bluuebunny/crossref_metadata_2025 huggingface dataset:
Foam separation of Escherichia Coli with a cationic surfactant
Authors: Grieves Robert B. , Wang Shing‐Ling
Published: December 2004

An experimental investigation of the foam separation of E. coli from distilled water suspension using a cationic surface‐active agent, ethylhexadecyldimethyl‐ammonium bromide (EHDA‐Br) is presented. Results are evaluated in terms of total cell count, using a membrane filtration technique. Cell concentrations in the initial suspensions are varied from 5.0 × 105 to 1.0 × 108 cells/ml. Surfactant concentrations in the initial cell suspensions are varied from 0.015 to 0.040 mg./ml., and foaming times are varied from 2 to 20 min. The residual quantity of cells decreases exponentially with foaming time to about 0.02% of the initial quantity after 20 min. The cell enrichment ratio, varying from 10 to 1,000,000, is an inverse power function of the initial surfactant concentration and an exponential function of foaming time. Foaminess decreases with increasing initial cell concentrations, and for an initial surfactant concentration of 0.030 mg./ml., the residual cell concentration is a linear function of the initial cell concentration.
Studies on automatically aerated biosynthetic processes. II. Occurrence and elimination of CO2 during penicillin biosynthesis
Authors: Lengyel Z. L. , Nyiri L.
Published: December 2004

Oxygen uptake of Penicillium chrysogenum hyphae growing in automatically aerated deep cultures was the subject of local and periodical change. The change depended on the concentration of carbon dioxide which accumulated in the gas phase of system during the evolution of foam bubbles, and which was suddenly liberated when the foam was destroyed. The actual concentration of sunflower oil added as an antifoaming agent also influenced the oxygen uptake of culture.
Sequential substrate removal by activated sludge after a change in salt concentration
Authors: Kincannon D. F. , Gaudy A. F. , Gaudy Elizabeth T.
Published: December 2004

Previous studies indicated that when cells grown in a NaCl‐free glucose medium were subjected to a high salt concentration, cellular constituents were released which were metabolized by the cells in preference to glucose. In the present study, cells grown on glucose in high salt medium were subjected to a shock loading of salt‐free medium. In this case, the resulting lysate was not used in preference to glucose; the lysate was metabolized only after an acclimation period following glucose utilization. It was shown by injecting chloramphenicol into the reaction liquor during glucose metabolism that new protein synthesis was required in order to metabolize the lysate. This response represents an additional way in which a rapid change in salt concentration can adversely affect biological treatment of waste waters, and a new type of situation in which sequential removal of substrates occurs.
Yield in continuous aerobic bacterial fermentation
Authors: Martin Edward J. , Washington Donald R. , Hetling Leo J.
Published: December 2004

Presented is a mathematical model for the continuous‐flow steady‐state bacterial culture which permits the experimental determination of carbon transfer rates within the system by use of radioactive tracer techniques. The transfer rates are specific for hydraulic loading rates, feed concentrations, type of organism, and substrate, and were incorporated within the existing theoretical description of the growth kinetics in order to elucidate the yield relationships. The carbon transfer rate of cells to soluble organic substrate was observed to exhibit a minimum value at or near dilution rate D = 0.5 hr.−1. A maximum effective yield coefficient, Y, was observed at the same value of D. At dilution rates greater and less than D = 0.5 hr.−1, the cell–substrate transfer rate increased, and effective yield coefficient was observed to decrease. The former showed increases of 50–200%, and the latter exhibited decreases of the order of 10%. The magnitude of these variations would seem to be significant in industrial fermentation processes which utilize continuous microbiological cultures. In light of these findings, the results of other researchers were shown to exhibit maximum effective yield at similar dilution rates or process loadings.
Continuous‐culture system for ecological studies of microorganisms
Authors: Parker R. B.
Published: December 2004

An improved system is presented for measurement of interactions between a number of individual bacterial species. In the procedure, steady‐state populations are fed into a common‐mixed‐culture vessel. Generation times of each species are determined under these conditions and contrasted with generation time in an identical situation in pure culture. Populations for generation time are determined with the aid of differential media. The mechanical system includes three types of peristaltic pumps for media feed and a unit for measurement, recording, and/or control of pH. A new type of anaerobic continuous‐culture vessel which can be inoculated, sampled, and fed continuously is also described. A functional test of a three‐part system including Streptococcus salivarius, Veilloncella alcalescens, and Staphylococcus aureus is presented. An unusual feature was the finding that, under certain conditions, the generation time of S. Salivarius was less than 10 min.
Apparatus for monitoring the oxygen uptake and carbon dioxide production of fermentations
Authors: Jensen A. L. , Schultz J. S.
Published: December 2004

The requirements of the continuous analysis of effluent gas streams from aerated flash and tank fermentors are described, as are instrumental devices for measuring the oxygen and carbon dioxide content of fermentor gases. The use of a specially designed sequential gas sample for monitoring four fermentations simultaneously and a system for precise control of low air flow and pressure is explained. Equations for calculating carbon dioxide production or oxygen consumption rates and respiratory quotients are given. A discussion of the operating characteristics of a device for automatic translation of aeration data between fermentors is presented.
Utilization of normal alkanes by yeasts
Authors: Miller Thomas L. , Johnson Marvin J.
Published: December 2004

