Molecular Wine Microbiology

MOLECULAR WINE MICROBIOLOGY Edited by ALFONSO V. CARRASCOSA ROSARIO MUN˜ OZ RAMO´ N GONZA´ LEZ AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Academic Press is an imprint of Elsevier Academic Press is an imprint of Elsevier 32 Jamestown Road, London, NW1 7BY, UK 30 Corporate Drive, Suite 400, Burlington, MA 01803, USA 525 B Street, Suite 1800, San Diego, CA 92101-4495, USA First edition 2011 Copyright Ó 2011 Elsevier Inc. All rights reserved Translation by Anne Murray and lain Patten No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, mechanical, photocopying, recording or otherwise without the prior written permission of the publisher Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone (+44) (0) 1865 843830; fax (+44) (0) 1865 853333; email: [email protected]. Alternatively, visit the Science and Technology Books website at www.elsevierdirect.com/rights for further information Notice No responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. Because of rapid advances in the medical sciences, in particular, independent verification of diagnoses and drug dosages should be made British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress ISBN: 978-0-12-375021-1 For information on all Academic Press publications visit our website at www.elsevierdirect.com Typeset by TNQ Books and Journals Printed and bound in the United States of America 11 12 13 14 15 10 9 8 7 6 5 4 3 1 Preface The publication of Louis Pasteur’s Me´moire It is hoped that Molecular Wine Microbiology sur la fermentation alcoolique in 1857 has come to will be a useful tool for researchers and educa- represent a milestone in the history of science tors working in both the private and public and its applications, as it marked the beginning sectors. Above all, however, it will be a valuable of a growing fascination with the biology of resource for those starting out on their fasci- wine microorganisms among researchers world- nating journey through the world of wine wide. Since then, unprecedented improvements microbiology. in winemaking processes have gone hand in Coordinated by Alfonso V. Carrascosa, hand with the development of modern microbi- Rosario Munõz, and Ramoń Gonza´lez from the ology, and it would now be impossible to under- Spanish National Research Council (CSIC), this stand the continuing progress made in the wine book brings together contributions from a range industry without taking into account the impact of experts on the microbiology of wine working of advances in microbiological research. in universities, research centers, and industry. A greater understanding of the microbiology of wine holds the key to critical issues affecting the industry, such as the management of safety and quality. For instance, by identifying and Translation by Anne Murray and lain Patten gaining a better understanding of the molecular mechanisms underlying the growth of microor- The editors would like to acknowledge ganisms that cause wine spoilage or pose a the excellent translation of the Spanish text. The threat to consumer health, winemakers will be translators have been able to capture all the better positioned to control and even eradicate nuances of the original, using accurate wine- them during the production process. making English terms. vii CHAPTER 1 Saccharomyces Yeasts I: Primary Fermentation Agustıń Aranda 1, Emilia Matallana 1,2, Marcel$lı´ del Olmo 2 1 Departamento de Biotecnologıá, Instituto de Agroquı´mica y Tecnologıá de Alimentos, CSIC, Valencia, Spain and 2 Departament de Bioquı´mica i Biologia Molecular, Facultat de Cie`ncies Biolo`giques, Universitat de Vale`ncia, Valencia, Spain OUTLINE 1. Yeasts of Interest in Wine Production 2 2.2.3. pH 9 1.1. Yeast Flora on the Grape, in the Winery, 2.2.4. Clarification 9 and in the Must 2 2.2.5. Carbon Dioxide 9 1.2. Morphology and Cellular Organization of 2.3. Yeast Growth and Fermentation Kinetics 9 Yeasts 3 2.4. Biochemistry of Fermentation 10 1.3. Genetic Characteristics of Wine Yeasts 4 2.4.1. Alcoholic Fermentation 11 2.4.2. Nitrogen Metabolism 12 2. Growth Characteristics of Saccharomyces 2.5. The Importance of Yeast Metabolism in Yeasts During Fermentation 4 Wine Aroma 14 2.1. Must Composition 4 2.1.1. Sugars 5 3. Gene Expression During Fermentation 17 2.1.2. Organic Acids 5 3.1. Glycolytic Genes 18 2.1.3. Nitrogenous Compounds 5 3.2. Osmotic Stress-response Genes 19 2.1.4. Polyphenols 7 3.3. Genes Induced During the Stationary 2.1.5. Mineral Salts 7 Phase 20 2.1.6. Lipids 7 3.4. Gene Expression in Wine Yeasts Exposed 2.1.7. Inhibitors 7 to Specific Stress Conditions 22 2.2. Physical Parameters of Fermentation 8 4. Genetic Improvement of Yeast Efficiency 2.2.1. Temperature 8 During Fermentation 23 2.2.2. Aeration 8 Molecular Wine Microbiology Doi: 10.1016/B978-0-12-375021-1.10001-3 1 Copyright Ó 2011 Elsevier Inc. All rights reserved. 