Hyphal-like extension and pseudohyphal formation in industrial strains of yeasts induced by isoamyl alcohol

Abstract

Yeasts can produce pseudohyphae and hyphal-like extensions under certain growth conditions like isoamyl alcohol (IAA) induction, a chief constituent of fusel oil, which is a subproduct from the ethanolic fermentation. The morphology switch from yeast to a filamentous form can be troublesome to the process. In this work it was studied the influence of fusel alcohols, nitrogen sources (ammonium sulphate and leucine) and glifosate (a chemical maturator for sugar cane) added to a complex medium on some industrial strains of yeasts isolated from the fermentative process. Two industrial strains showed transition to hyphal-like extensions or pseudohyphae (clusters of cells) upon addition of IAA from 0.3 to 0.9% /v. The alterations were reversible when the yeasts were reinoculated in YEPD without IAA. Although pseudohyphae are a result of nitrogenlimited medium, we observed them as a result of IAA addition. No influence of the nitrogen source or isopropilic alcohol or glifosate was detected for any strain studied in the concentrations used.

Molecular and comparative genomic analyses reveal evolutionarily conserved and unique features of the Schizosaccharomyces japonicus mycelial growth and the underlying genomic changes

“…Since the environmental and stress factors have a strong impact on hyphae production (reviewed in Biswas et al 2007 ), we tested the effect of some culture factors on the S. japonicus mycelial growth. The presence of isoamyl-alcohol did not induce hyphal development in S. japonicus, unlike budding yeasts, instead it slightly decreased length of the hyphae (Ceccato-Antonini and da Silva 2002 ; Dickinson 1996 ). We also obtained different results from budding yeasts when we applied FeCl 3 supplementation in the medium.…”

Biotechnological implications of filamentation in Saccharomyces cerevisiae

“…Ceccato-Antonini and Silva (2002) observed filamentous structures in response to isoamyl alcohol for two industrial yeast strains from ethanolic fermentative processes using solid rich medium. A recent report has shown the feasibility of targeted gene deletion (MPK1) in industrial yeast strains, allowing the evaluation of specific genes upon filamentous growth (Vancetto and Ceccato-Antonini 2007).…”