A stable mixed yeast culture designated as Culture 4, consisting of Candida intermedia and Candida lipolytica was investigated. The culture was judged stable based on uniformity of fermentation results and the nearly constant ratio of the two organisms at the completion of fermentations. However, the ratio of the two organisms at different times during the fermentation was not determined. The mixed culture grew more rapidly on n‐alkanes than did C. intermedia; C. lipolytica did not grow on unsupplemented mineral salt–n‐alkane medium. Solid n‐alkanes were dissolved in 2,6,0,14‐tetramethylpentadecane (pristane) for investigation as carbon sources. With Culture 4, on n‐alkanes ranging from pentadecane (C15) through octacosane (C28), cell yields were 74.2–89.5%; generation times were 3.0–8.0 hr. during the exponential growth phase. The fastest growth rates and highest cell yields were obtained with docosane (C22) as substrate. The cells obtained contained 6.75–8.81% nitrogen and 1.9–13.4% lipid. Crude protein yields were 34.4–47.6%. The oxidation of n‐alkanes by C. intermedia was studied manometrically with resting whole cells. The alkaneoxidizing system of this organism appears to be constitutive and nonspecific for alkane substrates.
The theoretical aspects of biochemical fuel cells
Authors: Young T. Gray , Hadjipetrou L. , Lilly M. D.
Published: December 2004

Biological systems can be used in three types of fuel cell: depolarization (or concentration) cell, product cell, and redox cell. The possibilities and theoretical limitations of each type of cell have been considered in terms of the metabolic activities of microorganisms and the coupling of these to electrochemical systems. The use of cell extracts and enzymes, particularly in an insoluble form, has been discussed.
Atmospheric nitrogen fixation by hydrocarbon‐oxidizing bacteria
Authors: Coty V. F.
Published: December 2004

Microorganisms have been found which concomitantly convert hydrocarbons, selected naphthenic acids, and atmospheric nitrogen into cellular substance. Bacteria are included in the genera Pseudomonas, Mycobacterium, and Azotobacter. Carbon sources utilized include the hydrocarbons methane, n‐butane, n‐tetradecane, toluene, and a naphthenic acid, cyclohexane‐carboxylate. Uptake of isotopic nitrogen was employed as a criterion of nitrogen fixation. The results indicate a rather wide prevalence in nature of hydrocarbon‐oxidizing bacteria capable of fixing atmospheric nitrogen. Their occurrence helps explain the high concentration of organic nitrogen commonly found in soils exposed to gas leakage from pipelines or natural‐gas seeps, and suggests further consideration of the possibility of applying selected petroleum residua to soils in order to increase the agricultural potential by nitrogen‐fixing processes.
Bacterial degradation of aromatic compounds
Authors: Gibson D. T. , Wood J. M. , Chapman P. J. , Dagley S.
Published: December 2004

The bacterial degradation of catechol, 3‐methylcatechol, 2,3‐dihydroxy‐β‐phenylpropionic acid, and protocatechuic acid has been studied in detail. From the results obtained a general sequence has been proposed for the microbial oxidation of dihydroxy aromatic compounds.
Production of L‐glutamic acid from hydrocarbons: Incorporation of molecular oxygen
Authors: Imada Y. , Takahashi J. , Yamada K. , Uchida K. , Aida K.
Published: December 2004

The production of L‐glutamic acid from hydrocarbons by a newly isolated bacterium, which was identified as Corynebacterium, was investigated. The outstanding characteristic of this bacterium was found to be an accessory requirement of thiamine for growth. The optimum concentration of thiamine for growth was 50 μg./liter, while that for L‐glutamic acid production was 3–5 μg./liter. n‐Paraffins ranging from dodecane to heptadecane were best for L‐glutamic acid production, and about 5 g. of L‐glutamic acid were obtained from 30 g. of these individual n‐paraffins. On the other hand, a tracer experiment using oxygen‐18 revealed that molecular oxygen was incorporated into L‐glutamic acid produced from dodecane. Based on the incorporation value of molecular oxygen in L‐glutamic acid, a hypothetical pathway for the biosynthesis of L‐glutamic acid from dodecane was discussed.
Optimization of a stagewise biochemical reactor system with product feedback
Authors: Wen C. Y. , Chang T. M. , Fan L. T. , Ko Y. C. , Knieper P. J.
Published: December 2004

A consecutive, first‐order, irreversible, biochemical reaction, \documentclass{article}\pagestyle{empty}\begin{document}$ A{\textstyle{{k(\theta)} \over {{\rm Enzyme }1}}} \to B{\textstyle{{k(\theta)} \over {{\rm Enzyme 2}}}} \to C $\end{document}, taking place in a series of N reactors with product recycle is considered. A discrete version of the maximum principle is used to derive general equations necessary for maximizing the production of (1) the final product, C, by choosing the temperature or the pH value in each reactor, and (2) the intermediate product, B, by choosing the reactor volume. A numerical computation for a series of three reactors with recycle is illustrated. The effects of varying the recycle rates on the optimal state and decision variables are also presented.
Foam separation of bacteria with a cationic surfactant
Authors: Grieves Robert B. , Wang Shing‐Ling
Published: December 2004

