ISSN:0006-3592    

DOI:10.1002/bit.260231202

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe development and validation of short‐term tests for carcinogens and mutagens are urgently needed if estimates of 70–80% for environmentally induced cancer are valid. Several methods forin vitrotesting have been described in microbial and mammalian cells. It is anticipated that a battery of tests will soon be available with high degree of reproducibility and predictability for potentialin vivocarcinogenesis. This review discusses those assays currently being implemented in mammalian cells including a brief description of the methodology, advantages, and disadvantages, and the correlation with knownin vivoactiv

ISSN:0006-3592    

DOI:10.1002/bit.260231203

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

年代:1981

数据来源: WILEY

摘要:

AbstractThis report reviews recent progress in micro carrier technology at the Massachusetts Institute of Technology. This progress includes new understanding of the nutritional needs of high‐cell density micro carrier cultures, the demonstration of cell growth on microcarriers in a hormone‐supplemented, serum‐free medium, and the continuous cell propagation of epithelial cell types in microcarrier culture by medium modification that permits efficient bead‐to bead transfer. Also, a technique for obtaining large quantities of mitotic cells by selective detachment from microcarriers is reported. Finally, recent progress in interferon production from human foreskin fibroblasts grown on microcarriers is outlined: Our improvements in the interferon “super induction” process have increased the interferon yield per cell fivefold

ISSN:0006-3592    

DOI:10.1002/bit.260231204

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

年代:1981

数据来源: WILEY

摘要:

AbstractRegeneration of whole plants from isolated protoplasts (plant cells devoid of cell walls) provides a novel capability that is potentially useful for crop improvement efforts. Such a regeneration capacity has been developed for the commercial potato cultivar ‘russet Burbank,’ currently the most popular cultivar in production. Due to fertility problems of this cultivar, the improvement of ‘russet Burbank’ by classical breeding procedures has been limited. Examination of a large population of protoplast‐derived clones has revealed the variation for a number of traits can be observed. Variation observed under laboratory conditions and in field trials includes changes in plant morphology and tuber‐setting characteristics, as well as alterations in response to environmental and pathogen stress. A brief description of the cloning process and the potential for application of cloning technology in crop plant improvement will b

ISSN:0006-3592    

DOI:10.1002/bit.260231205

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

年代:1981

数据来源: WILEY

摘要:

AbstractIn vitrocell culture has proven to be a valuable procedure for the study of cellular function as well as the production of veterinary and human vaccines. In recent years, interest in cell culture technology has grown due to the need for production of interferon, monoclonal antibodies, various hormones, and other cell‐secreted products with potential medical uses. Many of these products have been successfully produced only be cells which require attachment to a surface in order to grow and function. This requirement places severe limitations on the economics and feasibility of large‐scale culture. In response, a number of new technologies have been proposed and developed in attempts to increase the surface area available within a given culture volume, to increase the cell density per surface area, to decrease medium and serum requirements per unit of product, to increase product production by control of the cellular environment, and to automate the production process. Some of the techniques and described along with their ability to control the environment of cells in cult

ISSN:0006-3592    

DOI:10.1002/bit.260231206

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe Cell Culture Center at the University of Alabama in Birmingham was set up to produce large quantities of cells and their products from suspension cultured cell lines. This system has now been in operation for over five years and has been effective in producing large quantities of mammalian cells of murine and human origin. This article describes the system and some growth parameters which have been of importance for large‐scale mammalian cell growt

ISSN:0006-3592    

DOI:10.1002/bit.260231207

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe effect of mild NaOH treatments on sugarcane cellulosic wastes (bagasse, pith, and straw) to increase their biological degradability has been studied. At a level of 8% NaOH (on a dry matter basic) 60% digestibility measured by thein vitrotechnique was achieved for all materials tested. Indirect methods to predict the digestibility of treated materials such as the bacterial degradability, enzymatic degradability, hot‐water solubility, and chemical oxygen demand were tried as alternative methods to the rumen fluid technique. High correlation coefficients for all materials were obtained with all alternative techniques. The minimal r value was 0.96 while the highest was 0.99. An important reduction of time and reagents is achieved by the utilization of the solubility and chemical oxygen demand test

ISSN:0006-3592    

DOI:10.1002/bit.260231208

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

年代:1981

数据来源: WILEY

摘要:

AbstractA mild new method for the immobilization whole microbial cells has been developed. Cells were suspended in a solution of preformed, linear, water‐soluble Polyacrylamide chains, partially substituted with acylhydrazide groups. The Prepolymerized backbone polymer was crosslinked, in the presence of viable cells, by stoichiometric amounts of dialdehydes such as glyoxal, glutardialdehyde, and period ate‐oxidized polyvinyl alcohol. The crosslinking reaction, carried out in cold, neutral physiological conditions resulted in cells entrapped in gels with physical properties similar to those of the common Polyacrylamide gels. However, cell damage generally caused by the acrylamide monomer was avoided. RestingStreptomyces clavuligeruscells, possessing a high capacity for antibiotic production, were entrapped according to this procedure. These immobilized cells produced cephalosporins continuously for 96 h with yields similar to those of free resting cells. The same cells, when immobilized by direct polymerization acrylamide monomers, yielded significantly lower amount of antibiot

ISSN:0006-3592    

DOI:10.1002/bit.260231209

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

年代:1981

数据来源: WILEY

摘要:

AbstractParticulate materials (flowers of sulfur, fluorapatite, glass beads, and pyrite) inhibited the growth ofThiobacillus ferrooxidanson ferrous iron at pH 1.5. The degree of inhabitation varied with the type of the particulate and culture conditions. The inhibition caused by pyrite involved a soluble toxic component. The inhibition caused by sulfur particles and glass beads was alleviated by incubation under static culture conditions (i.e., no shaking) but oxidation rates declined because of lack of aeration an increase in the pH above 2 also relieved the inhibition. The nature of inhibition. The nature of inhibition by different particles varied from declined iron oxidation rates to prolonged lag periods depending on the concentration of the test material. Thus, the results indicate that the bacterial activity at the liquid‐solid interface is different from that in the bulk liquid phase and is influenced by the proton concentration and by the physiochemical properties of the solid

ISSN:0006-3592    

DOI:10.1002/bit.260231210

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe optimal substrate profile is calculated by Pontryagin's maximum principle for a simplified mathematical model of microbial growth and product formation. This model is fitted to experimental data of turimycin fermentation. Sub optimal control is studied for comparison.

ISSN:0006-3592    

DOI:10.1002/bit.260231211

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

年代:1981

数据来源: WILEY