Agricultural and wine microbiology - MICROBIOLOGIA ENOLOGICA (2019/2020)

Course code
4S003186
Credits
6
Academic sector
AGR/16 - AGRICULTURAL MICROBIOLOGY
Language of instruction
Italian
Teaching is organised as follows:
Activity Credits Period Academic staff Timetable
Teoria 5 II semestre Sandra Torriani

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Laboratorio [Laboratorio - esercitazioni 1° turno] 1 II semestre Sandra Torriani

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Laboratorio [Laboratorio - esercitazioni 2° turno] 1 II semestre Sandra Torriani

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Learning outcomes

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MM: Teoria
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The module will provide the instruments needed to acquire theoretical and practical skill on the biotechnological aspects of fermentation and transformation of must and wine, and on the stability of the final product. These skills are of great importance to understand, manage, and optimize the activities of yeasts and bacteria in relation to the characteristics of the must and the wine to be obtained, as well as of the productive process applied.
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MM: Laboratorio
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Laboratory exercises to acquire competence on classical and innovative analytical methods.

Syllabus

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MM: Teoria
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The microorganisms of oenological interest: yeasts and bacteria in winemaking. The yeasts: classification, metabolism, reproduction, genetics. The must as a substrate for microbial development. The alcoholic and malolactic fermentations. The principal and secondary products of fermentation. The lactic acid bacteria: definition and classification. The malolactic fermentation: effects on the sensory characteristics and the wholesomeness of wines. Other microorganisms of oenological interest: acetic acid bacteria and mould. Wine spoilage of microbial origin. Definition and characteristics of spoilage microorganisms. Production of biogenic amines, etilcarbammate and ochratoxin. Microbial ecology: the spontaneous fermentation of grape must. The controlled fermentations. Starter cultures of yeasts and malolactic bacteria for wine. Clonal selection of yeasts, genetic improvement, selection of technological and qualitative characteristics, autolytic capacity. Clonal selection of malolactic bacteria, selection of technological and qualitative characteristics. Use of microbial inoculants in oenology. Working conditions, induction / arrest of alcoholic fermentation. Microbial interactions and wine quality. Methods for the isolation, identification and technological characterization of yeasts and malolactic bacteria. Traditional methods. Direct and indirect rapid methods. Molecular techniques.
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MM: Laboratorio
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- Microscopy applied to microorganisms of oenological interest (elliptic and apiculate yeasts, lactic bacteria, acetic bacteria, molds). - Analysis of the microbiological quality of oenological starter. Yeast isolation. - Physiological and technological tests on isolates. - DNA extraction and genetic typing of Saccharomyces cerevisiae strains. - Microvinification trials and monitoring of malolactic fermentation.

Assessment methods and criteria

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MM: Teoria
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The assessment of learning, for both attending and non-attending students, will be done at the end of the module through a written test of approximately 75 minutes, during which text books, notes, and other tools are not admitted. The test consists of 8 open questions for each of which a maximum score of 2 points will be assigned, and 20 multiple choice questions, each associated with a maximum of 1 point. The examination will be considered positive if at least 18 points will be assigned to the candidate. To gain access to the test, at least the previous day of the test, the candidate must submit a report on the practical activities carried out in the laboratory; this report will have a maximum score of 2 points. Scores higher than 31 will result in the "laude". It is possible to view the performed test and ask for clarification. In case the written test is not passed, the assessment of learning will be carried out with an oral exam which consists of three or four questions posed to each candidate. The exam lasts about 30 minutes. Both written and oral examinations are aimed to assess and verify the skills and knowledge acquired in the issues addressed throughout all the course program. The course of Agricultural and Wine Microbiology will be considered positive if the score of at least 18 points will be reached in both the modules and the final score will derive from the arithmetic mean of the scores obtained in the two modules.
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MM: Laboratorio
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Students have to prepare a report on the practical activities carried out in the laboratory; this report will be provided at least the day before the written test, and will be evaluated with a maximum score of 2 points. This score will be added to the mark obtained in the exam on the contents of the course.

Reference books
Activity Author Title Publisher Year ISBN Note
Teoria Suzzi G. & Tofalo R. Microbiologia enologica (Edizione 2) Edagricole 2018 978-88-506-5557-1