An experimental investigation is presented of the foam separation of six species of bacteria: Escherichia coli, Serratia marcescens, Proteus vulgaris, Pseudomonas fluorescens, Bacillus cereus, and Bacillus subtilis var niger. A cationic surfactant, ethylhexadeeyldimethylammonium bromide is used and results are evaluated in terms of total cell count, using a membrane filtration technique. From similar neutral distilled water suspensions of the pure cultures (approximately 107 cells/ml.) and using the same operating conditions, ratios of cell concentrations in the residual suspensions to those in the initial suspensions range from 0.0013 for Bacillus subtilis var niger to 0.25 for Serratia marcescens. The presence of bacteria, compared to pure surfactant solutions, produces lower collapsed foam volumes; the foam volumes have a strong influence on the separations achieved with the various species, with enrichment ratios ranging from 27 to 3088 and residual ratios ranging from 0.001 to 0.247.
The utilization of mixed sugars in continuous fermentation. I.
Authors: Baidya T. K. N. , Webb F. C. , Lilly M. D.
Published: December 2004

A strain of Klebsiella aerogenes was selected which gave marked diauxic growth in a batch system on a mixture of glucose and lactose in a simple salts medium; the diauxic lag was 15–20 hr. at 30°C. The growth of this organism on glucose and lactose was studied in a single‐stream two‐stage continuous‐stirred fermentor system over a wide range of flow rates. Glucose was metabolized instantaneously to give very low reactor concentrations at all flow rates, but the time lag before lactose was attacked, when present for the first time, was never less than 40 hr. at low feed rates, rising to 60 hr. at higher rates. The adaptation to lactose of cells in the first vessel lagged behind that in the second vessel but eventually both sugars were completely utilized in the first vessel except at very high dilution rates. At these feed rates, lactose utilization was not only prevented completely in the first vessel but also could be delayed almost indefinitely in the second vessel at the highest dilution rates; thus the lactose passed unchanged through both vessels. Once the enzymes required for lactose utilization had been induced, this ability to use lactose was retained, even in the absence of lactose, for very long periods of time under continuous conditions. Thus on presenting lactose for the second and subsequent occasions it was immediately metabolized. The significance of these results is discussed.
Numerical analysis of reflectance spectra
Authors: Rickard P. A. D. , Moss F. J. , Roper G. H.
Published: December 2004

(1) Samples of yeast which varied over an arbitrary 0–100% scale with respect, to cytochrome concentration were prepared. (2) The reflectance spectrum of each sample was scanned. (3) These reflectance spectra were analyzed numerically on a digital computer to determine the bandwidths and intensities as a function of cytochrome concentration. Band shapes using the profiles of Cauchy, Gauss, and Giovanlelli were used. The correlations may be used to estimate cytochrome concentrations with a standard deviation of about 3%.
Some aroma compounds produced by vinous fermentation
Authors: Webb A. Dinsmoor
Published: December 2004

Various biochemical transformations involved in vinous fermentations are reviewed from the point of view of their formal ion of volatile aroma or flavor compounds in fermented beverages. In addition to the recently elucidated processes for the formation of aliphatic primary alcohols of molecular weight greater than that of ethanol, Nordström's mechanism for the formation of esters during fermentation is discussed. Experimental evidence supporting this mechanism in vinous fermentation is presented; the White Riesling grape is found to contain insignificant, quantities of esters while the wine prepared from these grapes, analyzed immediately after fermentation, shows relatively large amounts of several volatile esters. In addition, in an investigation of an older California sherry, ethyl acid malate is found to be nearly all the single isomer with the hydroxyl group on the carbon adjacent, to the free carboxyl group. This finding suggests an enzymatic (presumably vinous fermentative) production rather than simple chemical esterification in the wine after fermentation. An extension of Nordström's mechanism for ester production is proposed to explain the formation of certain secondary amides found in wines.
Industrial production of disodium 5′‐guanylate
Authors: Kinoshita Kazumoto , Shiro Teruo , Yamazaki Akihiro , Kumashiro Izumi , Takenishi Tadao , Tsunoda Toshinao
Published: December 2004

A process for manufacturing disodium 5′‐guanylate was devised. 5′‐Amino 4‐imidazole carboxamide riboside (AICA‐R) was accumulated with an amount over 100 times those reported in the literature by fermentation of D‐glucose with a non‐exacting purineless mutant derived from Bacillus megaterium JAM 1245) by x‐ray irradiation. The influence of RNA, amino acids, and salts on AICA‐R accumulation was clarified. Appropriate aeration and agitation was found necessary. The (60‐hr, cultivation of the medium containing 8% of D‐glucose gave AICA‐R in the concentration above, 11 g/l. AICA‐R thus accumulated was separated from the fermentation broth by ion‐exchange technique and subjected to synthetic processes to yield disodium 5′‐guanylatc with the yield over 40%, based on AICA‐R.
Large‐scale isolation of prolyl‐tRNA synthetase from Phaseolus aureus
Authors: Dunnill P. , Dunnill P. M. , Houldsworth M. , Boddy A. , Lilly M. D.
Published: December 2004

Some of the problems involved in the scale‐up of enzyme isolation procedures have been examined. In particular the isolation of prolyl‐tRNA synthetase has been investigated. Using a modified procedure (500 × laboratory scale) the enzyme has been separated from 25 kg. of Phaseolus aureus (mung bean) and Partially purified by acid precipitation followed by fractional precipitation with ammonium sulfate. The yield of enzyme was 42 g. (10.5% recovery).
Aflatoxin production by a potent Aspergillus flavus link isolate
Authors: Wildman J. D. , Stoloff L. , Jacobs R.
Published: December 2004

