretical and practical limitations are discussed and experimental evidence presented which supports the possible use of pH and pE determinations for process evaluation and control.
An improved french pressure cell
Authors: Millbank J. W. , Neale M. J.
Published: December 2004

A description is given of a needle valve press for disrupting cells and microorganisms. The main features of the design are reproductibility and ease of control of the needle valve settings due to absence of screw threads, case of dismantling and cleaning, and the availability of a wide range of alternative piston and cylinder sizes.
Model identification of the biochemical oxidation process
Authors: Naito M. , Takamatsu T. , Fan L. T. , Lee E. S.
Published: December 2004

A fairly general model of the biochemical oxidation, which takes into account the activity of microorganisms, is presented. Parameters of the model have been determined by fitting the model to available experimental data through the use of a straightforward gradient technique.
Semi‐continuous culture and monitoring system for temperature‐synchronized Euglena
Authors: Terry O. , Edmunds L. N.
Published: December 2004

A temperature‐synchronized, semi‐continuous culture and monitoring system is described, with results from use of the system for autotrophically growing Euglena. Outflow from the culture vessel consists of measured samples taken automatically at 2‐hour intervals and fixed for later counting. Inflow is by siphon feed, which restores the culture level after each sampling. The interpretation of growth curves obtained from such cultures is discussed from the viewpoint, of division synchrony and cell cycle studies, and some general comparisons are made between batch and continuous cultures for such studies.
Continuous phased culture—A technique for growing, analyzing, and using microbial cells
Authors: Dawson P. S. S. , Kurz W. O. W.
Published: December 2004

Continuous phased growth produces a culture in which most of the cells in the population are in the same stage of their development. The cell, thereby amplified by the size of the synchronous population, may be examined in the phased culture at any desired growth rate. Changes taking place in the cell after the cell cycle, i.e., post‐cycle changes, may be examined by a modification of the procedure. Further systematic applications of the method permit a rational approach to problems of cell growth and metabolism.

The phasing technique recognizes the cells as the fundamental unit for experimental investigation, and offers a great potential in the analysis of the cell throughout its cycle, a relatively unexploited field in cell physiology and fermentation. Experiments with yeasts and bacteria illustrate some of the applications and progress made so far.
Effect of total illumination upon continuous Chlorella production in a high intensity light system
Authors: Matthern Robert O. , Kostick John A. , Okada Isao
Published: December 2004

A high intensity light system (HILIS) was designed and constructed to define the environmental parameters affecting production of algae. The HILIS incorporates the basic concepts of an aerobic fermenter for heterotrophic cells with high intensity illumination for photosynthetic studies. Of nine parameters considered, temperature and light intensity studies using Chlorella 71105 have been completed. Total illumination was varied from 25,000 to 300,000 lumens (30 times intensity of sunlight as measured at earth's surface) in 7.7–1, culture. The effect of illumination upon growth was measured as cell concentration and total daily algal production when operating the HILIS as a continuous system at a dilution rate of 0.91 per day.

Growth may be expressed as a long function of illumination. A maximum algal concentration of 25.5g/l., dry weight basis, was attained at 300,000 lumens.
Homogeneous cultivation of animal cells for the production of virus and virus products
Authors: Van Hemert P. , Kilburn D. G. , Van Wezel A. L.
Published: December 2004

Homogeneous technique facilitates the cultivation of large quantities of cells, reduces the risk of contamination by eliminating many manipulations, and makes practical the control of conditions such as pH and oxygen tension. Although most animal cells will not multiply in free suspension, certain cell lines have lost the requirement of being attached to a solid surface. These cells can be subcultured indefinitely but have some resemblance to cancer cells such as their abnormal karyotype. Certain cell linen developed from human embryonic tissue maintain their diploid character after repeated subculture and would seem to be ideal for the production of vaccines. However, strict regulations exist for viral products for human injection in that only cells taken from normal tissue and subcultured but once may be used.

A microcarrier method in which cells adhere to DEAE‐Sephadex beads permits a suspension culture which may be termed quasihomogeneous. The attached cells may be retained by sedimentation or by screening as the medium is replaced. Cell debirs from the original tissue is difficult to remove from microcarrier cultures; modifications of the trypsinization technique have alleviated but not solved this problem.

Conditions for virus replication can be less critical than those for cell growth in that oxygen tension seems to have little influence on virus production. In cases where rate of virus production increases with specific growth rate of cells, homogeneous culture would have a advantage in maintaining a high cell mogeneous culture would have a valuble advantage in maintaining a high cell growth rate for a longer time. Some virus infections destroy cells, but others cause little change in cellular mteabolism except that virus is continually produced. The latter type can be conducted with a microcarrier in continuous culture with a virus titer exceeding 107 plaque forming units per milliliter for over 50 days with Rubella‐infected BHK cells.
Predator‐prey relationships in a model for the activated process
Authors: Canale Raymond P.
Published: December 2004

The primary objective of this paper was to develop a mathematical description for the food chain,
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Because of the interdependence of the elements in this food chain, continuous oscillations among the variables are possible. A set of three differential equations was obtained to describe the above system in a continuously fed stirred tank reactor. The differential equations obtained were examined to characterize the possible types of solutions. A limit, cycle solution was obtained for some values of the system parameters.