bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of an exchange filtration technique to obtain synchronous sporulation in an extended batch fermentation
Authors: Watson D. C. , Berry D. R. 
Published: December 2004

AbstractA fermentor system with an external filtration loop has been developed to control the growth and sporulation of yeast in a single vessel. Excess growth medium, instead of being removed by centrifugation, is removed by filtration and replaced with acetate sporulation medium. The technique did give 80% sporulation after 20 hr, greatly improving the rate and degree of synchrony of sporulation and it also eliminated the contamination hazard of the conventional harvest technique, centrifugation, and resuspension of vegetative cells in sporulation medium. Furthermore it permits proper control of the environmental conditions throughout the growth, exchange, and sporulation phase. In this technique 100% recycle of biomass is achieved without any packing of the cells on the filter. This technique has wide application in the study of industrial fermentation that involves microbial differentiation such as the production of ergot alkaloids, bacitracin, and cephalosporin.
Carbon dioxide fixation by immobilized chloroplasts
Authors: Karube Isao , Aizawa Kaoru , Ikeda Sakuji , Suzuki Shuichi 
Published: December 2004

AbstractChloroplasts of chinese mustard (Brassica campestris L.) were immobilized in polyacrylamide gel. A 8% polymer concentration was suitable for the immobilization. The activity of the carbon dioxide fixation of immobilized chloroplasts was 65% of that of free chloroplasts. The optimum conditions for the carbon dioxide fixation of immobilized chloroplasts were similar to that of native chloroplasts. However, immobilized chloroplasts were more stable under alkaline conditions and high temperatures than native chloroplasts. Light penetration of the gel was not a limiting parameter of the carbon dioxide fixation. The lifetime of immobilized chloroplasts was three times longer than that of free chloroplasts. 3‐Phosphoglyceraldehyde and other compounds were produced continuously by immobilized chloroplasts.
Penicillin G production by immobilized whole cells of Penicillium chrysogenum
Authors: Morikawa Yasushi , Karube Isao , Suzuki Shuichi 
Published: December 2004

AbstractPenicillium chrysogenum was immobilized in polyacrylamide gel prepared from 5% acrylamide monomers (85% acrylamide and 15% N,N′‐methylene bisacrylamide). Penicillin produced from glucose by the immobilized mycelium was 17% of that produced by washed mycelium. However, the activity of penicillin production of the washed mycelium decreased with repeated use. On the other hand, the activity of the immobilized mycelium increased initially and decreased gradually with repeated use. The rate of oxygen uptake of the immobilized mycelium was about 30% of that of the washed mycelium. The immobilized mycelium required oxygen for the production of penicillin.
Production of cellulases by Trichoderma reesei QM 9414 in fed‐batch and continuous‐flow culture with cell recycle
Authors: Ghose T. K. , Sahai Vikram 
Published: December 2004

AbstractThe scope in improving enzyme productivities from the cellulose fermentation process is examined in laboratory‐scale fermentors. The maximum productivity (30 IU/liter hr) is attained in a continuous‐culture process with cell recycle using modified medium containing 0.5% cellulose. Optimum dilution rate and recycle ratio are determined as 0.025 hr−1 and 1.2, respectively, for the process. The system is analyzed and steady‐state equations for predicting enzyme protein concentrations in the fermentor are developed. In fed‐batch cultures, slow addition of cellulose at high concentrations can improve enzyme productivity by as much as 33% over a batch process. The scope and results of using modified medium for cellulase production are also presented.
Association of β‐glucosidase with intact cells of Thermoactinomyces
Authors: Hägerdal Bärbel , Harris Harriet , Pye E. Kendall 
Published: December 2004

AbstractThe location of the β‐glucosidase activity in a whole culture broth of the thermophilic organism Thermoactinomyces has been studied. Little β‐glucosidase activity was found in the culture filtrate, while the culture solids contained the major part of the activity of the whole culture broth. The activity does not appear to be adsorbed to the culture solids; rather there is evidence that it is an intracellular soluble enzyme(s). The pH and temperature optima for a crude β‐glucosidase preparation were determined to be pH 6.5 and 50–55°C. Enzyme activity studies indicate that the same enzyme(s) accounts for the β‐glucosidase and the cellobiase activities. The validity of using the filter paper activity of culture filtrates from Thermoactinomyces to predict the total saccharification of cellulosic materials to glucose is discussed.
Light‐induced enzyme system leading to pigmentation
Authors: Kuan K. , Lee Y. Y. , Tebbetts L. , Melius P. 
Published: December 2004