An aflatoxin‐producing isolate of Aspergillus flavus was found to be a consistent producer of aflatoxin on all substrates which supported the growth of the mold. In competition with six other selected molds, this isolate was dominant except with one species of Penicillium. Aflatoxin production was parallel to the extent of A. flavus growth whether effected by substrate or competition.
A new culture flask
Authors: Walsby A. E.
Published: December 2004

A description is given of a large glass vessel suitable for growing algae and other microorganisms in shaken culture. The main feature of the flask is the coneshaped base around which water circultes when the flask is shaken on a reciprocal mechanism.
Concentration of 137Cs, 65Zn, and 85Sr by fresh‐water algae
Authors: Harvey R. S. , Patrick Ruth
Published: December 2004

Differences in the concentration and retention of 137Cs by unicellular diatoms, filamentous green algae, and filamentous blue‐green algae were demonstrated under both batch and continuous‐flow culture conditions. 137Cs concentration factors were generally higher by a factor of 2 in batch tests than in continuous flow tests. In retention studies, 137Cs was desorbed more rapidly from algae under continuous‐flow conditions. Studies with blue‐green algae indicate that 137Cs concentrations in the various species were more closely related to the surface‐to‐volume ratios of algal cells than to the systematic relationships of the three species. Continuous‐flow studies indicated no differences among three species of filamentous green algae in the concentration of 137Cs, 65Zn, and 85Sr. However, the average concentration factors of the radionuclides were considerably different: 3800 for 65Zn, 460 for 137Cs, and 230 for 85Sr. These radionuclides were rapidly desorbed following the transfer of algae to nonradioactive media. The desorption rate was inversely related to the concentration rate.
Metabolic removal of phosphate from sewage effluent
Authors: Levin Gilbert V. , Shaheen Donald G.
Published: December 2004

Eutrophication, or fertilization, has become a major water pollution problem associated with the discharge of mineral‐rich sewage eflluent. A metabolic process to remove dissolved phosphate from sewage through the action of sewage microorganisms is under development. The process, unlike other proposed solutions to the problem, would not require tertiary treatment of the sewage. Laboratory studies have produced promising data. Early reports from municipal sewage treatment plants confirm the expectation that the process may be feasible for widespread use.
Environmental effects on bacterial copper extraction from low‐grade copper sulfide ores
Authors: Ehrlich H. L. , Fox Sally I.
Published: December 2004

In bacterial extraction of copper from low‐grade copper sulfide ores, at least three contributions are made by Thiobacillus ferrooxidans. They are: (1) enzymatic oxidation and consequent solubilization of insoluble sulfides; (2) regeneration of ferric lixiviant for chemical oxidation and solubilization of insoluble sulfides; and (3) partial fixation of externally introduced iron in the ore. Although it is not possible at the present time to measure each of these contributions separately, it is possible to measure the combined contributions. Such measurements reveal a strong dependence of extraction efficiency on various physical, chemical, and biological factors. The following physical factors may affect the rate of bacterial copper extraction: particle‐size of ore, oxygen and carbondioxide supply, oxidation‐reduction potential, pH, temperature, adsorption and ion exchange capacity of ore, and surface tension effects. The following chemical factors may influence the rate of copper extraction: the mineralogy of the ore, the nature of the gangue, the distribution of the sulfide minerals in the host rock, the external supply of ferrous or ferric iron, and the availability of inorganic and organic nutrients. Finally, the following biological agents in addition to T. ferrooxidans may influence the rate of copper extraction: fungi, protozoa, Thiobacillus thiooxidans, and heterotrophic bacteria. Proper control of these various factors is essential for efficient bacterial extraction of copper from low‐grade ore. It is recognized that the foregoing environmental factors also influence chemical copper extraction.
Interfacial phenomena governing adhesion of chlorella to glass surfaces
Authors: Nordin John S. , Tsuchiya H. M. , Fredrickson A. G.
Published: December 2004

Interfacial phenomena are directly involved in the adhesion of a strain of Chlorella, a unicellular alga, to glass surfaces in simple ionic solutions. The principal mechanisms governing the adhesion appear to be electrostatic interaction between electrical double layers and various specific surface interactions resulting from surface heterogeneity and ion adsorption. Under most conditions the algal cells and glass surfaces have negative zeta potentials, and adhesion to glass will not occur; but if, for example, FeCl3 is added to an algal–glass system immersed in 0.05M NaCl, the algal and glass surfaces will possess very different zeta potentials, and adhesion will be strongest under those conditions which produce the greatest, difference in zeta poentials. Prior pretreatment and usage of glass apparatus greatly affect the glass zeta potentials and the adhesion of algal cells to glass. An apparatus for measuring a relative set of numbers representing the force of adhesion of algal cells is described.
Automatic equipment for media sterilization
Authors: Sikyta B. , Mastner J.
Published: December 2004

