Yeast Quality and Fluorophore Technologies

Zandycke, Sylvie M. Van; Simal, O.; Gualdoni, S.; Smart, Katherine A.

doi:10.1002/9780470696040.ch14

Cited by 3 publications

(2 citation statements)

References 24 publications

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“…A methylene blue staining was performed with some modifications [ 93 , 94 ]. Briefly, C. albicans cells (1 × 10 6 cells/mL) were exposed to different TG concentrations (2–64 µM) in PBS.…”

Section: Methodsmentioning

confidence: 99%

Antifungal Activity of the Frog Skin Peptide Temporin G and Its Effect on Candida albicans Virulence Factors

D’Auria

Casciaro

Angelis

et al. 2022

IJMS

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The increasing resistance to conventional antifungal drugs is a widespread concern, and a search for new compounds, active against different species of fungi, is demanded. Antimicrobial peptides (AMPs) hold promises in this context. Here we investigated the activity of the frog skin AMP Temporin G (TG) against a panel of fungal strains, by following the Clinical and Laboratory Standards Institute protocols. TG resulted to be active against (i) Candida species and Cryptococcus neoformans, with MIC50 between 4 µM and 64 µM after 24 h of incubation; (ii) dermatophytes with MIC80 ranging from 4 to 32 µM, and (iii) Aspergillus strains with MIC80 of 128 µM. In addition, our tests revealed that TG reduced the metabolic activity of Candida albicans cells, with moderate membrane perturbation, as proven by XTT and Sytox Green assays, respectively. Furthermore, TG was found to be effective against some C. albicans virulence factors; indeed, at 64 µM it was able to inhibit ~90% of yeast–mycelial switching, strongly prevented biofilm formation, and led to a 50% reduction of metabolic activity in mature biofilm cells, and ~30–35% eradication of mature biofilm biomass. Even though further studies are needed to deepen our knowledge of the mechanisms of TG antifungal activity, our results suggest this AMP as an attractive lead compound for treatment of fungal diseases.

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Section: Methodsmentioning

confidence: 99%

Antifungal Activity of the Frog Skin Peptide Temporin G and Its Effect on Candida albicans Virulence Factors

D’Auria

Casciaro

Angelis

et al. 2022

IJMS

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“…It is true that viability tests allow discrimination between cells but only at a very general level since the criteria used to define viability differ between individual procedures. In particular, those viability tests that rely on differential staining may probe disparate properties such as dye exclusion/membrane competence, staining of intracellular components by dyes taken up through to modification of stains via the activities of endogenous enzymes ( 90 ) .…”

Section: All For One or One For All?mentioning

confidence: 99%

Provocation: all yeast cells are born equal, but some grow to be more equal than others

Boulton¹

2021

J. Inst. Brew.

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Yeast is central to the brewing process and as such deserves great care and attention to ensure it is fit‐for‐purpose. It is widely accepted that assessment based on simple viability testing is useful but far too blunt an instrument to give much useful information regarding the physiological state of the live yeast cells within the population. The need to address this issue has spawned a plethora of procedures collectively termed ‘vitality tests’. The concept of yeast vitality is nebulous, and this goes some way to explain why no single test has been universally adopted. There is, however, another major flaw in the underlying assumptions of the majority of vitality tests. This is, most are based on bulk samples which ignore heterogeneities within the population of cells being examined. The asymmetric mode of proliferation of Saccharomyces yeasts means that mother and daughter cells are always unequal. Individual cells have finite lifespans, old cells die and must be replaced with new fitter progeny. We are fortunate in that budding yeasts are widely used as a model cell for studies into ageing in higher eukaryotes and as a result there is a huge and ever‐expanding body of literature devoted to this subject. This has shown that yeast populations comprise several distinct sub‐populations which respond differently to external messengers. These messengers may be generated by one sub‐set of the population and received and acted upon by another indicating a degree of cooperation designed to ensure survival of the whole. Death of individuals within populations can be as a result of the application of lethal external stresses but more usually is a programmed process in which targeted cells commit suicide in an expression of altruism for the greater good of the whole. On reflection, perhaps this is unexpected but perfectly logical behaviour for single celled organisms to adopt. Most yeast population studies have been performed using haploid laboratory strains cultivated under relatively defined conditions. The industrial scale model is, of course, far removed from this. Brewing yeast strains are very different, and the complexities of serial fermentations and associated yeast handling processes introduce added layers of complexity. Nevertheless, there is every reason to believe that similar population heterogeneities and cooperative behaviour exist within the context of brewing. The thrust of the arguments presented in this article is that we should embrace this and consider individual cells within yeast populations within a fermenter, for example, as being individual free‐living components of a multicellular organism. Further, intercellular cooperation is managed by a network of messenger molecules many of which are likely to trigger the global shifts associated in metabolic activities which accompany the reversible passage from growth to quiescence and which coincidentally are likely to be of importance in beer flavour. The purpose of this article is to argue that the majority of current yeast vitality tests are not fit...

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