Molecular and Phenotypic Characterization of Metschnikowia pulcherrima Strains from Douro Wine Region

Abstract

Some non-Saccharomyces yeasts, including Metschnikowia pulcherrima, have been proposed as selected starters due to their contribution for the overall aroma and chemical profiles of wines. In this work, we aimed to evaluate the genetic and phenotypic diversity of Metschnikowia pulcherrima strains isolated from different locations of Douro Wine Region, and to explore their potential as co-adjuncts of S. cerevisiae in alcoholic fermentation. For that purpose, a set of 64 M. pulcherrima isolates were used. Polymerase chain reaction (PCR) fingerprinting with M13 primers demonstrated to be an efficient tool in intraspecific discrimination of M. pulcherrima strains. No significant associations were found between genotypic profiles and either geographical origin or winery. The isolates were screened for their stress resistance ability (ethanol, SO 2 , chitosan, copper, H 2 O 2 , and Grape Juice Medium), aroma-related activities (resistance to 5, 5 , 5 -trifluor-D, L-leucine and cerulenin and β-glycosidase, β-lyase and sulfite-reductase activities) as well as other relevant technological proprieties (protease activity and biogenic amines production). M. pulcherrima response to the different enological traits evaluated was greatly strain-dependent. The most discriminant features were the ability of the strains to grow in Grape-Juice Medium (GJM) and sulfite-reductase, and their β-lyase and protease activities. The enological potential of a selected M. pulcherrima strain in mixed-culture with S. cerevisiae was also assessed in natural grape-juice of a local variety, under two nitrogen regimes. M. pulcherrima proved to be promising for future industrial application as a co-starter, lowering ethanol, acetic acid and, reported here for the first time, lowering hydrogen sulfide levels in the wines.

Identification and Characterization of Non-Saccharomyces Species Isolated from Port Wine Spontaneous Fermentations

“…orientalis and half of the L. thermotolerans strains (B9, F7, and F8), produced low levels of acetic acid, while the other half of the L. thermotolerans strains did not produce this acid under the experimental conditions. Not all M. pulcherrima strains produced acetic acid, in agreement with previous studies [71,72]. Interestingly not all H. uvarum strains produced high levels of acetic acid, contrary to previous findings [59].…”

Achieving a high‐density oleaginous yeast culture: Comparison of four processing strategies using Metschnikowia pulcherrima

“…Metschnikowia pulcherrima is a relatively under‐explored oleaginous yeast (Abeln et al, ; Canonico et al, ; Santomauro, Whiffin, Scott, & Chuck, ), however, the yeast is an ideal organism for industrial biotechnology due to: elevated inhibitor tolerance: specifically, formic acid, acetic acid, furfural, hydroxymethylfurfural (HMF) in concentrations up to 10 g L −1 (Fan et al, ; Sitepu, Selby, Lin, Zhu, & Boundy‐Mills, ); a wide substrate spectrum: a range of C 5 and C 6 monosaccharides and oligosaccharides (Abeln et al, ; Fan et al, ; Santomauro et al, ; Sitepu et al, ); production of an array of secondary metabolites: most prominently 2‐phenylethanol (2‐PE), a valuable fragrance compound (Abeln et al, ; Chantasuban et al, ); its antimicrobial activity: secretion of antimicrobial agents such as 2‐PE and iron sequestration through pulcherrimin production (Gore‐Lloyd et al, ; Krause et al, ; Oro, Ciani, & Comitini, ; Sipiczki, ; Türkel, Korukluoğlu, & Yavuz, ); being nonpathogenic: it is commonly used in wine fermentations as often found on grapes (Barbosa et al, ; Clemente‐Jimenez, Mingorance‐Cazorla, Martínez‐Rodríguez, Las Heras‐Vázquez, & Rodríguez‐Vico, ; Oro et al, ).…”

“…being nonpathogenic: it is commonly used in wine fermentations as often found on grapes (Barbosa et al, ; Clemente‐Jimenez, Mingorance‐Cazorla, Martínez‐Rodríguez, Las Heras‐Vázquez, & Rodríguez‐Vico, ; Oro et al, ).…”

Effects of Various Environmental Conditions on Pulcherrimin Production and Extracellular Enzyme Profiles of Metschnikowia pulcherrima

“…The extracellular enzyme activities of M. pulcherrima yeast strains are important for production of different esters and aroma during wine production. The pectinase, protease, glucanase, lichenase, β-glucosidase, cellulase, xylanase, amylase, sulphite reductase and lipase and β-lyase enzyme activities of M. pulcherrima yeast strains were previously reported [26], [27], [28], [29]. In our research we determine the extracellular enzyme profile of M. pulcherrima yeast strains qualitatively by using API-ZYM test.…”