bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geosmin, an earthy‐smelling substance isolated from actinomycetes
Authors: Gerber Nancy N. 
Published: December 2004

AbstractGeosmin, an earthy smelling substance, has been obtained from several actinomycetes in addition to those previously reported. On the basis of the NMR and mass spectra of geosmin and its acid transformation product, argosmin, tentative partial structures have been proposed for both.
A method for the control of the dissolved oxygen tension in microbial cultures
Authors: Flynn D. S. , Lilly M. D. 
Published: December 2004

AbstractA method for the control of dissolved oxygen tension in growing microbial cultures is described. The apparatus consists of a motor‐driven air sparge pipe which may be lowered or raised to give a variable point of entry of the air stream into the culture liquid and hence a variable gas dispersion and gas–liquid contact time. Control of the sparge pipe position is by means of a feedback control loop consisting of a dissolved oxygen probe, an on/off controller, and a reversing electric motor which drives the sparge pipe. The difficulty presented by the relatively slow response of the oxygen probe has been overcome by incorporating an adjustable rate of control action.
A mathematical model for the batch reactor kinetics of algae growth
Authors: Ragonese Francis P. , Williams John A. 
Published: December 2004

AbstractA mathematical model based on the Einstein law of photochemical equivalence is proposed to describe the batch growth of unicellular algae. The model was applied in an integrated form to cell concentration versus growth time data taken over an extended range of cell concentrations which include both the regions of “exponential” and “linear” growth. It is shown that a certain function of cell concentration contained in the integrated form of the model is linearly dependent on the growth time over both the “exponential” and “linear” growth regions.
A mathematical model for the continuous culture of microorganisms utilizing inhibitory substrates
Authors: Andrews John F. 
Published: December 2004

AbstractA mathematical model is presented for both batch and continuous cultures of microorganisms utilizing inhibitory substrates. The key feature of the model is the use of a inhibition function to relate substrate concentration and specific growth rate. Simulation studies show that the primary result of inhibition by substrate in a batch culture is an increase in the lag time whereas in continuous culture inhibition by substrate may result in process instability. The model should be of value in investigations of the stability of biological processes used for the treatment of certain industrial wastes such as those containing phenols, thiocyanates, nitrates, ammonia, volatile acids, etc., which are known to be inhibitory to many of the organisms metabolizing them.
Kinetics of product inhibition in alcohol fermentation
Authors: Aiba S. , Shoda M. , Nagatani M. 
Published: December 2004

AbstractThe inhibitory effect of ethanol concentration p in a medium on the specific rates of growth μ and ethanol production ν of a specific strain of baker's yeast was studied in a chemostat, where except for ethanol as the product, only the concentration of glucose S was controlled to limit the metabolic activity of the yeast. This was designed to supplement the previous findings from the batch experiment, in which ethanol was added artificially and no substrate components were limiting the metabolism of the same yeast, that μ = μ0e and ν = ν0e, where k1 and k2 are empirical constants and subscript the 0 denotes respective values at p = 0. The effects of p on the values of μ and ν were confirmed by the Lineweaver‐Burk plot to belong to noncompetitive inhibition. The formulas here for μ and ν as affected by p, if extrapolated to the case of no limiting substrates, were in good agreement in respective forms with those derived previously from the batch experiment, though the values of corresponding coefficients in these formulas were different. The differential equations for μ and ν as functions of both p and S and, in addition for the rate of glucose consumption as correlated by the yield factors either with the cell growth rate or the rate of ethanol production, were solved properly with a digital computer. A kinetic, pattern calculated so far was discussed with reference to the data obtained in the batch experiment and those relevant to actual “sake” brewing.
Investigation of some methods for increasing the digestibility in vitro of microalgae
Authors: Hedenskog Gudmund , Enebo Lennart , Vendlová Jitka , Prokeš Bohumír 
Published: December 2004

