Identification of novel GAPDH-derived antimicrobial peptides secreted by Saccharomyces cerevisiae and involved in wine microbial interactions

Abstract

Saccharomyces cerevisiae plays a primordial role in alcoholic fermentation and has a vast worldwide application in the production of fuel-ethanol, food and beverages. The dominance of S. cerevisiae over other microbial species during alcoholic fermentations has been traditionally ascribed to its higher ethanol tolerance. However, recent studies suggested that other phenomena, such as microbial interactions mediated by killer-like toxins, might play an important role. Here we show that S. cerevisiae secretes antimicrobial peptides (AMPs) during alcoholic fermentation that are active against a wide variety of wine-related yeasts (e.g. Dekkera bruxellensis) and bacteria (e.g. Oenococcus oeni). Mass spectrometry analyses revealed that these AMPs correspond to fragments of the S. cerevisiae glyceraldehyde 3-phosphate dehydrogenase (GAPDH) protein. The involvement of GAPDH-derived peptides in wine microbial interactions was further sustained by results obtained in mixed cultures performed with S. cerevisiae single mutants deleted in each of the GAPDH codifying genes (TDH1-3) and also with a S. cerevisiae mutant deleted in the YCA1 gene, which codifies the apoptosis-involved enzyme metacaspase. These findings are discussed in the context of wine microbial interactions, biopreservation potential and the role of GAPDH in the defence system of S. cerevisiae.

Growth kinetics and physiological behavior of co-cultures of Saccharomyces cerevisiae and Kluyveromyces lactis , fermenting carob sugars extracted with whey

“…The killer toxin did not seem to be produced. Toxic peptides that had been described in wineries [10,11] could be present. Our results, without completely discarding other possibilities, point to the great importance of oxygen for the performance and even viability of K. lactis.…”

“…Several factors have been referred to justify this early death of the non-Saccharomyces species (NS) in wineries, such as the high levels of ethanol and organic acids, low pH values, depletion of certain nutrients, as well as other yeast-yeast interactions (e.g. killer toxins) [10,11]. The limited oxygen availability is another factor mentioned.…”

Impact of inhibitory peptides released by Saccharomyces cerevisiae BDX on the malolactic fermentation performed by Oenococcus oeni Vitilactic F

“…Albergaria et al (2010) showed that S. cerevisiae CCMI 885 started to secrete three antifungal peptides of about 6, 4.5 and 4 kDa at the end of the AF exponential growth phase (day 2) with a gradual increase of their concentration during the stationary growth phase (days 4 and 7). Later on, Branco et al (2014) who used the same yeast strain demonstrated that these peptides were also active against the growth of O. oeni and corresponded to GAPDH-derived peptides of 1.6 kDa. They suggested that the peptides were released by apoptotic yeast cells during the stationary phase.…”

“…forming membrane pores and facilitating the entry of SO 2 inside the cells thus leading to the bacterial death and arrest of MLF. The mechanism of action of the GAPDH-derived peptides identified by Branco et al (2014) and that inhibited the growth of O. oeni was not elucidated. In addition no data concerning the malate consumption was shown.…”

“…Mendoza et al (2010) showed that S. cerevisiae mc2 released a proteinaceous compound presenting a MW between 3 and 10 kDa that inhibited the growth of O. oeni X 2 L but not its ability to consume L-malic acid. Finally, Branco et al (2014) showed that S. cerevisiae CCMI 885 secreted antimicrobial peptides (AMP) that were active against a wide variety of wine-related yeasts in addition to O. oeni. However, only the microbial growth was evaluated.…”