Abstractα‐Chymotrypsin was light sensitized by acylating with cis‐cinnamoyl ester, a substrate interconvertible to the trans form by ultraviolet (UV) light. The degree of acylation by this method was complete leaving no residual activity of the enzyme. Upon UV irradiation the inhibited enzyme regained about 70% of its original activity, thereby adding light‐sensitiveness to the proteolytic enzyme. In seeking a photographic application of the light‐sensitized enzyme, a pigmenting enzyme was incorporated with it. The coupled enzyme system was shown to exhibit a light signal in the form of dark pigment slurry.
Immobilization of enzymes on activated carbon: Selection and preparation of the carbon support
Authors: Cho Y. K. , Bailey J. E. 
Published: December 2004

AbstractBased upon its superior catalytic activity for H2O2 decomposition, a bituminous coal‐based activated carbon was selected for investigations of pretreatment and enzyme immobilization methods. Pretreatments considered include acid washing, exposure to strong oxidizing agents, contact with concentrated peroxide solutions, nitration and amination, isothiocyanate derivatization, silanization, and stearic acid coating. Effects of these pretreatments on morphology and trace‐metal content of the carbon pellets have been studied using scanning electron microscopy and dispersive analysis of x rays. Immobilization of glucoamylase by adsorption, glutaraldehyde crosslinking, and covalent attachment to carbon activated by water‐soluble diimide or diazotization have been examined. These different enzyme–carbon catalysts have been characterized by their enzyme loading, enzyme activity, catalytic activity for H2O2 decomposition, or combinations of these measures of performance.
Mathematical model of cell growth and phosphatase biosynthesis in Saccharomyces carlsbergensis under phosphate limitation
Authors: Toda K. , Yabe I. 
Published: December 2004

AbstractThe rate kinetics of growth and acid phosphatase formation in the batch culture of Saccharomyces carlsbergensis LAM 1068 was studied under varying degrees of phosphate limitation. The mathematical model that was developed is concerned with the time lag for exponential growth, the biphasic growth on a substrate (glucose) and its product (ethanol), sustained growth on conservative phosphate, and the derepression of acid phosphatase. The numerical calculations using appropriate parametric constants successfully described the variation in the cell mass, glucose, ethanol, and inorganic phosphate concentrations, and the enzyme activity of acid phosphatase during aerobic growth of S. carlsbergensis under five different conditions of phosphate starvation. A simulation study revealed that the optimum initial phosphate concentration in the medium giving a high productivity of acid phosphate was 2.0 mg phosphorus/g glucose liter.
Solid‐substrate fermentation of alfalfa for enhanced protein recovery
Authors: Bajracharya Rupak , Mudgett Richard E. 
Published: December 2004

AbstractSolid‐substrate fermentations for extraction of protein from pressed alfalfa residues with Aspergillus sp. QM 9994 aspergillus niger QM 877, and Rhizopus nigricans QM 387 were conducted in shake flasks. Upon reimbibing and second pressing, total protein recovery from alfalfa was increased from 47.2% for control samples and up to 64.5% for fermented samples. Analysis of juice from fermented samples indicated the presence of cellulase as well as pectinase activities. Dialysis cultures of cellulase‐producing fungi showed that total biomass production and solids consumption were much higher than those of a mutant strain lacking the ability to produce cellulase, indicating significant utilization of cellulosic materials in alfalfa. The biomass yields in the former case ranged from 39–47% based on total solids consumption. Since some of the cellulosic and other carbohydrate constituents in alfalfa may be converted into fungal protein, final alfalfa residues following protein extraction in a commercial process would be less bulky for storage and handing and would be more digestible as a nonruminant animal feed.
Utilization of mass–energy balance regularities in the analysis of continuous‐culture data
Authors: Erickson L. E. , Minkevich I. G. , Eroshin V. K. 
Published: December 2004