AbstractIn order to increase the availability of the cell bound protein in Scenedesmus algae, mechanical, enzymatic, and chemical methods of degrading the cell wall structure were investigated.Mechanical treatment involved the use of a ball‐mill. The algae suspension together with glass beads was milled in a water‐cooled chamber equipped with rotating disks. The enzyme tested was a cellulolytic enzyme (Meicelase) and the chemical employed was hydrogen peroxide.In the ball‐mill experiments a complete disintegration was achieved ina disintegrator, working with batches. Trails wwere also performed with a continuous disintegrator and the depedence of disintegration on bead size and flow rate was studied. The disintegration determined by microscropic cell count was compared to the increase of the pepsin digestibility.The meicelase treatment caused a slight increase of the pepsin digestibility, as measured after 3 hr pepsin incubation. No increase of the pepsin disgestibility could be detected with hydrogen peroxide treatment.After the ball‐mill disintegration 95% of contaminating bacteria were killed and yields of extractable proteins were higher. The capacity of availble continuous ball‐mills is such that they could be used on a pilot‐plant scale and the energy cost of disintegration would be of the same magnitude as that of separation.
Studies on the relationship between specific growth rate and concentration of nitrogen source for heterogeneous microbial populations of sewage origin
Authors: Goel K. C. , Gaudy A. F. 
Published: December 2004

AbstractBatch experiments were run using heterogeneous populations to determine whether a hyperbolic equation of the type suggested by Monod could be used to depict the relation between specific growth rate, μ, and NH3‐N concentration when ammonia N was the growth‐limiting nutrient. The heterogeneous populations employed were developed from sewage seed grown on glucose at various levels of nitrogen and various dilution rates in completely mixed continuous flow reactors. It was found that the hyperbolic function could be used. Values of μm in the range of 0.4–0.7 hr−1 were observed, and values of Ks, in general, ranged from 1.5 to 4.0 mg/l. Variation in the values of these growth “constants” did not follow any discernible pattern related to past growth history (i.e., COD:N ratio or dilution rate at which the cells were previously grown).
Regulation of nitrogen levels for heterogeneous populations of sewage origin grown in completely mixed reactors
Authors: Goel K. C. , Gaudy A. F. 
Published: December 2004

AbstractHeterogeneous populations of sewage origin were grown continuously at, dilution rates from 1/12 hr−1 to dilute‐out (1/1 hr−1) using glucose (1000 mg/l) as carbon source and three concentrations of NH3‐N as the nitrogen source (COD:N = 70:1, 40:1, and 25:1). The effects of nitrogen level and growth rate (dilution rate) on substrate removal, biological solids production, cellular carbohydrate and protein, and NH‐N in the effluent were examined. It was found that the optimum level of nitrogen supplementation for the synthetic nitrogen‐deficient waste employed should not be based solely on the desired effluent quality with respect to COD removal but should include due consideration of reactor detention time (or dilution rate) and the allowable (or desirable) level of nitrogen leakage in the effluent.
Methylcellulose effect on cell proliferation and glucose utilization in chemically defined medium in large stationary cultures
Authors: Bryant Jay C. 
Published: December 2004

AbstractThree different established strains of mammalian cells were grown in chemically defined medium in large cultures. The degree of proliferation of cells of an established strain from human skin in large stationary cultures was significantly greater in the presence of methylcellulose (medium NCTC 135M) than in its absence (medium NCTC 135). The relatively fragile cells of a derivative of monkey kidney LLCMK2 strain were carried in large stationary cultures through 11 transfer generations during 152 days. The presence of methylcellulose was associated with higher cell population levels, proliferation rates, and cell viability. Cells of this strain utilized glucose at an extremely high rate; during two representative periods the rate averaged 1.2 mg/106 cells/day in cultures on medium 135M and 1.9 mg in medium 135.In a 53‐day experiment with mouse fibroblast 2071‐L cells, the cells in suspension culture during the first 28 days went through the normal lag, logarithmic plateau, and initial decline phases in medium 135M, and then were transferred to large stationary cultures, where they proliferated for 7 days at uniformly high rates in both medium 135 and medium 135M. It appeared that cells of strain 2071‐L in such stationary cultures had no need for Methocel as a protective agent. Glucose utilization rates while these cells were carried in large stationary cultures averaged 2–4 times the rates while they were in suspension cultures: about 0.8 and 0.2 mg/106 cells/day, repectively.
The conversion of benzyl penicillin to 6‐aminopenieillanie acid using an insoluble derivative of penieillin amidase
Authors: Self D. A. , Kay G. , Lilly M. D. , Dunnill P. 
Published: December 2004

