Showing papers on "Bioprocess published in 2001"

Sponge-microbe associations and their importance for sponge bioprocess engineering

Abstract: In recent years, a large diversity of sponge-microbe associations has been described: sponges can harbour archaea, eubacteria (including cyanobacteria), microalgae, fungi and probably also protozoa. The current paper gives a brief overview of the different types of associations and describes the potential influence of symbiotic micro-organisms on bioprocess design for the biotechnological production of sponge-associated natural compounds. It is concluded that the presence of microsymbionts may further complicate the already tedious development of sponge culturing techniques.

Assessment of near‐infrared spectral information for rapid monitoring of bioprocess quality

Abstract: Access to real-time process information is desirable for consistent and efficient operation of bioprocesses. Near-infrared spectroscopy (NIRS) is known to have potential for providing real-time information on the quantitative levels of important bioprocess variables. However, given the fact that a typical NIR spectrum encompasses information regarding almost all the constituents of the sample matrix, there are few case studies that have investigated the spectral details for applications in bioprocess quality assessment or qualitative bioprocess monitoring. Such information would be invaluable in providing operator-level assistance on the progress of a bioprocess in industrial-scale productions. We investigated this aspect and report the results of our investigation. Near-infrared spectral information derived from scanning unprocessed culture fluid (broth) samples from a complex antibiotic production process was assessed for a data set that incorporated bioprocess variations. Principal component analysis was applied to the spectral data and the loadings and scores of the principal components studied. Changes in the spectral information that corresponded to variations in the bioprocess could be deciphered. Despite the complexity of the matrix, near-infrared spectra of the culture broth are shown to have valuable information that can be deconvoluted with the help of factor analysis techniques such as principal component analysis (PCA). Although complex to interpret, the loadings and score plots are shown to offer potential in process diagnosis that could be of value in the rapid assessment of process quality, and in data assessment prior to quantitative model development.

Bioprocess development for serine alkaline protease production: a review

Abstract: This work is the result of the convergence of the research in biochemical reaction engineering and metabolic flux analysis for serine alkaline protease (SAP) production. The genus Bacillus includes a variety of industrially important species that are known to secrete a large number of extracellular proteases and are used among many species as producer of SAP enzyme. Therefore, in the first part of the present article an overview to serine alkaline protease and regulation of its synthesis and secretion in Bacillus is presented. In the second part, a detailed review of the published information on the bioprocess medium design and bioreactor operation parameters are discussed in relation to the concentrations of the byproducts, i.e. neutral protease, amylase, amino acids, organic acids and alcohols. In the third part, papers on metabolic flux analysis for SAP are reviewed with the emphasis on SAP overproduction potential of the Bacillus licheniformis, the effect of oxygen transfer on the bioreaction-network fluxes and the need for oxygen transfer strategies. The metabolic bottlenecks and strategies for increasing the yield and selectivity of SAP fermentation process are discussed. * To whom all correspondence should be addressed: Dr. Pinar Calik, Associate Professor, Department of Chemical Engineering, Middle East Technical University, 06531 Ankara, Turkey e-mail: pcalik@metu.edu.tr: Tel #: 00.90.312.210 43 85; Fax #: 00.90.312.210 12 64

Integrated Bioprocessing for Plant Cell Cultures

Abstract: Plant cell suspension culture has become the focus of much attention as a tool for the production of secondary metabolites including paclitaxel, a well-known anticancer agent. Recently, it has also been regarded as one of the host systems for the production of recombinant proteins. In order to produce phytochemicals using plant cell cultures, efficient processes must be developed with adequate bioreactor design. Most of the plant secondary metabolites are toxic to cells at the high concentrations required during culture. Therefore, if the product could be removed in situ during culture, productivity might be enhanced due to the alleviation of this toxicity. In situ removal or extractive bioconversion of such products can be performed by in situ extraction with various kinds of organic solvents. In situ adsorption using polymeric resins is another possibility. Using the fact that secondary metabolites are generally hydrophobic, various integrated bioprocessing techniques can be designed not only to lower toxicity, but also to enhance productivity. In this article, in situ extraction, in situ adsorption, utilization of cyclodextrins, and the application of aqueous two-phase systems in plant cell cultures are reviewed.

Method and apparatus for producing a biomaterial product

Abstract: A development tool (2) includes a plurality of measuring tools (71 to 76) and an industrial process simulation device (60). The simulation device (60) simulates a whole industrial scale bioprocess in order to obtain acceptable operating parameters for the industrial scale bioprocess. The measuring tools (71 to 76) enable various significant properties of the biomaterial to be measured and evaluated using only a small test quantity of the biomaterial.

Temporally segmented modelling: a route to improved bioprocess monitoring using near infrared spectroscopy?

Abstract: Near infrared spectroscopy (NIRS) was used to monitor an industrial bioprocess for the production of the antibiotic, tylosin, using a segmented modelling approach. Models were built over the entire time course of the fermentation from 0 to 150 h, and also in two distinct phases or segments of the bioprocess from 50 to 100 h (synthetic phase) and from 100 to 150 h (stationary phase). All models were validated externally and the performance of the full range and segmented models compared. The standard error of prediction (SEP) of the segmented models was less in both 50–100 h and 100–150 h and the correlation highest in the 50–100 h range. This would suggest that data segmentation is potentially a useful method of accommodating the impact of the pronounced matrix changes which occur in some bioprocesses in NIRS models for key analytes. While there are many reports on bioprocess monitoring using NIRS, there have been no previous studies on the use of segmented NIR models within a bioprocess as a means of accommodating matrix change.

Chemical, physical, and biochemical concepts in isolation and purification of proteins*

Abstract: * Reprinted from Separation Processes in Biotechnology; Asenjo, J.A., Ed.; Bioprocess Technology, Vol. 9; Marcel Dekker, Inc.; New York, 1990; 17–64.

An artificial intelligence tool for bioprocess monitoring: application to continuous production of gluconic acid by immobilized Aspergillus niger

Abstract: Experimental data on continuous fermentation of sucrose and glucose solution at low pH to gluconic acid by Asprgillus niger immobilized on cellulose fabric show complex dynamic behaviour including a decline in yield. The data have been analyzed using an artificial intelligence based symbolic regression technique to provide a mathematical model for predicting values of conversion 5, 10 and 15 h ahead values of conversion. These predictions can be used during continuous operations to monitor the bioprocess and adjust the residence time of fermentation to get complete and more efficient conversion of sucrose or glucose to gluconic acid.

Application of fluorescence spectroscopy for on-line bioprocess monitoring and control

Abstract: 12 Modern bioprocess control requires fast data acquisition and in-time evaluation of bioprocess variables. On-line fluorescence spectroscopy for data acquisition and the use of chemometric methods accomplish these requirements. The presented investigations were performed with fluorescence spectrometers with wide ranges of excitation and emission wavelength. By detection of several biogenic fluorophors (amino acids, coenzymes and vitamins) a large amount of information about the state of the bioprocess are obtained. For the evaluation of the process variables partial least squares regression is used. This technique was applied to several bioprocesses: the production of ergotamine by Claviceps purpurea, the production of t-PA (tissue plasminogen activator) by animal cells and brewing processes. The main point of monitoring the brewing processes was to determine the process variables cell count and extract concentration.

An integrated approach to bioprocess recipe design

Abstract: Biotechnical and food process industries have a need for tools that support the implementation of modern manufacturing practice. Flexible production strategies and total quality management require efficient design of the process recipes. This paper presents the approach used in Sophist, an adaptive recipe planning system. The system integrates case-based reasoning and a semi-qualitative process model for the design and optimisation of bioprocess recipes. In particular, we introduce a novel revision selection algorithm that improve the system's adaptivity. The behavior of the planner is exemplified by a batch fermentation planning experiment.

Electrically driven separation processes: analytical and preparative methods*

Abstract: Reprinted from Separation Processes in Biotechnology; Asenjo, J.A., Ed.; Bioprocess Technology, Vol. 9; Marcel Dekker, Inc.; New York, 1990; 517–568.

Optimal De-Batch Bioprocess Control Via Intelligent System Based on Hybrid Techniques

Abstract: This paper deals with the design of intelligent control for a bioprocess of Hansenula polymorpha yeast cultivation. The objective of the process control is to produce biomass in a desired physiological state. The work demonstrates that the designed Hybrid Control Techniques (HCT) are able to recognize some bioprocess pattern evolution using especially trained neural network, to estimate the modeling parameters and to globally control the bioprocesses with hierarchically put into operation: an expert system and a fuzzy controller. The design of the control algorithm is presented as well as its tuning through realistic simulations. Taking in consideration the synergism of different paradigms like fuzzy logic, neural network, and symbolic AI, in this paper we present a real and fulfilled intelligent control architecture with application in bioprocess control.

Method and composition for cell technology and metabolism technology

Abstract: PROBLEM TO BE SOLVED: To provide a method for evolving a new metabolic pathway and increasing a bioprocess. SOLUTION: This method is method for evloving the new metabolic pathway comprising the process generally called circulative sequence recombination in this disclosure and increasing the bioprocess. The circulative sequence recombination necessitates to carry out the repetitive cycle of recombination and screening or selection to evolve individual gene, whole plasmid or virus, multigene cluster or even whole genome. The technics like this necessitates no wide range of analysis and calculation needed in the conventional method on the metabolism technology.

Data mining based hybrid modelling and experimental design for bioprocess optimisation.

Abstract: The dynamics of growth and hyaluronidase production of Streptococcus agalactiae were formulated by a hybrid model. The fuzzy rules implemented in the model describing the inhibition of growth by lactate were generated from fermentation process data. The model was used for experimental design to minimize the model parameter estimation error as well to maximize the productivity.

A bioprocess for the generation of pluripotent cell derived cells and tissues

Abstract: The present inventors identified aggregation of embryoid bodies (EBs) as the cause of the difficulty in generating large numbers of the embryonic stem cells (ES) cell-derived tissues. To counter this, the invention provides a novel bioprocess where aggregation of EBs is physically prevented, such as by an encapsulating matrix, Liquid Suspension Culture- encapsulated (LSCe). As a result, EBs can be cultured in high cell density, well-mixed systems. Well-mixed conditions facilitate measurement and control of the bulk media conditions and allow for the use of scalable bioreactor systems for clinical production of tissue. Therefore, LSCe enables generation of ES cell-derived tissue on a clinical scale. The invention is also applicable to other types of pluripotent cells

Physiology of Insect Cells Cultured in a New Serum-Free Medium

Abstract: The use of insect cells for the production of recombinant proteins by the baculovirus expression system is a well-established technology. The scale-up of this system necessitates large media quantities and serum substitution. We report here the design of a new serum-free medium and the physiological behaviour of insect cells in this medium under relevant bioprocess conditions.