bluuebunny/crossref_metadata_2025_split huggingface dataset:
A ventilated germ‐free cabinet for the microbiological laboratory
Authors: Harris‐Smith R. , Pirt S. J. , Firman J. E. 
Published: May 2005

AbstractThe design of a cabinet for the aseptic manipulation of material is described. The interior surfaces of the cabinet are sterilized by swabbing with a germicide. Germ‐free conditions are maintained during operation by means of a positive pressure of sterile air. A fan and filter unit attached to the cabinet is used to blow sterile air into the cabinet in sufficient quantity so as to flow out of the hand ports at a velocity of 50 ft./min. In the design, careful consideration was given to the ease of manipulations in the cabinet.
Biosynthesis of 7‐chloro‐6‐demethyltetracycline in the presence of certain homocysteine derivatives and methoxinine
Authors: Neidleman S. L. , Albu Evelyn , Bienstock Evelyn 
Published: May 2005

AbstractAddition of the S‐2‐hydroxyethyl‐, S‐2‐chloroethyl‐, S‐n‐propyl‐, and S‐iso‐propyl‐derivatives of homocysteine, and methoxinine to S. aureofaciens (ATCC 13900) fermentations resulted in production of 7‐chloro‐6‐demethyltetracycline in addition to the normally synthesized 7‐chlortetracycline.
Beta‐carotene production in 20‐liter fermentors
Authors: Ciegler Alex , Lagoda Adolph A. , Sohns Virgil E. , Hall Harlow H. , Jackson Richard W. 
Published: May 2005

AbstractMicrobiological production of beta‐carotene previously investigated in shakenflask culture has been scaled‐up to 20‐liter fermentors containing an operating volume of 10‐liters. Yields obtained in shaken flasks, approximately 100 mg./100 ml. have been reproduced with a fermentation time of 72 hr. Factors affecting the fermentation: inoculum, mash ingredients, and environmental conditions, were investigated. Typical data are presented. A preliminary cost analysis indicates a “cost to make” of $31.35/kg. of carotene contained in the dried fermentation solids.
Plate assay methods for amino acids. 2. Factors affecting the cup plate assay for lysine with Streptococcus faecalis ATCC 6057
Authors: Bolinder Arne E. , Lie Sturla , Ericson L.‐E. 
Published: May 2005

AbstractA number of factors was found to affect the cup plate assay for lysine with Streptococcus faecalis ATCC 6057. Hydroxylysine, aspartic acid, and Tween 80 were found to be among the essential components of the assay medium. Removal of any of these three components produced diffuse growth zones or otherwise unsatisfactory plates. The inclusion of asparagine and additional dipotassium phosphate to the medium was found to be advantageous but not an absolute requirement. It was important not to autoclave the hydroxylysine and the additional dipotassium phosphate together with the rest of the assay medium, but to add these components to the sterilized medium immediately before pouring the plates. With certain concentrations of hydroxylysine in the medium, the addition of L‐glutamine was found to potentiate the effect of hydroxylysine and thereby improve the lysine plates. The effect of graded amounts of the above mentioned medium components and of the pH of the assay medium was also studied. Increasing the sterilization time of the medium from 5 to 10 min. at 120°C. improved the readability of the lysine plates and led to more easily reproducible results. Factors influencing the preparation of the inoculum for the lysine plates were also studied: the age of the stab culture, the amount of inoculum used per plate, and the influence of the nature of the suspension medium used for washing the inoculum.
Effect of pressure waves on bacteria suspended in water
Authors: Lundbeck H. , Sköldberg O. 
Published: May 2005

AbstractShock pressure waves with a frequency of 50/sec. and a maximal pressure of 60–70 kg./cm.2 greatly reduced the viability of E. coli. A similar effect was obtained also on staphylococci, enterococci, Salmonella Zanzibar, and coliphages T2. On the contrary no effect on spores of B. subtilis was found. The effect was practically independent of the maximal pressure within the range from 30–80 kg./cm.2, the highest pressure tested. The effect decreased with increasing cell density of the bacterial suspension. Bacteria surviving shock treatment died considerably more rapidly when stored at 4°C. than bacteria treated in the same way except for exposure to pressure waves. Morphological examinations with the aid of ordinary light microscopy as well as electron microscopy suggest that the effect was due to mechanical action on the bacterial cell walls.
Criteria for biodegradable syndets
Authors: Barnhart Edwin L. , Eckenfelder W. Wesley 
Published: May 2005

