Proteome changes during yeast-like and pseudohyphal growth in the biofilm-forming yeast Pichia fermentans

Abstract

The Pichia fermentans strain DISAABA 726 is a biofilm-forming yeast that has been proposed as biocontrol agent to control brown rot on apple. How ever, when inoculated on peach, strain 726 shows yeast-like to pseudohyphal transition coupled to a pathogenic behaviour. To identify the proteins potentially involved in such transition process, a comparative proteome analysis of P. fermentans 726 developed on peach (filamentous growth) vs apple (yeast-like growth) was carried out using two-dimensional gel electrophoresis coupled with mass spectrometry analysis. The proteome comparison was also performed between the two different cell morphologies induced in a liquid medium amended with urea (yeast-like cells) or methionine (filamentous cells) to exclude fruit tissue impact on the transition. Seventy-three protein spots showed significant variations in abundance (±twofold, p < 0.01, confidence intervals 99 %) between pseudohyphal vs yeast-like morphology produced on fruits. Among them, 30 proteins changed their levels when the two morphologies were developed in liquid medium. The identified proteins belong to several pathways and functions, such as glycolysis, amino acid synthesis, chaperones, and signalling transduction. The possible role of a group of proteins belonging to the carbohydrate pathway in the metabolic re-organisation during P. fermentans dimorphic transition is discussed.

Analysis of extracellular vesicles produced in the biofilm by the dimorphic yeast Pichia fermentans

“…In our experiments P. fermentans in YCM grows in fermentative and osmotic conditions (Fiori et al, 2012;Maserti et al, 2015) which cause hypoxic stress (Chen et al, 2015) and strongly reduce elasticity of cell walls to protect the plasma membrane from rupture (Ene et al, 2015). These parameters play a decisive role in controlling the pore size and could control the EV size.…”

“…The yeast cell wall pore size has been reported to respond to environmental stimuli and to increase up to 400 nm under restrictive nutritional conditions in order to enhance nutrients uptake (de Souza Pereira & Geibel, ). In our experiments P. fermentans in YCM grows in fermentative and osmotic conditions (Fiori et al, ; Maserti et al, ) which cause hypoxic stress (Chen et al, ) and strongly reduce elasticity of cell walls to protect the plasma membrane from rupture (Ene et al, ). These parameters play a decisive role in controlling the pore size and could control the EV size.…”

Biocontrol yeasts: mechanisms and applications

“…However, the molecular underpinnings of the process and the composition of different biofilms (e.g., cell differentiation, multispecies biofilms) have only been studied in detail for Pichia fermentans . This species proved particularly intriguing in this respect, because biofilm formation in apple wounds protects against postharvest diseases, while on peaches P. fermentans switches from the yeast-like to the hyphal growth form and causes rapid decay of inoculated fruits in the absence of a plant pathogen (Fiori et al 2012; Giobbe et al 2007; Maserti et al 2015; Sanna et al 2012, 2013). Based on this “Jekyll & Hyde” pathogenic behaviour of P. fermentans on peach fruit, the capability to differentiate hyphae and pseudohyphae under particular growth conditions (e.g., depending on the nitrogen source) has been proposed as a potential biohazard factor for biocontrol yeasts (Giobbe et al 2007).…”

Increase in antioxidant enzyme activity, stress tolerance and biocontrol efficacy of Pichia kudriavzevii with the transition from a yeast-like to biofilm morphology

“…It was initially reported that this yeast strain in a yeast-like form was capable of inhibiting brown rot on apple fruit, but formed pseudohyphae on peach fruit and caused fruit decay (Giobbe et al, 2007). Additional studies were conducted to identify genes by suppressive subtractive hybridization (Fiori et al, 2012;Sanna et al, 2014) and proteins by proteome analysis (Maserti et al, 2015) involved in the morphological change of this yeast strain. To the best of our knowledge, however, little information is available on the relationship between the morphological change and stress tolerance of antagonistic yeasts.…”