Showing papers in "Journal of Biotechnology in 1992"

TL;DR: In this paper, a collaborative investigation of assays for endo-1,4-β-xylanase activity based on production of reducing sugars from polymeric 4-O-methyl glucuronoxylan was conducted.

TL;DR: In this article, the authors showed that LDH release could be a good indicator of cellular damage of many cell lines, especially during shear stress or sonication, and found a significant correlation between the number of dead cells, determined by Trypan Blue staining, and LDH activity measurements in the supernatant of hybridoma strains, whatever the culture conditions.

TL;DR: This chapter discusses two distinct groups of yeasts—namely, glucose insensitive and glucose-sensitive yeasts, and indicates that there are possibly differences in internal metabolite concentrations, which may be expressed in the different regulatory responses.

TL;DR: The Biomass Monitor proved suitable for precise on-line monitoring of both homogeneous (uni-cellular) and heterogeneous (mycelial) cultures in bioreactors.

TL;DR: The characteristics and the time course of the yeast cell cycle were found to be strongly dependent on the physiological environment and the dynamic growth characterization.

TL;DR: The X-ray studies of pure lipases will enable the establishment of the structure-function relationships and contribute for a better understanding of the kinetic mechanisms of lipase action on hydrolysis, synthesis and group exchange of esters.

TL;DR: There is still no general approach that guarantees a long-term, high producing approach to the production of secondary metabolites, but some techniques have proven to work in a number of cases.

TL;DR: TB/C3 mouse hybridoma cells have been grown at 2 controlled dO2 conditions by headspace and sparged oxygenation by identifying bubble-cell interactions at the air-medium interface where bubbles bursting in clusters and of a size less than 5 mm appear to be the most lethal.

TL;DR: The filamentous fungus, Trichoderma reesei produces all of the enzymatic activities required for efficient hydrolysis of highly ordered crystalline cellulose, and the availability of high-resolution three dimensional structures of the two domains allows genetic engineering to be used for detailed structure-function studies of these important enzymes.

TL;DR: This paper discusses the concept of generic model-based software sensors with particular reference to bioprocess application and presents two different procedures--an adaptive linear model based method, and a method based upon artificial neural networks.

TL;DR: Substrate shifts during synchronous growth caused by changing substrate uptake properties are proposed to be responsible for the cyclic initiation of proliferation activity.

TL;DR: Analysis of RNA recovered from the filtrate supports the notion that a functionally active protein-synthesizing machinery is superorganized in a dynamic complex.

TL;DR: Some of the most important measurement techniques are reviewed in order to provide an evaluation of their current state and emphasis is given to the underlying principles and on-line capability which allow to judge their importance and potential for exploitation resulting in well (maybe entirely) controlled bioprocesses in the future.

TL;DR: A theoretical model based on the surface active properties of Pluronic F-68 was proposed to account for its protective effect on cell growth and monoclonal antibody production in stirred and sparged bioreactors for both serum-supplemented and serum-free media.

TL;DR: A fuzzy inference (approximate reasoning) is used for decision making in analogy to human thinking, facilitating a more sophisticated control of reactor control by traditional control technology.

TL;DR: The decision as to which cell culture system should be chosen, whether batch or continuous processes should be applied essentially is based on the capital investment, the amount of material to be produced, genetic stability of the production cell line, reliability of sterile technology and the flexibility required in the production plant.

TL;DR: A model scheme for the development of a commercially available drug, produced by bioconversion, and perspectives are discussed, including the performance of bioconversions by freely suspended and immobilized plant cells or enzyme preparations.

TL;DR: Batch culture is the traditional and, for most purposes, the preferred production technology for animal cells and when scale-up was needed, particularly from multiple roller bottles, the simplest way forward was to adopt the bacterial-type stirred tank reactor.

TL;DR: Recent progress that has been made in the elucidation of the secretion pathway in Gram-positive bacteria is outlined and potential applications in strain improvement for the industrial production of extracellular proteins are discussed.

TL;DR: For on-line monitoring of bioprocesses present applications are mainly restricted to gas analysis, but several techniques have been improved recently: membrane probes, the application of MS/MS techniques, methods of correlating available on- line data like gas reaction rates with biopROcess characteristics using stoichiometric models and other empirical correlations.

TL;DR: It was concluded that the reduced production of bacterial beta-galactosidase was due to reduced polyhedrin promoter-driven synthesis.

TL;DR: These responses indicate that during slow growth, the addition of L-glutamine increases the availability of cellular ATP generated by mitochondrial respiration which stimulates some posttranscriptional step in the pathway of mAb secretion such as the rate of H or L chain translation, chain assembly, interorganelle transport or vesicular transport from the Golgi to the cell membrane.

TL;DR: The application of biotechnology to the synthesis of antiviral agents including those which are not nucleoside analogues will be discussed.

TL;DR: Based on a discussion of technical, process related, and economic/market bottlenecks it is concluded that the often mentioned productivity argument in favor of continuous processing is much too simple.

TL;DR: The current and potential biotechnological applications of image analysis and image processing systems are reviewed and it is expected that image analysis systems will allow more rapid and accurate quantification of numerous biotehnological analyses.

TL;DR: (R)-2-Hydroxy-4-phenylbutyric acid, an intermediate in the manufacture of inhibitors of angiotensin converting enzyme, can be produced continuously in an enzyme membrane reactor by enzymatic reduction of its corresponding alpha-keto acid by D-LDH.

TL;DR: The relative enzyme activities and the amount of ammonia produced during growth indicated that glutamine is oxidized preferentially via the transamination pathway and suggests that transport may regulate glutamine metabolism.

TL;DR: Two different pathways for morphogenesis in vitro have been recognised, direct and indirect where plants can be obtained from the explant indirectly or directly via organogenesis or embryogenesis, considered as one of the most widely used commercial method of regeneration.

TL;DR: A single-stage fed-batch bioprocess for the production of a recombinant protein beta-galactosidase, by E. coli has been developed and inhibition of growth and protein expression caused by excessive concentrations of glucose and acetate was investigated and subsequently minimized with an incremental nutrient feeding schedule.