Abstract
Thirty-three Kluyveromyces marxianus strains were tested for the ability to form biofilm and mat structures in YPD and whey and for cell surface hydrophobicity. To identify genes potentially involved in adhesion properties, a RT-qPCR analysis was performed. Eight strains were able to adhere on polystyrene plates in both media and formed a mature mat structure. These strains showed a different level of hydrophobicity ranging from 55 to 66% in YPD and from 69 to 81% in whey. Four K. marxianus orthologs genes (FLO11, STE12, TPK3, and WSC4), known from studies in other yeast to be involved in biofilm formation, have been studied. FLO11 and STE12 showed the highest fold changes in all conditions tested and especially in whey: 15.05 and 11.21, respectively. TPK3 was upregulated only in a strain, and WSC4 in 3 strains. In YPD, fold changes were lower than in whey with STE12 and FLO11 genes showing the highest fold changes. In mat structures FLO11 and STE12 fold changes ranged from 3.6–1.3 to 2–1.17, respectively. Further studies are necessary to better understand the role of these genes in K. marxianus adhesion ability.
Highlights
Many microorganisms can form multicellular, sessile, surface-bound assemblies known as biofilms
We focused on genes that are already known in S. cerevisiae to be involved in biofilm formation: FLO11 gene – in Kluyveromyces lactis it showed some similarities with S. cerevisiae YIR019C MUC1 GPI-anchored cell surface glycoprotein essential for pseudohyphal formation and invasive growth (Van Mulders et al, 2009; Legras et al, 2016); STE12 – the transcription factor activated by a MAP kinase signaling cascade and the activity of the gene is involved in mating or pseudohyphal/invasive growth pathways; TPK3 – involved in nutrient control of cell growth and division; WSC4 – involved in cell wall integrity and stress response
The others 25 strains were not able to adhere to polystyrene plates and to produce a mat structure, which was similar to negative control
Summary
Many microorganisms can form multicellular, sessile, surface-bound assemblies known as biofilms. Microorganisms able to form biofilm can shift between two different forms: planktonic cells in a free-living state, and sessile cells in a multicellular state (Andersen et al, 2014). The ability to form biofilm is strictly related to another multicellular development, the so-called mat structures. Mat is a structure composed of a complex of aggregated cells. It is formed of a network of multiple radial spokes originating from a central hub. This elaborate pattern is regulated by specific processes, depending on specific transcriptional programming, environmental signals, and cell– cell communication systems (Reynolds, 2006). Adhesion properties have mostly been described by the action of cell wall glicoproteins (Verstrepen and Klis, 2006; Goossens and Willaert, 2010; Moreno-García et al, 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
