Maximizing the stability of metabolic engineering‐derived whole‐cell biocatalysts

Abstract

A systematic and powerful knowledge-based framework exists for improving the activity and stability of chemical catalysts and for empowering the commercialization of respective processes. In contrast, corresponding biotechnological processes are still scarce and characterized by case-by-case development strategies. A systematic understanding of parameters affecting biocatalyst efficiency, that is, biocatalyst activity and stability, is essential for a rational generation of improved biocatalysts. Today, systematic approaches only exist for increasing the activity of whole-cell biocatalysts. They are still largely missing for whole-cell biocatalyst stability. In this review, we structure factors affecting biocatalyst stability and summarize existing, yet not completely exploited strategies to overcome respective limitations. The factors and mechanisms related to biocatalyst destabilization are discussed and demonstrated inter alia based on two case studies. The factors are similar for processes with different objectives regarding target molecule or metabolic pathway complexity and process scale, but are in turn highly interdependent. This review provides a systematic for the stabilization of whole-cell biocatalysts. In combination with our knowledge on strategies to improve biocatalyst activity, this paves the way for the rational design of superior recombinant whole-cell biocatalysts, which can then be employed in economically and ecologically competitive and sustainable bioprocesses.

Polyelectrolyte Complex Beads by Novel Two-Step Process for Improved Performance of Viable Whole-Cell Baeyer-Villiger Monoxygenase by Immobilization

“…Stabilisation of the high enzyme activity of cells to achieve the maximum substrate conversion in repeated biotransformation cycles is one of the most important parameters in respect of the profitability of immobilized whole-cell biocatalysts [1]. At the same time, when using live cells, the need to maintain the highest degree of cell viability is also important.…”

“…High-viscosity, high-mannuronic acid sodium alginate from ISP Alginate (Girvan, UK) with the following chemical composition (determined by 1 It is also important to note that the PEC complex found throughout the volume of PEC beads provides additional mechanical resistance to the cells compared with the previously reported PEC capsule which contains the PEC membrane and the liquid core [25]. This can be seen in the course of the compression force where, after the disruption of a PEC bead at the point indicated by the arrow, a small decrease in the force occurred, followed by an increase in the bead resistance.…”

“…The immobilization of viable whole-cell biocatalysts has long been considered an important method for ensuring their recyclability and stabilisation for the development of the industrial production of chemical specialities and chiral drug precursors [1]. In particular, the combination of viable recombinant cells with overproduced enzymes and their immobilization facilitates recyclability and renders possible a continuous bioreactor arrangement with high application potential [2].…”

AFOB Special Issue on Industrial Biotechnology

“…Industrial biotechnology can also be described as the manipulation of enzymes and microorganisms to produce energy, industrial chemicals, and consumer goods through renewable resources of plant-derived carbohydrates and other compounds. [1] It can reduce the reliance on fossil fuels and yield cost effective and sustainable industrial processes.We have witnessed an enormous development of this field, due to promising approaches to address the most challenging issues in our society, including climate change, resource conservation, cost reduction, and sustainability. [2] Advancement in the fields of industrial biotechnology will influence the world more than we can anticipate now.…”

“…Industrial biotechnology can also be described as the manipulation of enzymes and microorganisms to produce energy, industrial chemicals, and consumer goods through renewable resources of plant-derived carbohydrates and other compounds. [1] It can reduce the reliance on fossil fuels and yield cost effective and sustainable industrial processes.…”