Mechanical Agitation and Rheological Considerations of Ale Yeast Slurry

Stoupis, T; Stewart, Graham G.; Stafford, Robert A.

doi:10.1094/asbcj-60-0058

Cited by 7 publications

(9 citation statements)

References 3 publications

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“…Sebrané kvasnice byly vystaveny míchání s rotační rychlostí 550, 750 a 900 rpm. Se stoupající rotační rychlostí dochá-zelo ke snižování viability, vyššímu zákalu piva, snížení stability pivní pěny, zvýšení pH piva a mechanickému poškození buněk (Stoupis et al, 2002).…”

Section: Stirringunclassified

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Storage of Pitching Yeast in Brewery

Kopecká¹,

Kubizniaková²,

Fidrich³

et al. 2017

Kvasny Prum

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Section: Stirringunclassified

“…Harvested yeast was exposed to stirring with rotational speed 550, 750 and 900 rpm. Higher rotational speed results in a decrease of viability, higher beer haze, reduction of beer foam stability, increasing beer pH and mechanical damage of cells (Stoupis et al, 2002).…”

Section: Poděkovánímentioning

confidence: 99%

Storage of Pitching Yeast in Brewery

Kopecká¹,

Kubizniaková²,

Fidrich³

et al. 2017

Kvasny Prum

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“…It has been reported that beer haze can result from the yeast cell wall releasing mannan 2,8,35,36 as it is processed during centrifugation. Additionally, several reports have confirmed mannan, which is unfilterable from the medium, to be a constituent of haze material 19,35,38 . Haze was derived from pieces of material released from the yeast wall exterior as cells passed through the centrifuge.…”

Section: Beer Haze Mannan and Particle Size As A Function Of G-forcementioning

confidence: 99%

“…Previous reports have shown 2,8,9,17,18,38 that these stresses can cause a decrease in cell viability and flocculation, cell wall damage, increased extracellular proteinase A (PrA) levels, hazier beers and reduced beer foam stability. In this study, biological indicators of yeast physiology such as viable and damaged cells, intracellular pH, glycogen and trehalose levels as well as beer physical stability parameters including mannan residues, particle size, and beer haze have been employed to quantify the damage which occurs to yeast as a function of cycles through a centrifuge operating at high and low G-forces.…”

Section: Introductionmentioning

confidence: 99%

Disc Stack Centrifuge Operating Parameters and Their Impact on Yeast Physiology

Chlup

Bernard

Stewart

2008

Journal of the Institute of Brewing

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Hydrodynamic stresses imposed on brewing cells of Saccharomyces cerevisiae during beer processing can have a detrimental impact on beer quality. The use of centrifuges has become an efficient way to increase brewery throughput as they decrease clarification times and improve fermenter and tank conditioning efficiency. The effect of a disc stack centrifuge on yeast and beer physical stability has been investigated. In this study, a commercial ale yeast strain has been subjected to different operating conditions during centrifugation. Cell viability and intracellular pH decreased due to processing conditions encountered during yeast cropping with a centrifuge. A relationship has been established that yeast cell wall mannan, an unfilterable haze constituent, as a function of G-force and centrifugation cycles, is released from the cell wall while concurrently, particle sizes between 0.5-2.8 μm and beer haze increased. Furthermore, yeast intracellular glycogen and trehalose levels were depleted as a result of centrifugation.

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“…[6,8] In microchannels, the medium flows over the adhered or suspending cells while markedly influencing cell growth, cellular function, and viability regardless of the cell type. [20][21][22] This is because hydrodynamic forces acting on the cell surface induce cell deformation and decrease in cell-substrate interactions (for anchorage-dependent cells), thus affecting cellular viability, function, and gene expression. In addition to anchorage-dependent cells, the gene expression of the budding yeast, Saccharomyces cerevisiae, is affected by shear stress.…”

mentioning

confidence: 99%

Fabrication of Hollow Polymeric Microstructures for Shear‐Protecting Cell‐Containers

et al. 2008

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Microfluidic systems have played a major role in the development of high-throughput cell screening, biological analysis, cell-based biosensors, and tissue engineering because they offer miniaturized systems with reduced use of reagents, short reaction times, increased speed of analysis, potential for parallel operation, and precise control/monitoring of cellular behavior. [1][2][3][4][5] In cell-based microfluidic devices, it is important to capture living cells in predefined locations of the microfluidic channel.[6] In addition, continuous nutrition, oxygen supply, and waste removal through the culture medium must be ensured for long-term cell culture. [7,8] Previous studies have demonstrated immobilization of anchorage-dependent cells within particular regions of a microfluidic channel by utilizing laminar flow, [9,10] prepatterned ligands, [11] addressable microfluidic networks, [12] cell-encapsulating hydrogels, [13][14][15][16] or engraved microwells. [17][18][19] Despite the success of these approaches, there are still potential limitations that restrict the widespread use of these techniques. For example, the patterned regions are restricted to the flow of a laminar stream in laminar flow patterning, while the cell encapsulation inside hydrogels is usually irreversible and compromises cell viability owing to exposure to a toxic photoinitiator and radiation. Cell docking into microwells by exploiting stationary conditions (sedimentation) or a receding meniscus is also an attractive strategy for shear protection because of its simplicity and low-expertise requirements. However, the cells can be flooded in a subsequent analysis and damaged by a laminarly flowing stream, resulting in shear-induced alteration in cell behavior.A critical factor for proper functioning of cell-based microdevices is the minimization of shear stress from a medium flow. [6,8] In microchannels, the medium flows over the adhered or suspending cells while markedly influencing cell growth, cellular function, and viability regardless of the cell type. [20][21][22] This is because hydrodynamic forces acting on the cell surface induce cell deformation and decrease in cell-substrate interactions (for anchorage-dependent cells), thus affecting cellular viability, function, and gene expression. In addition to anchorage-dependent cells, the gene expression of the budding yeast, Saccharomyces cerevisiae, is affected by shear stress.[23]It is therefore desirable to take shear damage into account when designing and fabricating microchannel or bioreactor. [7] This Communication addresses a method of forming bottleshaped, hollow polymeric microstructures inside a microfluidic channel for potential shear-protecting cell reservoirs. In particular, the geometry of the cell container was tailored such that the width of the neck is narrower than that of the bottom, capable of offering diffusive mass transport and stable, noninvasive microenvironment against shear stress. Using these hollow structures as cell-docking containers, yeast cells were captured ...

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Mechanical Agitation and Rheological Considerations of Ale Yeast Slurry

Cited by 7 publications

References 3 publications

Storage of Pitching Yeast in Brewery

Storage of Pitching Yeast in Brewery

Disc Stack Centrifuge Operating Parameters and Their Impact on Yeast Physiology

Fabrication of Hollow Polymeric Microstructures for Shear‐Protecting Cell‐Containers

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