AbstractMaterial and energy balances for continuous‐culture processes are described based on the facts that the heat of reaction per electron transferred to oxygen for a wide variety of organic molecules, the number of available electrons per carbon atom in biomass, and the weight fraction carbon in biomass are relatively constant. Energy requirements for growth and maintenance are investigated and related to the biomass energetic yield. The consistency of experimental data is examined using material and energy balances and the regularities identified above. When extracellular products are absent, the consistency of yield models containing separate terms for growth and maintenance may be investigated using organic substrate consumption, biomass production, oxygen consumption (or heat evolution), and carbon dioxide evolution rate data for a series of dilution rates. The consistency of continuous‐culture data in the published literature is examined.
Removal of diacetyl from beer by adsorbants and diacetyl reductase
Authors: Gupta K. G. , Jain A. K. , Dhawan Surinder 
Published: December 2004

AbstractRemoval of diacetyl from beer with adsorbants like cellulose, silica gel, activated charcoal, calcium phosphate gel, anion‐ and cation‐exchange resins, and silicylic acid black soil bed (SABSB) was attempted in comparison with the enzyme diacetyl reductase (EC 1.1.1.5). Diacetyl could be removed from beer by the adsorbants but they had undesirable effect on the beer quality such as color, pH, and alcohol levels. These adverse effects were not observed with the use of diacetyl reductase. The results favor the enzymatic removal of diacetyl from beer as a superior approach.
Large‐scale isolation of equine liver alcohol dehydrogenase on a blue agarose gel
Authors: Roy S. K. , Nishikawa A. H. 
Published: December 2004

AbstractEquine liver alcohol dehydrogenase (EC 1.1.1.1) has been purified by a new scheme using a blue agarose gel (Blue Sepharose) as an affinity sorbent. Starting amounts of 0.6 to 10 kg liver have been processed to enzyme possessing 1.5 U/mg average specific activity, in about three to four days. Some parameters concerning adsorption of enzyme to the blue gel as well as recovery therefrom have been explored.
Assimilation efficiency and energy contents of prototrophic bacteria
Authors: Ho K. P. , Payne W. J. 
Published: December 2004

AbstractWhen the assimilation efficiency in batch culture of a variety of heterotrophic bacteria was tested in media containing progressively smaller concentrations of carbon substrate, two groups emerged. Those in the first group assimilated carbon progressively more efficiently as the initial concentration in the culture medium was lowered below 2 mg C/ml; some displaying efficiencies exceeding 80%. Those in the second group assimilated carbon at rates that changed little, if at all, with changes in the initial concentrations of carbon substrate. Members of the second group differed from the first in their metabolic versatility as evidenced by the ability of each to catabolize hydrocarbons. The energy content (heat of combustion) of the cells of the species tested varied little with changes in cultured conditions, and values for all fell close to the average for bacteria (5411 cal/g ash‐free dry wt). In continuous aerobic culture on glucose‐minimal medium, the carbon assimilation and energy assimilation efficiencies were simultaneously maximal for Enterobacter aerogenes when the input carbon concentration was 0.2004 mg/ml and the dilution rate was 0.57. An equation for predicting heat of combustion of cells from knowledge of their C,H,N, and O ratios was devised and tested. Precision ranged from +6% to −16%.
Maximization of Candida utilis cytochromes by pulse additions of ethanol to continuous cultures
Authors: Cail R. , Rickard P. A. D. , Rogers P. L. 
Published: December 2004

AbstractCandida utilis was grown with glucose as growth‐limiting carbon source in batch culture, steady‐state continuous culture, and non‐steady‐state continuous culture. High cytochrome concentrations were routinely recorded in cells harvested in the latter stages of batch culture. They were occasionally recorded in cells from imprecisely controlled steady‐state cultures, but precise control of the steady‐state dissolved oxygen tension stabilized the cytochromes at relatively low levels. Controlled non‐steady‐state continuous cultures, imposed by pulse additions of ethanol, routinely produced cells with high cytochrome concentrations. A mechanism is proposed whereby maintenance of cytochrome derepression in continuous culture is dependent upon indefinitely prolonging an “overshoot” response in gene expression.
Enzyme immobilization by radiation‐induced polymerization of 2‐hydroxyethyl methacrylate at low temperatures
Authors: Kaetsu Isao , Kumakura Minoru , Yoshida Masaru 
Published: December 2004

