ISSN:0006-3592    

DOI:10.1002/bit.260080202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractIn three series of experiments, 3‐l., 20‐l., and 150‐l. bacterial cultures were grown in stirred, deep culture vessels to average bacterial cell densities of 71 × 108, 63 × 108, and 43 × 108viable organisms per milliliter, respectively, and then infected with phage. The average yield of progeny phage in each case was ca. 3000 mpfu (minimum plaque‐forming units) per cell. Thus, the average mass of phage obtained in the 3‐l. experiments was not less than 124 mg./l., calculated from the plaque counts, assuming a particle size of 3.6 × 106Daltons for the μ2 phage. This is about twentyfold higher than is obtainable by conventional methods in aerated, shaken culture flasks. The actual phage yields are probably much higher than the minimum values calculated from plaque counts. For example, in the case of one of our culture lysates which was purified at King's College, the efficiency of plating was shown to be only 19%. The carbon dioxide evolution rate of cultures was measured and used as a guide to the time at which phage should be added. In this way, greater control of cultural conditions was obtained than is possible in shaken flasks. For the best yield of phage per milliliter of culture, the optimum time for phage infection was such that bacterial lysis just prevented the carbon dioxide evolution rate from reaching its potential maximum. The major factor influencing the phage yield per milliliter of culture was the aeration capacity of the culture vessel used. All had maximum aeration capacities much higher than those obtainable in shaken culture flasks. Cultures grown and infected in 3‐l. Vessel operated under conditions of low aeration gave poor yields of phage. The reason for th

ISSN:0006-3592    

DOI:10.1002/bit.260080203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractA brief review of the development of our knowledge about hydrogen bacteria is presented, with emphasis on the characteristics and physiological differences of variousHydrogenomonasspecies. One species,Hydrogenomonas eutropha, is discussed in greater detail. Nutritional requirements, physical factors affecting growth, and equipment used for culturing 100‐ml. shake cultures and 15‐1.mass cultures ofH. eutrophaare described. Cell‐free extracts ofH. eutrophacarry out the oxyhydrogen reaction as demonstrated by the alternate reduction and oxidation of endogenous flavins and cytochromes by molecular hydrogen and oxygen, respectively. Spectra of cell‐free extracts of this organism show the presence of cytochromes of thecandb1types. A cytochrome of theotype was also found, but none of theacytochromes were detected. The sum of a series of enzymatic reactions shown to be catalyzed by these extracts can account for the oxidation of hydrogen by

ISSN:0006-3592    

DOI:10.1002/bit.260080204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractExtremely halophilic bacteria, which are able to grow in, and require, saturated or near‐saturated salt solutions are both of historical interest and of practical importance as food spoilage organisms. In addition, because of the environment in which they live, their membranes, enzymes, and ribosomes have unusual or unique properties that make them especially worthy of physiological study. A simple method for growing large quantities of extreme halophiles is described, and various growth media, both complex and synthetic are discusse

ISSN:0006-3592    

DOI:10.1002/bit.260080205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractThe insect pathogenBacillus popilliaeDutky causes a fatal milky disease of Japanese beetle larvae. Spores of the bacterium offer a biological means of controlling this insect. While satisfactory sporulationin vitrohas not yet been accomplished, conditions have been developed for the proliferation of vegetative cells in shaken flasks and aerated fermentors. Vegetative cultures are maintained by frequent transfer or by lyophilization. Media based on yeast extract are used routinely, but corn steep liquor and casein hydrolyzates afford comparable yields of 5 × 108cells/ml. in 16–24 hr. Nutritional requirements have been established for growth in a synthetic medium. Oxygen availability affects the pathway of carbohydrate catabolism and is necessary for optimal growth. In rapidly growing cultures, a short period of maximum viability is characteristically followed by rapid death of the cells. When inoculum size and transfer time are suitably manipulated, viable cell yields reach 1–2 × 109/ml. Alternative methods of propagation, including the addition of particulate carbon, and procedures designed either to neutralize acids or to remove metabolic products by dialysis, do not markedly enhance the yield of cells per volume of medium, although viability may be prol

ISSN:0006-3592    

DOI:10.1002/bit.260080206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractA chemically defined medium forMicromonospora purpureahas been devised, consisting of glucose, a nitrogen source, calcium carbonate, magnesium sulfate, dibasic potassium phosphate, and the required trace quantities of iron, copper, zinc, and manganese. Using washed cell inocula, dry mycelial weights of more than 16 mg./ml. were obtained in 7‐day shaken‐flask fermentations. Nutrient requirements forM. purpureaare discussed and growth data presented. Sucrose, maltose, starches and dextrins could be substituted for glucose, and resulted in good growth of the organism. A number of amino acids and inorganic nitrogen‐containing compounds were capable of utilization as sole nitrogen sources. Weekly serial transfers of the culture in defined medium have shown no diminution in mycelial weights over a four‐month

ISSN:0006-3592    

DOI:10.1002/bit.260080207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractOur program on the mass cultivation of basidiomycetes was designed to determine whether these organisms, being more highly differentiated than bacteria, molds, and yeasts, would in turn carry out markedly different reactions on natural products. A discussion of our methods of isolating and characterizing a representative collection of basidiomycetes and of our difficulties in obtaining pure cultures which grew well is presented. Some information we obtained on the growth and types of products that these organisms produced in a synthetic medium is discussed. Our techniques for examining fermentation beers for transformation products from indole compounds and from progesterone are explained, and the types of products we obtained are described.

ISSN:0006-3592    

DOI:10.1002/bit.260080208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractGrowth of the ciliate,Colpoda steinii, was studied in shake flasks, 30‐l., stirred jars, and a conventional 50‐gal. stainless‐steel fermentor. This organism was growth with either washed or unwashedEscherichia colicells as the sole food source. Generation times of 3–4 hr. were obtained at 30°C. With average yields of 78% (0.78 g. of protozoa/g. of bacteria). In a 100‐l. fermentation, a dry weight concentration of 12.5 g./l. (1.04 × 107protozoa/ml.) was reached by means of periodic addition ofE. colipaste. The influence of bacterial concentration on the growth rate of the protozoa was also investigated. It was found that this relationship could be represented by a Michaelis‐Menten equation with a maximum specific growth rate of 0.23 hr.−1(3‐hr. generation time) and a bacterial concentration for half‐maximum growth rate of

ISSN:0006-3592    

DOI:10.1002/bit.260080209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractObservations on quantitative relationships between oxygen diffusion rate and product formation were made with penicillin, bacitracin, and gluconic acid. For penicillin and gluconic acid formation, no toxic oxygen concentration could be achieved in the broth, whereas concentration above approximately 7 mg. O2/l. suppressed the bacitracin yield to an ever increasing extent. The intensity of mixing was measured by means of distributing a dye. With penicillin formation as an example, it was shown that the antibiotic yield is not only dependent on maintenance of a certain oxygen diffusion rate, but also on ensuring a necessary minimal mixing.

ISSN:0006-3592    

DOI:10.1002/bit.260080210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260080211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY