Bioprocess

About: Bioprocess is a research topic. Over the lifetime, 2219 publications have been published within this topic receiving 50972 citations.

Monitoring the physiological status in bioprocesses on the cellular level.

Abstract: The trend in bioprocess monitoring and control is towards strategies which are based on the physiological status of the organism in the bioprocess. This requires that the measured process variables should be biologically meaningful in order to apply them in physiologically based control strategies. The on-line monitoring equipment available today mostly derives information on the physiological status indirectly, from external variables outside the cells. The complementary approach reviewed here is to analyse the microbial cells directly, in order to obtain information on the internal variables inside the cells. This overview covers methods for analysis of whole cells (as a population or as a single cell), for groups of cellular components, and for specific compounds which serve as markers for a certain physiological status. Physico-chemical separation methods (chromatography, electrophoresis) and reactive analysis can be used to analyse elemental and macromolecular composition of cells. Spectroscopic methods (mass, dielectric, nuclear magnetic, infrared, and Raman) have only recently been applied to such complex multicomponent mixtures such as microbial cells. Spectroscopy and chemical separation methods produce large amounts of data, which can often be used in the best way by applying chemometrics. Some of the methods can yield information not just on the average of the microbial cell population, but also on the distribution of sub-populations. The suitability of the methods for on-line coupling to the bioprocess is discussed. Others not suitable for on-line coupling can be established in routine off-line analysis procedures. The information gained by the methods discussed can mainly be used to establish better knowledge of the basis for monitoring and control strategies. Some are also applicable in real-time monitoring and control.

Food enzymes immobilization: novel carriers, techniques and applications

Abstract: Food enzyme immobilization is a technology to mitigate various limitations of free enzymes in food processing. Versatile carriers such as agro-waste based materials, nano materials, and metal organic frameworks are developed to immobilize enzymes with improved enzymological characteristics to enable catalytic reactions to be carried out under sophisticated and extreme processing conditions. New fabrication technologies of immobilized food enzymes, for example, 3D printing and coaxial electrospraying also enhance enzyme functionality. Recent research on food enzyme immobilization is aimed at sustainability, cost-effectiveness, automation, high-throughput, multifunction, and safety. These developments enable new applications in food bioprocessing, food analyses, food control and food packaging, and so on.

Scaling up xylitol bioproduction: Challenges to achieve a profitable bioprocess

Abstract: Xylitol is a GRAS (Generally Recognized as Safe) polyol commonly used in the food industry and able to promote several benefits to the health. In addition, it can also be used as a building block molecule for the manufacture of different high-value chemicals. Currently, the commercial production of xylitol occurs by chemical route through the catalytic hydrogenation of xylose from lignocellulosic biomass. Since this is an expensive process due to the severe reactional conditions employed, the biotechnological route for xylitol production, which comprises the biological conversion of xylose into xylitol, emerges as a potential lower-cost alternative to obtain this polyol due to the milder process conditions required. However, the biotechnological route still presents important bottlenecks and challenges that impairs the process scaling up. Modern strategies and technologies that can potentially improve xylitol bioproduction include adaptive evolution of microbial strains to enhance their tolerance to inhibitors and the xylose uptake rate during the fermentation step; development of engineered microorganisms to result in higher xylose-to-xylitol bioconversion yields; as well as xylitol purification techniques to improve the recovery yields. Moreover, techno-economic analysis of the overall production chain is essential to identify the process viability for large-scale implementation as well as the steps requiring improvements. These are some key factors discussed in this review, which aims to provide insights for the development of a more economically competitive, less energy demanding and scalable new technology for xylitol production.

Single cell analysis applied to antibody fragment production with Bacillus megaterium: development of advanced physiology and bioprocess state estimation tools.

Abstract: Single cell analysis for bioprocess monitoring is an important tool to gain deeper insights into particular cell behavior and population dynamics of production processes and can be very useful for discrimination of the real bottleneck between product biosynthesis and secretion, respectively. Here different dyes for viability estimation considering membrane potential (DiOC2(3), DiBAC4(3), DiOC6(3)) and cell integrity (DiBAC4(3)/PI, Syto9/PI) were successfully evaluated for Bacillus megaterium cell characterization. It was possible to establish an appropriate assay to measure the production intensities of single cells revealing certain product secretion dynamics. Methods were tested regarding their sensitivity by evaluating fluorescence surface density and fluorescent specific concentration in relation to the electronic cell volume. The assays established were applied at different stages of a bioprocess where the antibody fragment D1.3 scFv production and secretion by B. megaterium was studied. It was possible to distinguish between live, metabolic active, depolarized, dormant, and dead cells and to discriminate between high and low productive cells. The methods were shown to be suitable tools for process monitoring at single cell level allowing a better process understanding, increasing robustness and forming a firm basis for physiology-based analysis and optimization with the general application for bioprocess development.