A device is described based on the principle of a simple analog computer which gives an exact determination of the moment at which the heat energy supply should be interrupted to attain a chosen sterilization effect. The temperature of the medium to be sterilized is measured and at temperatures above 100°C. the dependence of the thermal destruction coefficient of microbial spores on temperature is simulated. This variable is integrated with respect to time and the value of this integral at any given moment corresponds to the sterilization effect, at that moment. The device is also fitted with an extrapolator which evaluates, depending on the instantaneous temperature of the medium, the value of sterilization effect which will be produced during the cooling of the medium after the interruption of the heat, energy supply. The total sterilization effect, in the course of the cycle, is continuously and automatically evaluated as a sum of the integrated sterilization effect and of data supplied by the extrapolator. At the moment when this total sterilization effect attains the prescribed value, the device gives a signal for the interruption of the heat energy supply. The value of the sterilization effect is adjustable within broad limits and its evaluation is performed without substantial simplifying assumptions. By the use of this device an exact scale‐up method for sterilizing media is achieved, yielding at the same time accurate reproducibility of media sterilization. An automatic control of the sterilization cycle is also possible by means of the device.
Working design for a 5‐liter controlled continuous culture apparatus
Authors: Moss F. J. , Bush F.
Published: December 2004

A continuous culture apparatus of 5‐liter capacity is described which is capable of control of dissolved oxygen. Combined turbidostat and constant feed operation permit control of cell population density and one or more nutrients. A system for the measurement of oxygen uptake and CO2 output is described. Sufficient detail is supplied to enable construction and operation of the apparatus.
Studies on continuous enzyme reactions. IV. Preparation of a DEAE‐sephadex–aminoacylase column and continuous optical resolution of acyl‐DL‐amino acids
Authors: Tosa Tetsuya , Mori Takao , Fuse Noriko , Chibata Ichiro
Published: December 2004

Conditions for the preparation of an aminoacylase column using DEAE‐Sephadex as a carrier were investigated. The aminoacylase column having the highest activity was obtained when 7500 μmoles/hr. of partially purified aminoacylase was charged into a column packed with 9 ml. of DEAE‐Sephadex A‐25 (bead type, hydroxy form). By employing a DEAE‐Sephadex–aminoacylase column, conditions for continuous optical resolution of acyl‐DL‐amino acids were investigated. When a solution of 0.2M acetyl‐DL‐methionine (pH 7.0, containing 5 × 10−4M Co2+) or 0.2M acetyl‐DL‐phenylalanine (pH 6.0, containing 5 × 10−4M Co2+) was passed through the aminoacylase column at the flow rate of SV = 2.5 or 2.0, respectively, at 50°C., the highest rate of hydrolysis of both substrates was attained. From the column effluents, enzymatically hydrolyzed L‐methionine and L‐phenylalanine were isolated in a good yield.
Oscillatory growth rate responses of S. Cerevisiae in continuous culture
Authors: Gilley J. W. , Bungay H. R.
Published: December 2004

The yeast S. cerevisiae was grown on dilute, chemically defined media in continuous culture with either glucose or ammonium sulfate as the growth‐limiting ingredient. Changes in dilution rate or glucose concentration induced decaying oscillations in the numbers of yeast growing on ammonium sulfate‐limited media. Spot checks indicated that Cell dry weight and Kjeldahl nitrogen followed the cell numbers during these oscillations. With glucose‐limited media, there was no response to step changes in ammonium sulfate concentration, and dilution rate step changes gave non‐oscillatory transient responses.
Liquid‐metering device for continuous culture
Authors: Johnson Marvin J.
Published: December 2004

A device is described for aseptically metering liquids at rates as low as 10 ml./hr. The metering rate is constant, but can be readily changed. The device delivers a measured increment of liquid every 10 sec. The volume added is controlled by electrical contants in an electrolyte tube. The medium does not enter this tube.
Cultivation of the yeast candida lipolytica on hydrocarbons. I. Degradation of n‐alkanes in batch fermentation of gas oil
Authors: Dostálek M. , Munk V. , Volfová Olga , Pecka K.
Published: December 2004

The growth of batch‐cultivated yeast Candida lipolytica on three kinds of gas oil using mineral medium was studied. A linear dependence was found between the production of yeast biomass and the consumption of n‐alkanes, while the decrease of freezing point of gas oil during cultivation had a distinct course. This disproportion was explained by different degradation of individual n‐alkanes contained in gas oil. The rate of degradation of pentadecane, hexadecane, and heptadecane was the same during the entire cultivation. On the contrary, in the first phase the utilization of shorter chain n‐alkanes, nonane to tetradecane, was more rapid while that of longer chain homologs, octadecane to pentacosane, lagged. Rapid utilization of longer chain n‐alkanes did not occur before the concentration of the other n‐alkanes decreased. Only then the rapid decrease of freezing point appeared.
Growth of mouse fibroblast‐like cells in an autoclavable medium
Authors: Orlando M. D. , Bowersox O. C. , Riley J. M.
Published: December 2004

A relatively simple, autoclavable medium was developed that would support the growth of the mouse fibroblast (MFL) cell line in suspension culture. This medium was prepared in three stages with decreasing quantities of serum. As the serum was reduced from 5% to none, the amount of Bacto‐Peptone was increased from none to 0.5%. The reduction and finally elimination of serum did not affect proliferation adversely, but actually seemed to produce more rapid growth and higher levels of cell population.
A method for determining constants of first‐order reactions from experimental data
Authors: Isaacs W. P. , Gaudy A. F.
Published: December 2004

