Bioprocess

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

In situ magnetic separation for extracellular protein production

Abstract: A new approach for in situ product removal from bioreactors is presented in which high-gradient magnetic separation is used. This separation process was used for the adsorptive removal of proteases secreted by Bacillus licheniformis. Small, non-porous bacitracin linked magnetic adsorbents were employed directly in the broth during the fermentation, followed by in situ magnetic separation. Proof of the concept was first demonstrated in shake flask culture, then scaled up and applied during a fed batch cultivation in a 3.7 L bioreactor. It could be demonstrated that growth of B. licheniformis was not influenced by the in situ product removal step. Protease production also remained the same after the separation step. Furthermore, degradation of the protease, which followed first order kinetics, was reduced by using the method. Using a theoretical modeling approach, we could show that protease yield in total was enhanced by using in situ magnetic separation. The process described here is a promising technique to improve overall yield in bio production processes which are often limited due to weak downstream operations. Potential limitations encountered during a bioprocess can be overcome such as product inhibition or degradation. We also discuss the key points where research is needed to implement in situ magnetic separation in industrial production. Biotechnol. Bioeng. 2009;102: 535–545. © 2008 Wiley Periodicals, Inc.

One-pot multi-enzymatic production of purine derivatives with application in pharmaceutical and food industry

Abstract: Biocatalysis reproduce nature’s synthetic strategies in order to synthesize different organic compounds. Natural metabolic pathways usually involve complex networks to support cellular growth and survival. In this regard, multi-enzymatic systems are valuable tools for the production of a wide variety of organic compounds. Methods: The production of different purine nucleosides and nucleoside-5′-monophosphates has been performed for first time, catalyzed by the sequential action of 2′-deoxyribosyltransferase from Lactobacillus delbrueckii (LdNDT) and hypoxanthine-guanine-xanthine phosphoribosyltransferase from Thermus themophilus HB8 (TtHGXPRT). Results: The biochemical characterization of LdNDT reveals that the enzyme is active and stable in a broad range of pH, temperature, and ionic strength. Substrate specificity studies showed a high promiscuity in the recognition of purine analogues. Finally, the enzymatic production of different purine derivatives was performed to evaluate the efficiency of multi-enzymatic system LdNDT/TtHGXPRT. Conclusions: The production of different therapeutic purine nucleosides was efficiently catalyzed by LdNDT/TtHGXPRT. In addition, the resulting by-products were converted to IMP and GMP. Taking all of these features, this bioprocess entails an efficient, sustainable, and economical alternative to chemical synthetic methods.

Monitoring bioreactors using principal component analysis: production of penicillin G acylase as a case study

Abstract: The complexity of biological processes often makes impractical the development of detailed, structured phenomenological models of the cultivation of microorganisms in bioreactors. In this context, data pre-treatment techniques are useful for bioprocess control and fault detection. Among them, principal component analysis (PCA) plays an important role. This work presents a case study of the application of this technique during real experiments, where the enzyme penicillin G acylase (PGA) was produced by Bacillus megaterium ATCC 14945. PGA hydrolyzes penicillin G to yield 6-aminopenicilanic acid (6-APA) and phenyl acetic acid. 6-APA is used to produce semi-synthetic β-lactam antibiotics. A static PCA algorithm was implemented for on-line detection of deviations from the desired process behavior. The experiments were carried out in a 2-L bioreactor. Hotteling’s T2 was the discrimination criterion employed in this multivariable problem and the method showed a high sensibility for fault detection in all real cases that were studied.

Identifying Analytics for High Throughput Bioprocess Development Studies

Abstract: In recent years, high throughput screening (HTS) studies have been increasingly employed as an integral element of bioprocess development activities. These studies are often limited by an analytical bottleneck; they generate multiple samples for analysis and the available analytical methods cannot always cope with the added analytical burden. A potential solution to this challenge is offered by the deployment of appropriate analytics. This article outlines features of analytical methods that affect their fit to high throughput (HT) applications. These are discussed for a range of analytics frequently used in bioprocess development studies of monoclonal antibodies. It then outlines how these features need to be considered in order to classify analytical methods in terms of their particular application in high throughput scenarios.