A Wake-Up Call for the Efficient Use of the Bacterial Resting Cell Process, with Focus on Low Solubility Products

Moens, Esther; Bolca, Selin; Possemiers, Sam; Verstraete, Willy

doi:10.1007/s00284-020-01959-8

Cited by 2 publications

(1 citation statement)

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“…It is generally recognized that freeze-thaw cycles make cells leaky and can improve wholecell catalysis [58] and that cell membrane damage is dependent not only on the rates of freezing and thawing but also on the nature of the solutes in the suspending medium [59][60][61]. Washing cells in buffer also increases permeability and enhances catalysis with resting cells [53,62], but to our knowledge, whether this applies to glucose permeability has not been systematically studied. A systematic investigation of all factors that may contribute to membrane permeability was beyond the scope of the present study.…”

Section: Preliminary Studiesmentioning

confidence: 99%

Repurposing Inflatable Packaging Pillows as Bioreactors: a Convenient Synthesis of Glucosone by Whole-Cell Catalysis Under Oxygen

Mozuch

Hirth

Schwartz

et al. 2020

Appl Biochem Biotechnol

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Biocatalysis using molecular oxygen as the electron acceptor has significant potential for selective oxidations at low cost. However, oxygen is poorly soluble in water, and its slow rate of mass transfer in the aqueous phase is a major obstacle, even for laboratory-scale syntheses. Oxygen transfer can be accelerated by vigorous mechanical methods, but these are often incompatible with biological catalysts. Gentler conditions can be achieved with shallow, high surface area bag reactors that are designed for single use and generally for specialized cell culture applications. As a less-expensive alternative to these high-end bioreactors, we describe repurposing inflatable shipping pillows with resealable valves to provide high surface area mixing under oxygen for preparative synthesis of glucosone (D-arabino-hexos-2-ulose) from D-glucose using non-growing Escherichia coli whole cells containing recombinant pyranose 2-oxidase (POX) as catalyst. Parallel reactions permitted systematic study of the effects of headspace composition (i.e., air vs 100% oxygen), cell density, exogenous catalase, and reaction volume in the oxidation of 10% glucose. Importantly, only a single charge of 100% oxygen is required for stoichiometric conversion on a multi-gram scale in 18 h with resting cells, and the conversion was successfully repeated with recycled cells.

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