2 1. SACCHAROMYCES YEASTS I: PRIMARY FERMENTATION 1. YEASTS OF INTEREST IN WINE numbers. This microflora can be affected by PRODUCTION a wide variety of factors, principally temperature, rainfall, altitude, ripeness of the crop, and 1.1. Yeast Flora on the Grape, in the use of fungicides (Boulton et al., 1996). The flora Winery, and in the Must associated with winery equipment is largely made up of S. cerevisiae (Fleet & Heard, 1993; The fermentation of grape must is a complex Fleet, 2007; Martini & Vaughan-Martini, 1990), microbiological process that involves interac- though species of the genera Brettanomyces, tions between yeasts, bacteria, and filamentous Candida, Hansenula, Kloeckera, Pichia, and Toru- fungi (Fleet, 2007; Fugelsang & Edwards, laspora have also been isolated. 2007). Yeasts, which play a central role in the The yeasts present in the must during the first winemaking process, are unicellular fungi that few hours after filling the tanks belong to the reproduce by budding. Most yeasts belong to same genera as those found on the grapes, the phylum Ascomycota on the basis of their predominantly Hanseniaspora/Kloeckera. In these sexual development. In these organisms, the spontaneous vinification conditions, Saccharo- zygote develops within a sac-like structure, the myces yeasts (mainly S. cerevisiae) begin to ascus, while the nucleus undergoes two meiotic develop after around 20 h and are present divisions, often followed by one or more mitotic alongside the grape-derived yeast flora. After 3 divisions. A wall forms around each daughter or 4 d of fermentation, Saccharomyces yeasts nucleus and its surrounding cytoplasm to predominate and are ultimately responsible for generate four ascospores within the ascus. The alcoholic fermentation (Ribe´reau-Gayon et al., ascus then ruptures and releases the ascospores, 2006). This change in the yeast population is which can germinate and produce new vegeta- linked to the increasing presence of ethanol, tive cells. Although thousands of yeast species the anaerobic conditions, the use of sulfites have been identified, only 15 correspond to during harvesting and in the must, the concen- wine yeasts (Ribe´reau-Gayon et al., 2006). tration of sugar, and the greater tolerance of Traditionally, wine has been produced using high temperatures shown by S. cerevisiae yeast strains found on the surface of grapes compared with other yeasts (Fleet & Heard, and in the winery environment. The yeasts 1993; Fleet, 2007). S. cerevisiae comprises reach the grapes by wind and insect dispersal numerous strains with varying biotechnological and are present on the wines from the onset of properties (Ribe´reau-Gayon et al., 2006). The fruit ripening (Lafon-Lafourcade, 1983). The importance of using genetic techniques to iden- predominant species on the grape is Kloeckera tify and characterize the different species and apiculata, which can account for more than 50% strains of yeast that participate in fermentation of the flora recovered from the fruit (Fugelsang should not be underestimated. This is consid- & Edwards, 2007). Other species of obligate ered further in Chapter 5, which addresses the aerobic or weakly fermentative yeasts with taxonomy of wine yeasts. very limited alcohol tolerance may also be Currently, the usual strategy employed in found in lesser proportions. These belong to winemaking involves inoculation of the must the genera Candida, Cryptococcus, Debaryomyces, with selected yeasts in the form of active dried Hansenula, Issatchenkia, Kluyveromyces, Metschni- yeast. This practice, which emerged in the kowia, Pichia, and Rhodotorula (Fleet & Heard, 1970s, shortens the lag phase, ensures rapid 1993; Ribe´reau-Gayon et al., 2006). The fermen- and complete fermentation of the must, and tative species Saccharomyces cerevisiae and helps to create a much more reproducible final Saccharomyces bayanus are present in limited product (Bauer & Pretorius, 2000; Fleet & Heard, YEASTS OF INTEREST IN WINE PRODUCTION 3 1993). The selection of wine yeasts with specific with specific wine-growing regions (Lafon- genetic markers provides a system for the Lafourcade, 1983; Snow, 1983). precise monitoring of the growth of particular strains during fermentation. Analyses of this 1.2. Morphology and Cellular type have shown that fermentation is driven Organization of Yeasts mainly by inoculated yeasts (Delteil & Aizac, 1988), although these sometimes become only Saccharomyces yeast cells have a rigid cell wall partially established (Esteve-Zarzoso et al., that allows them to resist the changes in osmotic 1999).

Load more