Influence of Single Nitrogen Compounds on Growth and Fermentation Performance ofStarmerella bacillarisandSaccharomyces cerevisiaeduring Alcoholic Fermentation

Abstract

Nitrogen is among the essential nutriments that govern interactions between yeast species in the wine environment. A thorough knowledge of how these yeasts assimilate the nitrogen compounds of grape juice is an important prerequisite for a successful co- or sequential fermentation. In the present study, we investigated the efficiency of 18 nitrogen sources for sustaining the growth and fermentation of two Starm. bacillaris strains displaying metabolic properties, compared to the reference yeast S. cerevisiae. The analysis of growth and fermentation parameters provided a comprehensive picture of Starm. bacillaris preferences with respect to nitrogen sources for sustained growth and fermentation. Important differences were observed in S. cerevisiae regarding rates, final population and CO2 production. In particular, Lys and His supported substantial Starm. bacillaris growth and fermentation contrary to S. cerevisiae, while only 3 nitrogen sources, Arg, NH4+ and Ser, promoted S. cerevisiae growth more efficiently than that of Starm. bacillaris strains. Furthermore, Starm. bacillaris strains displayed a higher fermentative activity than S. cerevisiae during the first phase of culture with Gly or Thr, when the former species consumed solely fructose. Finally, no correlation has been shown between the ability of nitrogen sources to support growth and their fermentation efficiency. The specificities of Starm. bacillaris regarding nitrogen sources preferences are related to its genetic background, but further investigations are needed to elucidate the molecular mechanisms involved. These data are essential elements to be taken into account in order to make the best use of the potential of the two species.IMPORTANCE Mixed fermentations combining non-Saccharomyces and S. cerevisiae strains are increasingly implemented in the wine sector as they offer promising opportunities to diversify the flavour profile of end-products. However, competition for nutrients between species can cause fermentation problems, which is a severe hindrance to the development of these approaches. With the knowledge provided in this study on the nitrogen preferences of Starm. bacillaris, winemakers will be able to set up a nitrogen nutrition scheme adapted to the requirement of each species during mixed fermentation, through must supplementation with relevant nitrogen compounds. This will prevent nitrogen depletion or competition between yeasts for nitrogen sources, and consequently potential issues during fermentation. The data of this study highlight the importance of an appropriate nitrogen resource management during co- or sequential fermentation for fully exploiting the phenotypic potential of non-Saccharomyces yeasts.

Influence of nitrogen status on fermentation performances of non- Saccharomyces yeasts: a review

“…On the other hand, however, differences were also noted. Proline, an amino acid inaccessible for S. cerevisiae under anaerobic conditions, was identified as a preferred nitrogen source for Lachancea thermotolerans Viniflora  Concerto  , Candida zemplinina CszB4, H. uvarum HuB10, S. bacillaris FC54, and S. bacillaris MUT5705 [15][16][17]. Different nitrogen uptake systems therein, compared to S. cerevisiae, though not yet revealed for most non-Saccharomyces yeasts, are proposed based on such findings.…”

Unique volatile chemical profiles produced by indigenous and commercial strains of <i>Saccharomyces uvarum</i> and <i>Saccharomyces cerevisiae</i> during laboratory-scale Chardonnay fermentations

“…Yeast growth (CFU/mL) was not measured in this experiment, thus further research is needed to determine if the growth rate was indeed a factor in the different fermentation performances observed among these yeast strains. Differences in fermentation kinetics and growth rates among the different strains of S. cerevisiae and S. uvarum could potentially be attributed to differences in their abilities to use ammonia and different amino acids (Englezos et al, 2021;Minebois et al, 2020), but more research is needed to determine if this is the case. Surprisingly, two S. uvarum strains, one at 15 °C and the other at 25 °C, had similar fermentation kinetics to that of EC-1118.…”

Amino Acids Drive the Deterministic Assembly Process of Fungal Community and Affect the Flavor Metabolites in Baijiu Fermentation

“…First, amino acids are the main nutrients assimilated by microorganisms, after carbon compounds. The growth and fermentation kinetics of microorganisms greatly depend on both the quantity and quality of amino acids ( 10 – 12 ). Second, some amino acids are the precursors for the synthesis of volatile compounds that significantly contribute to the flavor and aroma of products.…”