AbstractPenicillin amidase was extracted from Escherichia coli ATCC 9637, grown on phenylacetic, acid and glutamate, and purified by fractional ion with streptomycin sulphate, ammonium sulphate and polyethylene glycol, followed by chromatography on DEAE–cellulose. The purification factor was 100–200 × and the overall yield was about 115%. The enzyme was chemically attached to derivatives of cellulose and the kinetics of these insolubilized penicillin amidase preparations was investigated.
Isolation of a cyclitol antibiotic: 2,3,4,5‐tetrahydroxycyclohexanemethanol
Authors: Miller T. W. , Arison B. H. , Albers‐Schonberg G. 
Published: December 2004

AbstractThe isolation and structure determination of a new microbial product, (+)‐ (123/45)‐2,3,4,5‐tetrahydroxy‐1‐cyclohexanemethanol is described. This product was detected in the fermentation broth of a newly isolated actinomycete by its antibacterial activity. A novel isolation method was developed and crystalline product was obtained in good yield. The structure was determined by spectroscopic examination of the product and its acetyl and trimethylsilyl derivatives. The racemic form of this compound had already been synthezised by G. E. McCasland et. al., as analog of galactose.
Dynamic behavior of a complete‐mixing activated sludge system
Authors: Chu George C. Y. , Erickson L. E. , Fan L. T. 
Published: December 2004

AbstractThe dynamic behavior of a laboratory‐scale activated sludge biological waste treatment process with recycle and wasting of sludge was investigated by subjecting the system to step changes in the influent waste concentration, the recycle flow rate, or the sludge wasting rate. The dynamic behavior of the system was examined by measuring adenosine triphosphate (ATP) in addition to dissolved chemical oxygen demand (COD) and cell dry weight in the aeration tank. Cell dry weight of the recyle flow and effluent COD were also measured.Analysis of the results and estimation of time constants assuming first order responses showed that the time constants characterizing the dynamic responses of the sludge were directly related to the sludge mean residence time. The time constants estimated from dissolved COD measurements were of the same order of magnitude as the fluid residence time in the aeration tank. The ATP transient response was frequently different from that of the cell dry weight in the aeration tank.
Maintaining perpetual synchrony in HeLa S3 culture
Authors: Thilly W. G. , Nowak T. S. , Wogan G. N. 
Published: December 2004

AbstractHeLa S3 cells in suspension culture are resynchronized in each successive generation by exposure to 0.25mM thymidine. The resynchronization approach appears to be superior to single‐ and double‐block techniques because the period of effective inhibition of DNA synthesis is significantly shortened. Gram quantities of highly synchronous viable cells have been produced on a daily basis.
The rheology of mycelial broths
Authors: Roels J. A. , Van Den Berg J. , Voncken R. M. 
Published: December 2004

AbstractAn experimental investigation on the rheology of penicillin broths was undertaken in order to obtain more understanding of this important aspect of the fermentation process. The measuring technique consisted in observation of the torque exerted upon a rotating turbine impeller. The experimental data were interpreted in terms of a model which basically is a synthesis of a known relationship for the rheological behavior of printing ink (Casson equation) and some considerations analogous to the rheological description of polymer solutions (excluded volume concept). One of the key variables in the model is a morphology factor, which can be used for a quantitative description of mycelial morphology. The value of the morphology factor can be determined experimentally by a simple viscosity measurement in combination with a mycelial dry weight determination. There are strong indications that the model may be applicable to mycelial broths other than those of penicillin.
Experimental optimization of a step aeration waste treatment process
Authors: Chu George C. Y. , Erickson L. E. , Fan L. T. 
Published: December 2004

AbstractEvolutionary operation (EVOP) was used to experimentally investigate the optimum steady state operating conditions for a step aeration activated sludge waste treatment process. A laboratory scale two tank step aeration activated sludge unit with fixed total volume, total influent flow rate, recycle flow rate, and sludge wasting rate was employed. The volume ratio and flow rate ratio which minimized effluent chemical oxygen demand were determined. The results indicate that EVOP is a useful technique for improving the performance of biological processes.
Mechanical disintegration of microorganisms in an industrial homogenizer
Authors: Mogren Hårkan , Lindblom Marianne , Hedenskog Gudmund 
Published: December 2004