The authors have utilized a previously proposed mathematical equation (introduced originally for development of empirical equations) as a useful tool for evaluation of first‐order reaction rate constants. By assigning physical significance to the parameter α, the equation can be utilized in obtaining excellent estimates for limiting boundary values and velocity constants.
Microflotation: Coagulation and foam separation of aerobacter aerogenes
Authors: Rubin Alan J.
Published: December 2004

The foam separation technique of microflotation was studied using A. aerogenes as the test organisms. Gas flow rate, collector and alum (when used) concentrations, and frother dose were held constant. In contrast to E. coli, previously reported, A. aerogenes are removed using both lauric acid and laurylamine as the collectors without prior coagulation with alum. The removals are improved after coagulation, with laurylamine being the more efficient collector. In all cases the removals decrease upon increasing the pH above about 8.
Kinetics of microbial cell growth
Authors: Kono Takehiko
Published: December 2004

As a rate equation of microbial cell growth, the Monod equation is widely used. However, this equation cannot fully correspond to real courses of microbial cell growth in many batch cultivations. Especially, predicted values based on this equation do not agree with observed values in many continuous cultivations. In this paper, which introduces new concepts of critical concentration and coefficient of consumption activity, the growth rate equation which corresponds to the whole period including lag period is newly derived and characteristics of microbial cell growth in batch cultivation are clarified. Further, applying the new rate equation to continuous cultivation, a general equation with which to calculate cell concentration is derived and characteristics of microbial cell growth in continuous cultivation are clarified. The calculated values of cell concentration based on the new theory showed quite good agreement with the observed values in both batch and continuous cultivation.
Studies on ventilation of culture broths. I. Behavior of CO2 in model systems
Authors: Nyiri L. , Lengyel Z. L.
Published: December 2004

The rate of dissolution and dehydration of CO2 in a liquid model system was investigated. Components in the model system established the main conditions which may exist, in the extracellular space of a microbiological culture liquid. The charge in voltage of a glass electrode was measured which indicated the formation of H+ ions in the H2CO3 ⇌ HCO H+ reaction. The rate of CO2 hydration increased with the increase of temperature from 0 to 40°C. Likewise the equilibrium of the reaction was shifted towards the forward reaction. Similar results were observed when the tip velocity of the impeller was increased. Data suggest that agitation promotes the dissolution of CO2 in the culture liquid through the reduction of gas‐liquid film resistance in the diffusion of this gas. The rate of hydration of CO2 into the bulk of the liquid was independent of pCO2 above the surface of the liquid but depended on pCO2 in the gas bubble within the liquid. The concentration of HCO was, furthermore, influenced by the buffer components, buffer capacity, and the viscosity of the system. Since pCO2 and the HCO concentration in the extracellular space depend on both physical and chemical factors, the ventilation of a culture liquid necessitates both exhaust of CO2 from the gas bubbles of the culture broth and shift of the H2CO3 ⇌ HCO + H+ reaction towards the backward direction.
Studies with dried airborne vaccinia virus in a small environmental chamber
Authors: Orlando M. D. , Riley J. M.
Published: December 2004

Dried vaccinia virus was found to be very stable in aerosol form in our chamber at a temperature of 75°F and a relative humidity (RH) of 85% when the virus was protected with 1.5% lysine, 1.5% sodium glutamate, 0.5% isoniazid, 0.5% thiourea, and either 2.5% heart infusion broth (HIB) or a combination of 3.75% lactose plus 1.25% raffinose prior to freeze‐drying. Utilization of the Environmental chamber technique resulted in (a) selection of two diluents which protected vaccinia virus against the effects of high relative humidity, (b) measurement of the effect of various chemical additives in the diluents, and (c) quantitative measurement of the moisture absorbed by the various dried products.
Dynamic determination of the thermal characteristics of fermentation tanks
Authors: Falch Edvard A.
Published: December 2004

A method for the determination of total heat generation in a fermentation tank and overall heat‐transfer coefficient at the cooling surface is outlined. These data, which are essential for the design of cooling systems, are measured during the actual fermentation by dynamic analysis of controlled temperature variations. Each experiment consists of two stages: one in which cooling is cut off, and one in which cooling is constant. The necessary temperature variation is so limited that, the course of the fermentation is not affected.
Phosphohydrolases and the production of 5′‐nucleotides by direct fermentation
Authors: Demain Arnold L.
Published: December 2004

A major problem involved in the direct fermentation of nucleotides is their breakdown by phosphohydrolases. Thus, adenine auxotrophs of most microorganisms produce hypoxanthine and/or inosine rather than inosine 5′‐monophosphate (IMP) while guanine auxotrophs excrete xanthosine rather than xanthosine 5′‐monophosphate (XMP). Examination of a Bacillus subtilis mutant producing hypoxanthine plus inosine revealed at least four phosphohydrolases, three of which could attack nucleotides. Even when the extracellular nucleotide phosphohydrolase was inhibited by Cu+2 and its surface‐bound alkaline phosphohydrolase was repressed and inhibited by inorganic phosphate, or removed by mutation, the breakdown products were still the only products of fermentation. Under these conditions, the third enzyme, a surface‐bound non‐repressible nucleotide phosphohydrolase was still active. It appears, at least in B. subtilis, that excretion is dependent upon breakdown by this enzyme and if hydrolysis does not occur, excretion of purine nucleotides is feedback inhibited by the resultant high intracellular IMP concentration. Corynebacterium glutamicum mutants, on the other hand, can excrete intact nucleotides, and direct fermentations for IMP, XMP, and GMP have been described. An examination of phosphohydrolases in a GMP‐producing culture revealed no extracellular or surface enzymes. Disruption of the cells resulted in liberation of cellular phosphohydrolase activity with a substrate specificity remarkably similar to the flavorenhancing properties of the 5′‐nucleotides. The order of decreasing susceptibility was GMP, IMP, XMP; AMP was not attacked.
Oxygen diffusion through zoogloeal flocs
Authors: Mueller James A. , Boyle William C. , Lightfoot Edwin N.
Published: December 2004