AbstractEnzyme immobilization by radiation‐induced polymerization of hydrophilic glass forming monomers, such as 2‐hydroxyethyl methacrylate, was studied. Enzyme radiation damage could be sufficiently retarded at low temperatures. The immobilized enzyme activity yield was markedly higher at low temperature than at higher temperature polymerization. At low temperatures the polymerized composite had a porous structure owing to ice crystallization which depends on the monomer concentration. It was deduced that the enzyme was partially trapped on the polymer surface, partially isolated in the pore, and partially occluded inside the polymer matrix. A decrease in activity caused by enzyme leakage was observed with repeated use in enzyme reactions where the composites had a large porosity. The activity yield showed a maximum at certain optimum porosities, i.e., at optimum monomer concentrations. Continuous enzyme reaction was preferably carried out using immobilized enzyme columns.
Continuous production of NADP by immobilized Brevibacterium ammoniagenes cells
Authors: Murata Kousaku , Kato Jyoji , Chibata Ichiro 
Published: December 2004

AbstractWhole cells of Brevibacterium ammoniagenes IAM 1645 having the polyphosphate NAD‐kinase were successfully immobilized in a polyacrylamide gel lattice. The immobilized cells were activated by treatment with organic solvents or detergents. The pH optimum of the immobilized cells for the production of NADP was 7.0, and divalent metal ions were required to maintain the elevated activity of polyphosphate NAD‐kinase. Highly pure NADP was continuously produced in high yield by the immobilized cell column. The half‐life of this column was about eight days.
Fractionation of the proteolytic and amylolytic complex enzyme system of Streptomyces aureofaciens and some properties of fractions
Authors: Laluce Cecilia , Molinari Rubens 
Published: December 2004

AbstractThe Streptomyces aureofaciens extracellular proteolytic system was split into four fractions by carboxymethylcellulose (CMC) column chromatography giving three purely caseinolytic fractions and one fraction active toward both starch and casein. The first caseinolytic and amylolytic fraction was further fractionated by DEAE‐Sephadex A‐50 chromatography into one purely amylolytic fraction and another showing both activities, was refractioned into four new fractions by DEAE‐cellulose chromatography. These fractions were found to be heterogeneous by polyacrylamide gel electrophoresis, three of them acted on both starch and casein and a fourth was only caseinolytic. The second CMC fraction was further purified by CMC rechromatography to an homogeneous fraction that hydrolyzes carboxypeptidase A(EC 3.4.2.1) synthetic substrates and solubilizes elastin. It had only one polypeptide chain with a molecular weight of about 28000 daltons, a high thermal stability in the presence of calcium ions, a pH optimum of about 6.8, and a maximal caseinolytic activity at about 50°C.
Characterization of hydrocarbon emulsification and solubilization occurring during the growth of Endomycopsis lipolytica on hydrocarbons
Authors: Roy P. K. , Singh H. D. , Bhagat S. D. , Baruah J. N. 
Published: December 2004

AbstractA comparative characterization of the phenomena of hydrocarbon emulsification and solubilization taking place during the growth of Endomycopsis lipolytica on n‐alkanes and alkenes was made. Evidence was obtained for the cellular production of different factors involved in emulsification and solubilization of hydrocarbons. It was shown that the production of these factors closely followed cell growth. The inducible nature of the alkane solubilizing factor was demonstrated using actidione as inhibitor. Whereas emulsifying factor was demonstrated using actidione as inhibitor. Whereas emulsifying factors showed a broad affinity to some particular hydrocarbons, solubilizing factor was found to be highly specific for the particular hydrocarbon on which the cells were grown. The emulsifying factor was heat stable whereas the solubilizing factor was highly unstable even at −4°C. Metal‐ion chelating agents strongly inhibited the activity of both of the factors. A crude isolate of the alkane emulsifying factor was obtained and its peptide characteristics were demonstrated. Using EDTA as an inhibitor for the emulsification–solubilization activity, evidence was obtained for the predominent role played by the emulsification–solubilization mechanism in the uptake of alkane by yeast cells.
Lipase synthesis in hydrocarbon fermentation
Authors: Kosaric N. , Zajic J. E. , Aboue G. , Jack T. , Gerson D. 
Published: December 2004

AbstractA Study was undertaken to establish conditions and relationships for the production of lipases during hydrocarbon fermentation. A culture of Candida lipolytica was isolated by a kerosene enrichment technique from oil‐soaked soil and this microbe was used to study the production of lipase on a kerosene–mineral salts medium. The optimum pH, medium, and temperature for lipase synthesis were established and the properties of the isolated enzyme in terms of its activity and lipid specificity were studied.
Production of Candida utilis protein from peat extracts
Authors: Quierzy P. , Therien N. , Leduy A. 
Published: December 2004