AbstractDisintegration of microorganisms in a continuously working industrial homogenizer has been studied. The homogenizer consists of rotating discs in a cylinder filled with glass beads. Different parameters for disintegration of baker's yeast were investigated. The disintegration process is a first‐order reaction and it is influenced by the flow rate of the suspension and by the agitator speed. At a flow rate of 200 liters/hr about 85% of the yeast cells can be disrupted in a single pass through the disintegrator. This type of disintegrator can be used for disruption of cells in order to produce single‐cell protein, active enzymes and other valuable cell components.
Immobilized enzyme reaction stability: Attrition of the support material
Authors: Regan D. L. , Dunnill P. , Lilly M. D. 
Published: December 2004

AbstractOne of the main reasons for immobilizing an enzyme is to enable its reuse, or continuous use, in a reactor. Consequently immobilized enzyme stability is an important factor in enzyme reactor design. The performance of the reactor will decrease if during operation the support material disintegrates into smaller particles that pass out of the reactor system.When β‐galactosidase is immobilized by covalent attachment to AE‐cellulose, the smaller particles have a higher activity. After subjection of the immobilized enxyme to a shear stress the average particle size decreases and the total enzymic activity increases. A loss of small particles from the reactor, although constituting a small weight percent loss of support, will result in a disproportionately large loss in activity. The relevance of these observations to reactor performance is discussed.
A generalized mathematical model for the growth kinetics of Saccharomyces cerevisiae with experimental determination of parameters
Authors: Peringer P. , Blachere H. , Corrieu G. , Lane A. G. 
Published: December 2004

AbstractA general model of the kinetics of microbial growth has been developed involving the kinetics of incorporation of substrate into biomass and the maintenance energy requirements.Results obtained from batch cultures of the yeast Saccharomyces cerevisiae growing in synthetic media at pH 5.1 and 30°C permitted all biological parameters in the model to be calculated.Values obtained for these parameters were: maximum specific glucose uptake rate (μSm), 2.08 g/g biomass/hr; apparent Michaelis constant for glucose (KS), 0.1 g/liter (5.5 × 10−4M) apparent Michaelis constant for oxygen (KL), 1.4% O2 (3.2 × 10−6 M) quantitative index of the Pasteur effect (b), 4.9 × 10−4%−1 O2 (207 M −1). Under conditions of strongly substrate‐repressed respiration the values obtained for YATP and P/O were constant over the course of the exponential phase of growth (YATP = 10.4 g biomass/mole ATP; P/O = 3 moles ATP/atom 0). Mass balances for aerobic and anaerobic cultures confirmed the results obtained form the generalized model. Results presented suggested the operation of a mechanism for regulating energy‐yielding metabolism which involved an equilibrium between the systems of oxidative phosphorylation and dephosphorylation and was dependent upon the level of catbolite repression.
Immobilization of enzymes by radiopolymerization of acrylamide
Authors: Kawashima Koji , Umeda Keiji 
Published: December 2004

AbstractA new and simple method for immobilization of enzymes by the aerobic radio‐polymerization of acrylamide was developed. Irradiation treatment of acrylamide in the frozen state produces a spongy immobilized enzyme membrane without the addition of carriers. Aerobic polymerization yields of acrylamide in the frozen state were increased by the addition of starch and also by lyophilization.Glucose oxidase (activity recovery was 12.3–33.7%), invertase (69.2%), D‐amono acid oxidase (25.0–70.5%), aminoacylase (39.2–43.7%), mold α‐amylase (18.0%), malt β‐amylase (4.1%), glucoamylase (6.5%), alkaline protease (5.3%), and neutral protease (10.5%) were immobilized by this method. Invertase entrapped by this method had a wider optium pH range and was active at higher temperatures.
Single cell proteins from cellulosic wastes
Authors: Bellamy W. Dexter 
Published: December 2004

AbstractConventional sources of protein cannot meet the present or projected needs for human consumption. Single cell proteins from fermentation of petroleum and cellulosic wastes are likely sources of additional protein. The volume of cellulosic wastes is sufficient to supply all additional protein needs on a continuing basis for cellulose is a renewable resource. Both mesophilic and thermophilic microorganisms utilize cellulose at reasonable rates. Biodegradation of lignin and lignin–cellulose complexes constitutes a major obstacle to commercial utilization of cellulosic wastes. Thermophilic actinomyces appear to be the most effective organisms for single cell protein production from cellulosic wastes.
Simultaneously immobilized glucose oxidase and catalase in controlled‐pore titania
Authors: Messing Ralph A. 
Published: December 2004

AbstractThe immobilization of glucose oxidase and catalase by adsorption within the pores of controlled‐pore titania has yielded a remarkably stable enzyme system. Catalase apparently acts as both a stabilizer and an activator for glucose oxidase within the pores of this material. Hydrogen peroxide concentrations and flow rates have a marked effect upon the apparent activity of the immobilized enzyme system. The carrier parameters were varied to obtain optimum loading and stability information.
CO2 mass balance in a suspension of algae cultivated in the neutral pH region of the suspension on an open cultivation surface
Authors: Lívanský K. , Prokeš B. 
Published: December 2004

AbstractThe CO2 mass balance for a suspension of algae cultivated in the region of neutral pH of the suspension on an open cultivation surface with a flowing suspension was assessed. From this balance an analytical expression for the course of free CO2 dissolved in the suspension along the flow of the suspension is obtained. Relations for the rate of CO2 decrease in the suspension and the utilization of CO2 supplied to the cultivation surface are derived.
Pilot scale affinity chromatography: Purification of β‐galactosidase
Authors: Robinson P. J. , Wheatley M. A. , Janson J.‐C. , Dunnill P. , Lilly M. D. 
Published: December 2004

Abstractβ‐Galactosidase has been purified from an ammonium sulfate precipitate of E. coli strain ML308 by biospecific adsorption on a column of agarose gel substituted with p‐aminophenyl‐β‐D‐thiogalactopyranoside. The system described using a 1.8 liter column has a useful processing capacity of 3.8 × 106 units of β‐galactosidase per 2 hr cycle. This corresponds to about 5 g of pure enzyme. An electromechanical timing device operates a set of six solenoid valves and carries out a preset program consisting of sample application, washing, and elation operations.
Large scale enzymatic synthesis of nucleoside‐5′‐monophosphates using a phosphotransferase from carrots
Authors: Marutzky R. , Peterssen‐Borstel H. , Flossdorf J. , Kula M.‐R. 
Published: December 2004

AbstractThe enzymatic synthesis of nucleoside‐5′‐monophosphates from purineriboside, 6‐mercapto‐purine riboside, 6‐methylmercapto‐purine riboside, 6‐chloro‐purine riboside, tubercidin, 8‐aza‐adenosine, and 3′‐deoxy‐adenosine is described in gram scale. The synthesis is catalyzed by a phosphotransferase from carrots and uses phenylphosphate as phosphate donor. The reaction products are purified on QAE‐Sephadex A25 columns. The large scale preparation of the enzyme is also reported.
Properties of ribulose diphosphate carboxylase immobilized on porous glass
Authors: Shapira Jacob , Hanson Carl L. , Lyding Judith M. , Reilly Peter J. 
Published: December 2004

AbstractRibulose‐1,5‐diphosphate carboxylase from spinach has been bound to arylamine porous glass with a diazo linkage and to alklamine porous glass with glutaraldehyde. Stability at elevated temperatures and responses to changes of pH and ribulose‐1,5‐diphosphate, Mg2+, and dithiothreitol concentrations were not significantly different from the soluble enzyme, though stability at 4°C was somewhat improved.
Grazing of ciliates on blue–green algae: Effects of ciliate encystment and related phenomena
Authors: Bader F. G. , Tsuchiya H. M. , Fredrickson A. G. 
Published: December 2004

AbstractGrazing of the ciliate Colpoda steinii on the blue–green alga Anacystis nidulans has been studied in batch and chemostat type laboratory cultures. Growth of the populations, grazing of the ciliates on the algae, hydrodynamic washout of the populations (in chemostat cultures), encystment of Colpoda, and transfer of cysts from the liquid culture to the vessel wall and their attachment thereto were all found to have significant effects on the dynamics of this system. In addition, reinoculation of the liquid with ciliates excysted from the wall and with algae detached from the wall may be important. The interaction of all of these processes produces quite complex dynamical phenomena which at present cannot be predicted by a model. The results obtained differ from those found earlier for feeding of ciliates or slime mold amoebas on bacteria in that steady states of coexistence, rather than sustained oscillations, were exhibited by the present system.