AbstractWith the emphasis being given to the development of biologically soft detergents, it is necessary to establish eriteria defining biodegradability of these materials. It is the authors' opinion that a biologically soft detergent should have the following characteristics: (1) Under normal operations the material should be 85% removable by activated sludge. (2) Normally high discharges of the detergent should not influence biological activity. (3) The detergent should ultimately degrade to carbon dioxide and water.
Reproduction of distillers' yeasts
Authors: de Becze George I. 
Published: May 2005

AbstractDistillers' yeasts, strains of Saccharomyces cerevisiae, although capable of sexual reproduction, in distillery practice reproduce asexually, by budding. A cell may bring forth another one in 50 min. With every ounce of whiskey produced, 30 billion new cells come to existence. Within a few days, in 4–8 propagation stages, a test tube full of culture will populate 100,000 gallons beer with 150 million cells per ml. Rate of reproduction, the number of new cells per each original cell varies from 5 to 50 in the various propagation stages. The number of new cells produced in a given nutrient is independent from the number of initial cells; and the utilization of the nutrient increases with the dilution of the substrate. Although distillers' yeasts may reproduce at such extremes as 1–46°C, 2½–10½ pH, presence of 0–15% alcohol by volume, and 0.1–25% sugar content, in distillery practice the factors are so selected to maintain conditions close to the optimum. When placed in the nutrient the initial cells will measure the chemical and physical characteristics of the new living space and the cell population, and will prepare a design of reproduction best suited to the conditions. The design includes a symmetry in the grouping of the cells and a rhythmic timing in starting new buds. Each healthy cells is biologically equal to the others and is capable of performing all functions characteristic of the strain. In spite of the sensitive coordination system between the individual cells that regulates their activity, marked differences exist among the cells to the degree of cell individuality. Distillers yeasts are superbly equipped to live and reproduce.
Aeration‐agitation studies on the rifamycin fermentation
Authors: Virgilio A. , Marcelli E. , Agrimino A. 
Published: May 2005

AbstractAeration and agitation conditions in 250 l. baffled fermenters with different impeller diameters, speeds, and air flows were studied during fermentations for the production of rifamycin, a new antibiotic produced by Streptomyces mediterranei. Dissolved oxygen concentration was continuously measured and the courses of power input, oxygen diffusion rate QO2, dry weight, viscosity, pH, sugar utilization, and antibiotic titer determined. Higher antibiotic yields occurred when the oxygen demand of the culture was satisfied and an excess of dissolved oxygen was still present during a critical period of the fermentation between the 50th and the 80th hr. To meet this requirement a power input of about 3.0 w./l. and an air flow ranging from 0.8 to 1.5 l./l./min. were found to be necessary.
Bacterial sulfide production from sulfate‐enriched spent distillery liquor. III.
Authors: Ghose T. K. , Mukherjee S. K. , Basu S. K. 
Published: May 2005

AbstractSemicontinuous sulfide fermentation has been conducted with distillery spent liquor as the source of carbon employing a strain similar to Desulphovibrio rubentschikii. Mineral barites and gypsum have been used as the hydrogen acceptors during the studies. Results reveal that mineral barites can also react very favorably as hydrogen acceptors. Sulfates have been used both in powdered (200 mesh) and lumpy (1/4‐1/2 in. size) forms. When applied in lumpy form in a packed tower, both the mineral sulfates produced higher yields of sulfide compared to their corresponding finely pulverized states. Thus, under similar conditions, fermentation conducted with pulverized gypsum showed a yield of 450–550 p.p.m. hydrogen sulfide, whereas the yield was as high as 750–1025 p.p.m. when gypsum lumps were used as a packing. Corresponding figures with barites are 300 and 540 p.p.m., respectively. Continuous sulfide fermentation has also been conducted in a packed tower containing lumpy gypsum as the packing under total recirculation. Daily buildup of sulfide was observed to be as high as 180 mg./l. of fermenting medium. Appreciable reduction in COD of the effluent was observed during the above studies. Thus, with barites, per cent COD reduction values were 30–35, 45–50, 60–65, and 75–80 with retention periods of 10, 15, 25, and 35 days, respectively. With gypsum, per cent COD reduction was 50–70 with 10 days's residence time. The effects of the retention period on sulfide yield and volatile acid content were also studied. The longer the retention period, the higher is the sulfide yield and the lower the volatile acid content of the discharge becomes. Studies were also conducted to find the correct composition of volatile acids in the discharge, as well as the levels of their concentration during continuous feeding and discharge over a number of days. It has been observed that during 18 hr. of fermentation in a batch, volatile acid concentration increased from 6.76 m. to 15.01 mmoles per liter of medium of which 10 mmoles are acetic, 0.833 mmoles butyric, and 4.16 mmoles propionic acid. Studies on soluble and insoluble sulfate balance have also been made in a synthetic medium containing calcium acetate as the substrate. Unaccounted for sulfates were negligible and a deviation between the actual and calculated sulfide yield did not exceed 2%. It is also observed that, when fermentations are conducted in sulfate packed columns, the color of the effluent becomes paleyellow containing very little suspended and volatile matter compared to the deep‐black color of the emuent emerging from a ferrnenter fed with pulverized sulfates. This liquor contains 0.5271% soluble ash (computed as potash) and might be a good source of potash.
Growth of a yeast of normal alkanes
Authors: Miller Thomas L. , Lie Sturla , Johnson Marvin J. 
Published: May 2005

