VII International Conference on Environmental, Industrial and Applied Microbiology - BioMicroWorld2017 Madrid(Spam), I-20 October 2017
Genetic
i
mproveme
n
t
for techno
l
og
i
cal
traits
of
non-Saccharomyces
wine
yeasts
Andrea Caridi, Rossana Sidari and Sabrina Voce
Department ofAgraria, Mediterranea University ofReggio Calabria, ViaFeodiVitosin, 89122Reggio Calabria, Italy
While Saccharomyces cerevisiae is the main species of wine production, other species have significant roles;
interactions between thedifferent species and their impacts onprocess efficiency and product quality need to be identified and evaluated [I]. At present, there isa growing demand for selected strains of non-Saccharomyces wine yeasts suitable to be used in association with Saccharomyces cerevisiae forgrape juice fermentation [2J.
Wine yeasts of the genus Hanseniaspora [3J and Schizosaccharomyces [4J perform alcoholic fermentation
producing notably amounts ofacetic acid and hydrogen sulphite and -forthese attributes -usually they are not
easily suitable inwinemaking. Since they are ascosporogenous yeasts [5], asforSaccharomyces they could be
processed via classical methods, such as micromanipulation, in order to improve their technological characteristics. The aim of thiswork was 10consider the implications ofa new technique -easy, cheap and fas
t-able to improve by genetic way technological traits intvnv-Soccharomyces ascospore-producing wine yeasts. The
new technique essentially consists in: I) inducing the production of ascospore using acetate agar, Gorodkowa agar, and Sabouraud agar; 2) inducing the lysis of the asci using zymolyase; 3) plating the serial dilutions in
nutrient medium; 4) based on themorphological characteristics of colony and cell, collecting the descendants; 5) testing hydrogen sulphite andacetic acid production on BiGGY agar and Chalk agar; 6)selecting the beststrains. A total of 12strains of Schizosaccharomyces spp. and 35 strains of Hanseniaspora spp. were tested in order to identify strains able to produce enough amount of ascospores. Then, they were processed using both the new
technique and the micromanipulation technique. Indetails, using the new technique atotal of 35 descendants of
Schizosaccharomyces and 29 descendants of Hanseniaspora were collected. An interesting biodi versity was
observed both onBiGGY agar andChalk agar, so validating the effectiveness ofthe proposed technique.
Keywords: ascospore;genetic improvement: non-Saccharomyces; technological trait;wine yeast.
References
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[2] Domizio P,Romani C, Lencioni L, Comitini F,Gobbi M,Mannazzu I,Ciani M(2011) Outlining a future forn
on-Saccharomyces yeasts: Selection of putative spoilage winc strainstobeused inassociation with Saccharomyces ccrevisiae for grapejuice fcrmentation.lnt J FoodMicrobiol\47:170-\80.
[3]VianaF,GilJV,Genoves S,Valles S,Manzanares P (2008) Rational selection of non-Saccharomyces wine yeasts for mixedstarters basedonester fonmationand enologiealtraits. FoodMierobioI25:778-785.
[4] Suarez-Lope JA, Palomero F,Benito S,Calderon F,Morata A (2012) Oenological versatility ofSchizosaccharomyces spp.EurFood ResTechnol235:375-383.
[5] Kurtzman
