ISSN:0006-3592    

DOI:10.1002/bit.260060202

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

年代:1964

数据来源: WILEY

摘要:

AbstractSugar molasses of high specific activity is prepared by photosynthesizing C14O2into sugar in a leaf of the Canna plant and then extracting the sugar. WhenT. utilisis grown in such a medium about 45% of the radioactivity is incorporated into the yeast cell; the remaining radioactivity is carbon dioxide and volatile organic compounds. The cells are now randomly labeled in all carbon compounds. Distribution of C14in the major cell components, such as protein, polysaccharide, and nucleic acids is shown.Nucleic acid is extracted from the cells and subject to chemical and enzyme action, for the preparation of randomly labeled ribonucleotides. Proteins are isolated and hydrolyzed to yield high specific activity amino acids, up to 150 mc. per millimole. Similarly polysaccharides are also isolated and from them high specific activity glucose and mannose are obtained by acid hydrolysis.By growingT. utilisin a medium containing C14‐8‐adenine and C14‐2‐uracil, these bases are about 90% incorporated into the nucleic acids of the cell. Using the same methods described for the uniformly labeled nucleic acid only base labeled nucleosides and nucleotides are prepared.Preparative procedures for the isolation of some of these compounds are discussed. The latest biochemical techniques for their purification are described. Methods for assaying for radiochemical purity and problems concerining stability of high specific activity compounds are di

ISSN:0006-3592    

DOI:10.1002/bit.260060203

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

年代:1964

数据来源: WILEY

摘要:

AbstractThe equipment and operational techniques are described which were found suitable to control pH in the range 6.8–7.8 pH, within ±0.03 pH units of the desired value, at cell concentrations up to a maximum of 2.5 × 106/ml. The results of batch growth of a suspension strain of the BHK cell (clone 13) under conditions of controlled pH are given and the significance of these results is discus

ISSN:0006-3592    

DOI:10.1002/bit.260060204

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

年代:1964

数据来源: WILEY

摘要:

AbstractA method has been devised for the estimation in fermentation media, of 1‐dehydro‐17‐α‐methyltestosterone in the presence of 17‐α‐methyltestosterone. This method involves the extraction of the steroids with chloroform, and spectrophotometric measurement of the chromogen formed by a specific color reaction with sulfuric acid and 1‐dehydro‐17‐α‐methyltestosterone. The fermentation liquor and 17‐α‐methyltestosterone do not interfere. With this rapid (30 min.) method, quantitative tests on the progress of the steroid transformation can be made at frequent intervals during one fermentation run, these tests yielding the necessary information for an adequate control of the optim

ISSN:0006-3592    

DOI:10.1002/bit.260060205

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

年代:1964

数据来源: WILEY

摘要:

AbstractSolubilization of proteins from cereals, legumes, and oil seed cakes by alkali peptization and isoelectric precipitation is adversely affected if the source material is pretreated by ethanol or cooked under pressure. The degree of hydrolysis by trypsin of protein isolates obtained from unautoclaved materials is, however, considerably raised by heat treatment prior to enzymatic digestion.

ISSN:0006-3592    

DOI:10.1002/bit.260060206

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

年代:1964

数据来源: WILEY

摘要:

AbstractA 2000 l. 1 m. deep mass culture of algae was operated with continuous stirring, as an open system. The system behaved as an ecological unit selecting the most favored species. The ecological conditions could be modified by stirring speed and pattern in the tank. Methods for improving yields and utilization of CO2are described. Assessment of algal species for suitability in mass cultures is discussed. Yields obtained were 13 g. dry matter/sq. m. illuminated area/day.

ISSN:0006-3592    

DOI:10.1002/bit.260060207

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

年代:1964

数据来源: WILEY

摘要:

AbstractDistillers' yeasts, strains ofSaccharomyces 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 a

ISSN:0006-3592    

DOI:10.1002/bit.260060208

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

年代:1964

数据来源: WILEY

摘要:

AbstractA method of performing electrophoretic separations in a thin horizontal layer of continuously flowing buffer has been developed. The theoretical considerations that make possible the use of a thin layer for stabilization against convection effects, without the assistance of a packing material, are discussed. The apparatus is described together with an example of its performance, and a comparison with that of other workers.

ISSN:0006-3592    

DOI:10.1002/bit.260060209

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

年代:1964

数据来源: WILEY

摘要:

AbstractThe operation and construction of a liquid–liquid chromatography apparatus containing differentially permeable partions is described. The method is of value for the separation of heat sensitive and nonvolatile solute

ISSN:0006-3592    

DOI:10.1002/bit.260060210

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

年代:1964

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260060211

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

年代:1964

数据来源: WILEY