Biofilm formation by the yeastRhodotorula mucilaginosa: process, repeatability and cell attachment in a continuous biofilm reactor

Abstract

Yeast biofilms contribute to quality impairment of industrial processes and also play an important role in clinical infections. Little is known about biofilm formation and their treatment. The aim of this study was to establish a multi-layer yeast biofilm model using a modified 3.7 l bench-top bioreactor operated in continuous mode (D = 0.12 h(-1)). The repeatability of biofilm formation was tested by comparing five bioprocesses with Rhodotorula mucilaginosa, a strain isolated from washing machines. The amount of biofilm formed after 6 days post inoculation was 83 μg cm(-2) protein, 197 μg cm(-2) polysaccharide and 6.9 × 10(6) CFU cm(-2) on smooth polypropylene surfaces. Roughening the surface doubled the amount of biofilm but also increased its spatial variability. Plasma modification of polypropylene significantly reduced the hydrophobicity but did not enhance cell attachment. The biofilm formed on polypropylene coupons could be used for sanitation studies.

Characterization of Microbial Communities in Household Washing Machines

“…Previous studies could show that organisms that were isolated from biofilms from washing machines are more tolerant to chemical detergents compared to control strains [8,15]. For this reason potential drug-resistant organisms, which have been identified in the domestic environment, imply a potential health risk due to cross-contaminations during the washing process.…”

Consortia formed by yeasts and acetic acid bacteria Asaia spp. in soft drinks

“…The high hydrophobicity of Rhodotorula cells in M2 medium (with additional supplementation with yeast extract) may be connected to the accumulation of extracellular substances on the yeast cell surface. Gattlen et al ( 2011 ) reported that biofilm formed by R. mucilaginosa cells over 6 days, isolated from washing machines, also contained proteins and polysaccharides.…”

Yeast biofilm in food realms: occurrence and control

“…In beer, yeast biofilms constitute a negative phenomenon. In breweries, yeast can form biofilms colonizing new surfaces or existing fungal or bacterial biofilms (Gattlen et al 2011 ). In particular, yeasts have a high impact on alcohol-free beer and beer-mixed beverages, where they can be responsible for up to 90% of the spoilage incurred (Riedl et al 2019 ).…”