Cheese yeasts

Abstract

Numerous traditionally aged cheeses are surface ripened and develop a biofilm, known as the cheese rind, on their surfaces. The rind of such cheeses comprises a complex community of bacterial and fungal species that are jointly responsible for the typical characteristics of the various cheese varieties. Surface ripening starts directly after brining with the rapid colonization of the cheese surface by yeasts. The initially dominant yeasts are acid and salt‐tolerant and are capable of metabolizing the lactate produced by the starter lactic acid bacteria and of producing NH3 from amino acids. Both processes cause the pH of the cheese surface to rise dramatically. This so‐called deacidification process enables the establishment of a salt‐tolerant, Gram‐positive bacterial community that is less acid‐tolerant. Over the past decade, knowledge of yeast diversity in cheeses has increased considerably. The yeast species with the highest prevalence on surface‐ripened cheeses are Debaryomyces hansenii and Geotrichum candidum, but up to 30 species can be found. In the cheese core, only lactose‐fermenting yeasts, such as Kluyveromyces marxianus, are expected to grow. Yeasts are recognized as having an indispensable impact on the development of cheese flavour and texture because of their deacidifying, proteolytic, and/or lipolytic activity. Yeasts are used not only in the production of surface‐ripened cheeses but also as adjunct cultures in the vat milk in order to modify ripening behaviour and flavour of the cheese. However, yeasts may also be responsible for spoilage of cheese, causing early blowing, off‐flavour, brown discolouration, and other visible alterations of cheese.

Saprochaete clavata Outbreak Infecting Cancer Center through Dishwasher

“…could actually have been contaminated by S. clavata. However, to our knowledge, no report has associated S. clavata with cheese production (20).…”

Occurrence of Yeasts in White-Brined Cheeses: Methodologies for Identification, Spoilage Potential and Good Manufacturing Practices

“…Inhibitory properties of LAB against potential spoilage yeasts have been examined for several fermented milk products, mainly yogurts, sour cream, and surface-ripened cheese ( Corsetti et al, 2001 ; Crowley et al, 2013 ; Delavenne et al, 2013 ; Laèanin et al, 2017 ; Fröhlich-Wyder et al, 2019 ; Garnier et al, 2019 ). The studies commonly pointed out that the antifungal activity of LAB was strain-specific and depended on the target yeast species and/or strains.…”

“…Studies on interactions within yeast consortium have been preferably focused on surface-ripened cheeses and fermented milk products, however, similar interaction mechanisms are foreseen in white-brined cheeses ( Fröhlich-Wyder et al, 2019 ). Interactions within the yeast communities are facilitated by several communication mechanisms referred as quorum sensing (QS), which regulate such fungal behaviors as growth, sporulation, biofilm production, secretion of virulence factors, etc.…”

Evaluation of Technological and Probiotic Abilities of Local Lactic Acid Bacteria

“…The review differentiates commensalism where one of the partners is stimulated by the production of an essential substance or by the destruction of an inhibitory factor, and mutualism where, in this case, the interaction is beneficial to both partners [72,73].…”