The mechanism of oxygen transfer through a pure culture floc of Zoogloea ramigera I‐16M has been described quantitatively. Oxygen uptake rates for both blended and nonblended floc particles indicated that, at a certain dissolved oxygen concentration, diffusion of oxygen through the floc matrix was the mechanism controlling the rate of oxygen utilization by the floc. This mechanism was quantitatively described by determining the oxygen diffusivity values for the floc. The diffusional distances of the floc particles along with the oxygen utilization rates of the floc were measured on floc grown under various conditions. Anoxic core equations were then used to calculate the oxygen diffusivity values for each experiment. These diffusivity values were then used to estimate the oxygen concentrations necessary in activated sludge plants.
In vitro synthesis of polyribonucleotides
Authors: Cherepak M. M. , Hansen R. W.
Published: December 2004

Polyribonucleotide: orthophosphate nucleotidyl transferase, commonly known as polynucleotide phosphorylase catalyzes the reversible polymerization of ribonucleoside diphosphates with the liberation of orthophosphate. The equilibrium constant is approximately 1.0. Although isolated from a variety of sources, the enzyme occurs essentially as two types: one which does not require a primer for reaction initiation and a second which does. A parallel study of an E. coli preparation representing the first type and an M. lysodeikticus preparation representing the second showed differences other than the primer requirement. Rates of polymerization were different as were the Kms. The E. coli preparation catalyzed the synthesis of polyguanylic acid while the M. lysodeikticus preparation did not although synthesis of hetoropolymers containing guanylic acid was catalyzed by the M. lysodeikticus enzyme. Use of repurified commercial substrates made the validity of some primer‐requirement experiments suspect. End group analysis of product polymers served only to raise questions concerning the reaction‐initiating compounds and the reaction mechanism. A study of hetero‐polymer synthesis showed not only that the rate of polymerization was different, from that of homopolymers but that uncompetitive inhibition rather than competitive inhibition occurred when two ribonucleoside diphosphates were present in the reaction mixture. Furthermore, the experiments showed a preferential uptake of one substrate over another and an “enrichment” which was constant. It has also been shown that RNA polymerase, a DNA‐RNA directed polymerase, can be used to synthesize polyribonucleotides if the appropriate template is provided.
Continuous flow cultures of a HeLa cell line as a basis for a steady supply of Rubella virus
Authors: Holmström Björn
Published: December 2004

A HeLa cell line was propagated in semicontinuous suspension culture, 85 liters final volume, and in continuous flow culture with a volume of 300 ml. or 5 liters in an autoclavable medium to which 8% calf serum had been added. A medium containing 0.1% Methocel and 2% calf serum was also tested. Maximum productivity was obtained at a dilution rate of 0.33 day−1 with a cell density of about 1.0 × 106 cells/ml. The same cell line was also infected with Rubella virus and the production of virus was followed at the 5‐liter cultivation level.
Slaframine: A parasympathomimetric from Rhizoctonia leguminicola
Authors: Aust S. D. , Broquist H. P. , Rinehart K. L.
Published: December 2004

An interesting cholinergic compound has been isolated from the fungus Rhizoctonia leguminicola grown on extracts of red clover hay. The compound was characterized as 1‐acetoxy‐8‐aminooctahydroindolizidine and given the name “slaframine.” It has been shown that slaframine is not the active compound but is converted to the active metabolite by liver microsomal enzymes. Physiological studies with slaframine point out that it is a potent stimulator of exocrine glands. In addition, its long duration of action and low toxicity suggest that it may have therapeutic value. Preliminary data suggest that slaframine is a potent stimulator of pancreatic activity, and its long duration of action results in a stimulation of protein synthesis by the gland.
Emetic material associated with Fusarium species in cereal grains and artificial media
Authors: Prentice Neville , Dickson A. D.
Published: December 2004

Substances which cause emesis in pigeons were extracted from corn (Zea mays) artificially inoculated with Fusarium graminearum and from liquid culture medium inoculated with F. moniliforme, F. roseum, F. poae, F. culmorum, and F. nivale. Emetic preparations were obtained also from infected wheat (Triticum aestivum L. em. Thell), (Hordeum vulgare L. em. Lam), and durum (Triticum durum Desf). Partial purification resulted from chromatography with columns of cellulose and DEAE cellulose and with thin layers of silica gel. Two active materials were obtained from liquid culture of F. moniliforme but only one from infected cereals. Emetic preparations from F. moniliforme and infected cereals contained a polypeptide as a minor component. Ultraviolet and infrared spectrums, elemental analyses, refractive indices, and amino acid composition of the emetic from corn and one of the emeties from liquid culture of F. moniliforme were similar but not identical. Attempts to crystalline these emetics and to characterize them were unsuccessful.
Input and volume distributions for continuous cultures
Authors: Grieves Robert B. , Kao Richard
Published: December 2004