AbstractA soil isolate, HD‐5, identified as closely resembling Candida intermedia, was grown on normal alkanes ranging from dodecane (C12) to octadecane (C18). The growth rate of the organism increased with increasing length of the alkane chain. The shortest generation time was 4.5 hr. with octadecane as the carbon source. Cell yields of 82% were common with even numbered alkanes from C14 through C18. The cell yields appeared to decrease with shorter chain (C12 or below) and odd‐numbered chain alkanes. The cellular nitrogen ranged from 6.9 to 7.5% and the highest lipid content found was 10.3% (with C17).
Studies on the purification of vaccinia virus
Authors: Orlando M. D. , Riley J. M. , Patrick W. C. 
Published: May 2005

AbstractVarious methods for the removal of extraneous matter from vaccinia virus suspensions are described and compared. Of ten procedures tested, differential centrifugation and Freon extraction were the most successful. Both the partially purified suspensions and the dried products prepared from them had high virus titers in embryonated eggs and high infectivity for mice. Although both processes resulted in products with the same titers, the differentially centrifuged product was approximately tenfold more purified as shown by the percentage solids of the suspensions before freeze drying.
Oxygen transfer mechanisms in the gluconic acid fermentation by Pseudomonas ovalis
Authors: Bennett Gary F. , Kempe Lloyd L. 
Published: May 2005

AbstractThe oxygen uptake rate to suspended cells of Pseudomonas ovalis was measured in two ways using the same cell suspension. Initially the rate was found by measuring the rate of production of gluconic acid by cells suspended in a nitrogenfree, aerated medium. Then, an oxygen electrode was used to measure the rate of transfer of dissolved oxygen to cells suspended in a liquid that was being agitated but not sparged. These rates were markedly different. It was found that agitation affected the oxygen transfer rates in aerated solutions at dissolved oxygen concentrations well above the critical level, but had no affect on the oxygen uptake rates by cells suspended in an unsparged but agitated medium. The data suggested that an additional path existed for oxygen transfer. This alternate route, parallel to the conventional pathway of oxygen transfer, becomes operative when the liquid films surrounding the cells and bubbles merge. The resulting shorter path presents a mechanism for direct transfer of oxygen which increases in importance as the gas−liquid interfacial area increases.
Flexibility in cultivation equipment. I. A small‐scale continuous culture apparatus for the study of complex processes
Authors: Holmström Björn , Hedén C.‐G. 
Published: May 2005

AbstractA cultivation apparatus made up from six small (80−800 ml.) glass units with independent pH‐, aeration‐, and foam control is described. Exchangeable attachments made it possible to run the unit both batchwise and continuous and to connect up the units in various fashions.
Die kontinuierliche Züchtung von Mikroorganismen als apparatives problem
Authors: Fiechter A. 
Published: May 2005

AbstractBei der kontinuierlichen Züchtung von Mikroorganismen ist die zuverlässige Aufrechterhaltung des stationären Zustandes die Grundbedingung für die erfolgreiche Untersuchung der biologischen Probleme. Auftretende Instabilitäten können apparativen oder biologischen Ursprunges sein; eine einwanddfrei funktionierende Ausrüstung ist daher bei der Einführung der Kontinuität primäres Erfordernis. Es wird auf die wichtigsten Ursachen, welche zu Instabilitäten führen können, eingegangen und eine Laborapparatur beschrieben, welche eine Basisausrüstung umfasst, die speziell für hohe Betriebssicherheit und Einfachheit der Bedienung ausgelegt wurde. Besondere Aufmerksamkeit wurde der Konstanz des Zuflusses f des Mediums, und des arbeitenden Volumens v, sowie der sicheren Ausschaltung von Infektionen durch Verwendung sterilisierbarer pH‐Elektroden und eines Membranverschlusses geschenkt.
Sterilization of microbiological media with β‐propiolactone
Authors: Holme Tord 
Published: May 2005

