Predominant Yeasts During Artisanal Mezcal Fermentation and Their Capacity to Ferment Maguey Juice

Abstract

Artisanal mezcal is produced by the natural fermentation of maguey juice, which frequently results in a process that becomes stuck or is sluggish. Using selected indigenous starter inoculums of Saccharomyces and non-Saccharomyces yeasts is considered beneficial in overcoming these problems and thereby preserving the essence of the artisanal process. In this work, three hundred and four yeast isolates were recovered from 17 distilleries and then grouped by the ARDRA analysis, their restriction profiles were clustered in 15 groups. Four of them included 90% of all isolates, and these were identified using the sequence of the D1/D2 domain of the large-subunit rDNA. Pichia kudriavzevii, Pichia manshurica, Saccharomyces cerevisiae, and Kluyveromyces marxianus were detected as predominant species. Both species belonging to the Pichia genus were detected in 88% of the distilleries, followed by S. cerevisiae (70%) and K. marxianus (50%). In order to evaluate the fermentative capacity, one strain of each species was assessed in a pure and mixed culture in two culture media, filtered maguey juice (MJ) and maguey juice including its bagasse (MJB). Findings demonstrated that non-Saccharomyces yeast presented better growth than that of S. cerevisiae. K. marxianus PA16 was more efficient for ethanol production than S. cerevisiae DI14. It produced 32 g/L of ethanol with a yield of 0.47 g/g and efficient of 90%. While, P. kudriavzevii produced more ethyl acetate (280 mg/L) than the others species. All fermentations were characterized by the presence of isobutyl and isoamyl alcohol. The presence of K. marxianus in a mixed culture, improved the ethanol production and volatile compounds increased using co-cultures.

Rational Selection of Mixed Yeasts Starters for Agave Must Fermentation

“…These non-Saccharomyces yeasts have become increasingly important, since they contribute to the production of compounds that provide the aromatic characteristic to Agave beverages (Amaya- Delgado et al, 2013;González-Robles et al, 2015) and wine (Tufariello et al, 2021). The co-existence of different species or strains in the mezcal fermentative process can have positive effects such as the increase of the hexose consumption and alcohol yields (Nolasco-Cancino et al, 2018). The non-Saccharomyces yeasts have shown potential as starters for the Agave alcoholic beverage industry (Arrizon et al, 2006;Amaya-Delgado et al, 2013;Segura-García et al, 2015;De la Torre-González et al, 2017;Nolasco-Cancino et al, 2018).…”

“…The co-existence of different species or strains in the mezcal fermentative process can have positive effects such as the increase of the hexose consumption and alcohol yields (Nolasco-Cancino et al, 2018). The non-Saccharomyces yeasts have shown potential as starters for the Agave alcoholic beverage industry (Arrizon et al, 2006;Amaya-Delgado et al, 2013;Segura-García et al, 2015;De la Torre-González et al, 2017;Nolasco-Cancino et al, 2018). However, most of the reported kinetics of these consortia of Saccharomyces and non-Saccharomyces yeasts have been analyzed for wine (grape juice), where both yeast populations maintain similar growth rates during the first phases (2-3 days) of fermentation, and then present a reduction in the non-Saccharomyces yeast number as the fermentation time progresses (Pina et al, 2005).…”

Comparative NMR Metabolomics Profiling between Mexican Ancestral & Artisanal Mezcals and Industrialized Wines to Discriminate Geographical Origins, Agave Species or Grape Varieties and Manufacturing Processes as a Function of Their Quality Attributes

“…Limitations of the 1 H-NMR / MSA mezcals' discriminant analysis are contrasted with the first-time reported OPLS-DA results obtained for industrialized Mexican wines, whereas the MSA inputs of both systems (NMR acquisition and preprocessing routines) were carefully taken at equivalent For wines, one-dimensional 1 H NMR signal assignment (Table 3) present accurate agreements with respect to previous reports, comprising the typical set of discriminant metabolites such as caftaric acid, sorbic acid, fructose, acetoine, citric acid, malic acid, arginine isoleucine and valine (positive loadings in the present NMR data matrix, see Figure 6), as well as shikimic acid, fumaric acid, glucose, GABA, acetate and lactic acid valine (negative loadings in the present NMR data matrix, see Figure 6). For mezcals, the current report presents the first efforts of a one-dimensional 1 H NMR profiling based on the chemical shifts (δ, ppm), proton homonuclear scalar couplings (J, Hz) and signal multiplicity assignments of discriminant metabolites' NMR resonances (Table 4), in comparison to the few available works reporting the major components in mezcals-produced from different agave species with chromatographic analysis [3,26,47]. All identified furane derivatives (2-furfural, 5-substituted furanaldehyde, 2-furoic acid and (furan-2-yl)-methanol), acetaldehyde, aromatic moieties (phenethyl alcohol and phenethyl acetate), ethyl acetate, and n-butanol species, present negative loadings as the fingerprint responsible for OPLS-DA regional, species, and manufacturing processes' discriminations.…”

“…In contrast, few reports have emerged comprising the use of NMR/MSA metabolomics for the profiling and/or targeting of North and Central Latin America agave spirits such as tequila or mezcal. Regarding mezcal, its manufacture involves harvesting, cooking, milling, yeast-free fermentation and double distillation of agave’s hearts [ 23 , 24 , 25 , 26 ], in agreement with its Nahuatl etymology: Metlixcalli which means oven-cooked agaves. Certified mezcals are classified by local regulations by at least three general classes: industrial, artisanal, and ancestral mezcal [ 27 ].…”

Draft Genome Sequence of the Yeast Pichia manshurica YM63, a Participant in Secondary Fermentation of Ishizuchi-Kurocha, a Japanese Fermented Tea

“…Pichia manshurica (phylum Ascomycota, subphylum Saccharomycotina) is a common yeast found in fermented animal feed and foods such as fermented maguey juice (1), a traditional beverage of Burkina Faso (2), wines (3), and silages (4). Ishizuchi-kurocha is a traditional fermented tea in Shikoku Island, Japan (5).…”