An analysis is presented of the effects on substrate utilization and cell growth of varying the volume distribution of and the input distribution to a model continuous‐culture unit consisting of three stirred tanks. The model is used to establish the best volume and input distributions and to indicate the effects of mixing imperfections. The Michaelis‐Menten rate expression is utilized, including an endogenous respiration term, and results are presented on unique triaxial charts. Of the distributions considered, maximum substrate utilization is achieved with 60% of the total volume in the first stage, 20% in the second stage, and 20% in the third stage and with all of the input to the first stage. At a constant fractional input to the third stage; variation in the ratio of inputs to the first and second stages has virtually no effect, except in the case that a critical dilution is exceeded. At a constant input ratio to the first two stages, an increase in the fractional input to the third stage always decreases efficiency. Three stages, regardless of relative size, are always better than one. Except for endogenous respiration effects, cell growth parallels substrate utilization.
Production of fatty acids and lipid by a Candida sp. growing on a fraction of n‐alkanes predominating in tridecane
Authors: Ratledge Colin
Published: December 2004

A Candida sp. was grown on a fraction of n‐alkanes (dodecane 22%, tridecane 48%, tetradecane 28%) as sole carbon source. The growth rate was increased most markedly by using high concentrations of n‐alkanes (16.7% v/v). When grown in a 5 liter fermentor, the yeast reached its highest yield (60 g. of cell dry wt/l) with a concomitant high yield of fatty acids (21 g of fatty acids/l), by using a nitrogen‐deficient medium. To achieve good growth, it was essential to use an inoculum (1 part into 10) of rapidly growing cells and beneficial to increase the agitation rate gradually once growth had begun. After 108 hr maximum conversions of substrate to product were: 71.5% (w/w) for alkanes into cells and 24.8% (w/w) for alkanes into fatty acids. Of the, total fatty acids at the end of the fat‐accumulating phase of growth 54% were shorter in chain length than palmitic acid (C16H32O2). When grown on glucose, as sole carbon source, less than 2% of the total fatty acids were shorter than palmitic acid. When n‐alkanes were added to cells growing on glucose, short‐chain fatty acids (C10 to C14) were synthesized immediately, indicating a derepressed enzyme system for hydrocarbon assimilation and the absence of diauxie. The production of these acids was at the apparent sacrifice of linoleic acid synthesis. In spite of the high conversion ratios, it is concluded that it would be uneconomical to produce fatty acids, even expensive ones such as lauric acid, by microbial transformation of n‐alkanes.
Automatic analysis of gas exchange in microbial systems
Authors: Fiechter A. , Von Meyenburg K.
Published: December 2004

An automatically working test arrangement for the permanent analysis of O2 and CO2 in microbiological cultures is described. The measuring principle is based on the paramagnetic properties of oxygen and on the absorption of infrared by carbon dioxide. The preparation of the gas for measuring and the correction of the recording are indicated. The formula of correction was programmed and the values were calculated for a range of 3%. The routine correction of analysis values is done with a nomogram established on the basis of these individual values. The advantages of the described test arrangement are illustrated by two examples of growth experiments on Saccharomyces cerevisiae.
Virus particle quantitation and its application to virus–host cell interactions
Authors: Galasso G. J.
Published: December 2004

Virus quantitation is discussed stressing the discrepancy between the biological titer and the physical virus particle count. When both these techniques are used in conjunction, one can more realistically catalog viral properties. The merits of this technique are exemplified in a study of the growth kinetics and properties of vesicular stomatitis virus in tissue culture.
Application of a multiple surface tissue culture propagator for the production of cell monolayers, virus, and biochemicals
Authors: Schleicher Joseph B. , Weiss Ronald E.
Published: December 2004

A new concept of tissue culture equipment and procedures was developed for the mass‐scale growth of several types of animal tissue cells in monolayers on multiple glass surfaces. Continuous, cell lines, primary and diploid cell strains were grown in this equipment. Cells studied include primary bovine kidney, human diploid WI‐38, human foreskin, and mouse CCL1 cells. Photomicrographic comparisons of cells grown by these techniques indicate they are morphologically identical to tissue culture cells grown in glass bottles or tubes. The growth of the tissue culture cells in the propagator was monitored by carbohydrate Utilization and acid production. Large‐scale production of viruses and biochemicals on cells grown in the multiple‐plate tissue culture propagator was accomplished. Virus titers were equal to those obtained from conventional bottle or tube cultures for several strains of influenza, parainfluenza, and respiratory syneytial viruses. High‐titred mouse interferon was also produced in this system. In addition to tissue culture cell production, Eaton agent, Mycoplasma pneumoniae was grown on the multiple glass surfaces on a mass scale.
Equipment for the recovery of precipitates from tubular centrifuges
Authors: Miller G. , Mizrahi A. , Shawit G.
Published: December 2004

Equipment has been developed for the recovery of precipitates from rotors of industrial tubular centrifuges. A double piston is described for nonaseptic discharge of precipitates through the outlet holes of the clarifier rotor. For the aseptic resuspension or dissolving of valuable precipitates a closed‐circulation system has been developed, which is applied without opening of the clarifier rotor.