AbstractSphagnum peat extracts or hydrolysates have been obtained and used as a culture medium for the production of Candida utilis biomass as single cell proteins. Acid hydrolysis of ground peat (4–60 mesh) in an autoclave operated under a set of conditions for acid strength (0.3‐1.5 (v/v) H2SO4), holding time (1–4 hr), temperature (100–165°C), and weight ratio of dry peat to solution (3.3–16.7 g dry peat/100 g solution) yielded carbohydrate‐rich extracts of different concentrations (1–34g/liter). The best yield (mg total carbohydrate/g dry peat) was obtained for a holding time of I hr and a temperature of 152°C. Low peat concentratio (4.1 g dry peat/100 g solution)resulted in high yield(280mg total carbohydrate/gdry peat) with a corresponding low carbohydrate content in hydrolysate (13 g/liter), while a lower yield with a higher carbohydrate content (34 g/liter)in hydrolysate were found when increasing peat concentration (16.7 g dry peat/100 g solution). Shake‐fladk experiments using peat hydrolysates as the culture medium together with NH4OH (∼4.8 g/liter) and K2HPO4(5 g/liter) as nitrogen and phosphate supplement, respectively, gave a maximum biomass concentration of 7.5 g/liter after 60 hr at 30°C and 200rpm. Batch cultivation in a fermentor under controlled conditions for aeration (4.2 liter/min), agitation (500rpm), temperature (30°C), and pH (5.0) produced a maximum biomass of 10 g/liter after 20 hr with a specific growth rate of 0.13 hr−1. For the continuous cultivation, a maximal biomass productivity of 1.24 g/gliter‐he was obtained at a dilution rate of 0.125 hr −1. Monod's equation's equation has been used for the estimation of the coefficients μMax, Ks, and Y. It was found that the yield coefficient Y is not constant during the progress of batch cultivation.
Continuous‐flow monitoring of lactose concentration
Authors: Volesky B. , Emond C. 
Published: December 2004

AbstractA specific continuous‐flow analytical system for determination of lactose concentration in a liquid mixture of constituent sugars was developed and tested based on a series of enzymatic reactions. Lactose and glucose oxidase immobilized on a phenol–formaldehyde resin were employed. More detailed study was carried out based on a reaction by‐product quantitatively detected by an available iodide electrode. A multichannel proportioning pump fed two independently operated analytical streams eliminating thus the background glucose interference. With a goal of lactose concentration control in a fermentation process, the system response time delay was shortened to approximately 15 min. Apart from optimization of the analytical system operating parameters, the study indicates also the major application problem areas: lactase inhibition by galactose, galactose oxidation by glucose oxidase, and a partial loss of glucose oxidase activity in a prolonged continuous‐flow operation. A manual Colorimetric Procedure was employed to verify the results of the potentiometric method.
Use of continuous‐culture techniques for determining the growth kinetics of a celluloytic Thermoactinomyces sp.
Authors: Lee S. Edward , Humphrey Arthur E. 
Published: December 2004

AbstractIn order to better understand the kinetics of cellulose degradation by Thermoactinomyces sp., continuous‐culture experiments were performed utilizing the various intermediates of cellulose degradation as the feed substrates. Steady‐state data from the glucose runs suggest that this organism has a growth yield of 0.42 g cell/g glucose, and a specific maintenance of 0.24 g glucose/g cell/hr. The Monod equation did not seen to model the growth well, since a plot of 1/D vs. 1/S gave a maximum specific growth rate that was even lower than one of the steady‐state dilution rates. A dynamic washout experiment suggested a maximum specific specific growth rate of 0.36 hr−1 and indicated that glucose is only slightly growth inhibitory as the inhibition constant, Ki, is 19 g glucose/liter. An equation for substrate concentration for washout conditions was derived. This equation predicted the transient glucose concentration relatively well. A fill‐and‐draw technique was investigated for determination of the growth parameters. It was not successful because of difficulties in contamination and accurately monitoring the dissolved oxygen in the small highly agitated vessel. However, the technique could be useful in studying the growth characteristics of sludge in a waste treatment system where contamination is not a worry. One could cover the medium surface and use a nonsterilizable dissolved oxygen probe of high sensitivity membrane to overcome these difficulties.