AbstractA procedure for sterilization of microbiological media with β‐propiolactone has been developed. Special attention was paid to the maintenance of mild conditions to enable the treatment of media sensitive to high temperature or low pH. The maximum temperature allowed was 40°C. and automatic neutralization of acid produced during hydrolysis was effected by the use of titration unit. The apparatus could be used for several successive sterilization cycles without disconnection.
Production of industrial‐grade polysaccharide B‐1459
Authors: Rogovin P. , Albrecht W. , Sohns V. 
Published: May 2005

AbstractA method to make purified polysaccharide synthesized exocellularly from cereal carbohydrates by the bacterium Xanthomonas campestris NRRL B‐1459 and a characterization of its properties have been reported previously by this Laboratory. Because of increasing commercial interest in a less purified polymer, we have extended our work to include production of a lower cost industrial‐grade product. Fermentation of media containing 2.25% corn sugar, seeded with 5% inoculum of X. campestris NRRL B‐1459 and cultured aerobically at 82°F., is complete in 96 hr. The viscous fermented broth contains about 1.5% polymer. A tan product containing approximately 60% polymer and having good viscosity characteristics is obtained by drum drying the fermented broth at steam pressures below 40 p.s.i.g, 287°F. Drying at higher temperatures adversely affects viscosity. A good product is also obtained by spray drying. Cost estimates indicate that 5 million lb./yr. of dried crude solids could be produced for 37 cents/lb. by drum drying or for 41 cents a pound by spray drying.
Changes in acid soluble nucleotide components of candida utilis during the cell cycle
Authors: Hampton A. N. , Dawson P. S. S. 
Published: May 2005

AbstractAcid soluble extracts obtained at 30 min intervals from cells of C. utilis growing in synchrony in a phased culture (cycle time 51/2 hr) were fractionated on a Dowex‐1‐formate column. The series of fractionation profiles showed changes in number and amounts of components over the cell cycle. Transient accumulations of numerous components over the complex pool were observed. The significance of the changes are discussed in relation to practical applications and cell metabolism.
Adriamycin, 14‐hydroxydaimomycin, a new antitumor antibiotic from S. Peucetius var. caesius
Authors: Arcamone F. , Cassinelli G. , Fantini G. , Grein A. , Orezzi P. , Pol C. , Spalla C. 
Published: May 2005

AbstractStreptomyces peucetius var. caesius, obtained from S. peucetius, the daunomycin producing microorganism, by mutagenic treatment, differs from the parent culture by the color of the vegetative and aerial mycelia and by its antibiotic, producing ability. S. peucetius var. caesius accumulates adriamycin in submerged and aerated culture on a medium containing glucose, brewer's yeast, and inorganic, salts both in shake flasks and in stirred fementers. Isolation of the product is performed by solvent extraction, chromatography on buffered cellulose columns, and crystallization as the hydrochloride. The new antitumor agent, adriamycin, is the 14‐hydroxv derivative of daunomyein.
Biosynthesis of chloramphenicol
Authors: Westlake D. W. S. , Vining L. C. 
Published: May 2005

AbstractThe current knowledge concerning the biosynthesis of chloramphenicol is discussed. Cultures of Streptomyces sp. 3022a fed 14C‐shikimie acid incorporated the label to the same extent into phenylalanine, tyrosine, and chloramphenicol. Of possible precursors of the phenylpropanoid nucleus of this antibiotic only p‐aminophenylalanine and DL‐threo‐p‐amino phenylserine specifically labeled chloramphenicol. On the basis of these results a pathway for the biosynthesis of chloramphenicol is presented. The lack of specific incorporation of 15N‐nitrogen from a competitive feeding experiment in which both l5N‐nitrate and 14N‐DL‐serine were fed to growing cultures suggests that both the amido‐ and the nitro‐nitrogen atom present in this antibiotic are derived from a common pool. Studies on the enzyme, DAHP synthetase, show that in streptomyces sp. 3022a it is not subject to feed back inhibition by either phenylalanine, tyrosine, or chloramphenicol.
Activation of the biosynthesis of carotenoids by Blakeslea trispora
Authors: Ninet L. , Renaut J. , Tissier R. 
Published: May 2005

AbstractThe research carried out by several scientists has made possible the industrial preparation of β‐carotene by fermentation. A fungus, Blakeslea trispora, abundantly synthesizes carotenoids when its two opposite forms are cultivated together in a special fatty medium. When ionones or other natural substances are introduced into the culture, a very obvious increase in the biosynthesis of carotenoids, more specifically of β‐carotene, is obtained.Our own work has shown that; (1) several synthetic products chemically related to β‐ionone, such as 2,6,6‐trimethyl‐l‐acetyleyelohexene, can advantageously replace either partially or totally the ionones as inductors of the biosysnthesis of β‐carotene; (2) various nitrogen‐containing substances when added to the culture medium can considerably enhance the biosysnthesis of carotenoids while sometimes very specically orienting it. Their action comes on top of that of the ionones or their substitutes; actually this action is unexplained.Thus certain amides, imides, lactams, hydrazides, or substituted pyradines, and in particular succinimide and isonicotinoylhydrazine, have produced a two or threefold increase in the quantity of β‐carotene present in the culture media of Blackeslea trispora.Conversely some heterocyclic substances such as pyridine itself or imidazole totally inhibit the biosysnthesis of β‐carotene but induce the production of very important quantities of lycopene.
Transformation of steroids by mixed cultures
Authors: Ryu D. Y. , Lee B. K. , Thoma R. W. , Brown W. E. 
Published: May 2005

AbstractSome results of our studios on transformation of steroids by mixed culture fermentation are presented in this paper. Arthrobacter simplex was paired in turn with each of the following: Streptomyces roseochromogenes, Curvularia lunata, Absidia coerulea, and Aspergillus ochraceus. The steroid substrates examined for multiple transformation were 16α‐hydroxy‐cortexolone, 16α‐hydroxy‐cortexolone 16,17‐acetonide, 9α‐fluorohydrocortisone, 9α‐fluorohydrocortisone 21‐acetate, and 9α‐fluorohydrocortisone 21‐hemisuccinate. The effects of media, steroid substrate, and microbial interaction in a mixed culture on the induction and repression of steroid transforming enzymes were unique to each case studied. The reaction mechanism of the multiple steroid transformation was also found to vary from one mixed culture system to another. Two different reaction mechanisms were observed, namely, consecutive and parallel. In the former, one of the two enzymatic reactions always preceded the other, while in the latter, two different enzyme reactions occurred simultaneously, thereby giving rise to two different intermediates. Multiple transformation of steroids by a single step mixed culture fermentation has potential economic advantages.
Oxygen absorption in microbiological systems of zero order reaction rate
Authors: Tsao George T. 
Published: May 2005

AbstractA model of oxygen absorption in microbiological systems of zero order reaction rate is proposed. The partial differential equation was solved to predict the profile of the oxygen concentration boundary layer next to a gas‐liquid interface. Generally speaking, the presence of microbial cells always helps to increase the oxygen absorption rate over that of physical absorption. Only when the microbiological reaction is slow as judged by the fact that the reaction time, tr, is much larger than the diffusion time, tD, can one rightfully approximate the oxygen absorption in microbiological suspensions by physical absorption.
Continuous fermentation to produce xanthan biopolymer: Laboratory investigation
Authors: Silman R. W. , Rogovin P. 
Published: May 2005

AbstractXanthan biopolymer has been produced by single‐stage continuous fermentation with Xanthomonas campestris NRRL B‐1459 in a medium of glucose, minerals, distillers' solubles, and urea for as long as 20 days. At the highest dilution rate studied (D = 0.0285 hr−1), the steady state rate of xanthan production was 0.36 g/kg/hr and the steady state yield, basis glucose consumed, was 68%. Observations indicate that xanthan production rate is a function of pH and D.
A wet spinning apparatus and auxiliary equipment suitable for preparing samples of oriented DNA
Authors: Rupprecht A. 
Published: May 2005

AbstractSamples of oriented DNA prepared by wet spinning have been found to be very useful for physicochemical and biochemical studies with various techniques. The results obtained yield information on such fundamental properties of DNA as its hydration, electrical conductivity, and its interaction with irradiation and mutagenic and carcinogenic substances. Against this background a detailed description is given of the wet, spinning apparatus and of the techniques developed to produce bigger samples from spun films of oriented DNA. Photographic illustrations are used to give a clear picture of the various details. Extensions of the wet spinning method are discussed.