B8282 - MICROBIOLOGIA APPLICATA ALLE PRODUZIONI ANIMALI

Learning outcomes

At the end of the course, students will have acquired knowledge of the principles of microbial biology and bacterial taxonomy, as well as the fundamentals of food microbiology. They will understand the role of the main microbial populations in the gastrointestinal tract of monogastric animals and ruminants, in foods of animal origin, and the basic concepts required to address food hygiene. Students will also be familiar with the microbiology of silage and the main fermentation processes involved in food transformation, particularly those underlying dairy and cured meat production.

Course contents

Overview: Scope of microbiology, general definitions. What is a microorganism. General composition and functions of the microbial cell. Eukaryotic and prokaryotic cells

Cell Structure: Morphology of bacterial cells; cell wall, peptidoglycan. Gram staining: Gram-positive and Gram-negative bacteria; outer membrane and periplasmic space of Gram-negative bacteria. Plasma membrane; membrane proteins and fluidity. External layers. Motility structures. Cytoplasm. Ribosomes. Endospore production. Morphology of the eukaryotic cell. Cell wall, chloroplasts, mitochondria. Nucleus and chromosomes. Endoplasmic reticulum, Golgi apparatus.

Growth: Culture media: definition, classification, preparation. Microorganism counting. Microbial growth curve: lag phase, exponential phase, stationary phase, and death phase.

Main Factors Influencing Microbial Growth: Temperature, pH, water activity (aw), oxygen.

Nutrition and Transport Systems: Chemical components. Micronutrients. Energy (phototrophy, chemotrophy, lithotrophy). Organic substances (autotrophs, heterotrophs). Growth factors. Transport systems (primary, secondary, group translocation).

Microbial Metabolism: Energy processes. Fermentation and respiration. Electron transport, redox potential, and bioenergetics. Membrane transporters and generation of Proton Motive Force. Energy cycles. Glycolysis. Fermentations. Aerobic and anaerobic respiration. Krebs cycle. Assimilative and Biosynthetic Metabolism

Bacterial Genetics: Bacterial genome and nucleoid. Chromosome organization. Replication, transcription, and translation of genetic information. DNA replication methods and involved enzymes. Transcription and translation. Mutations. Recombination. Horizontal gene transfer: transformation, transduction, conjugation.

Bacterial Classification: Phylogeny. Classification methods: genotype and phenotype. Definition of species in microbiology. Major bacterial phyla and characteristics, placement of major bacterial microbial groups of interest, particularly Pseudomonadaceae, Enterobacteriaceae, lactic acid bacteria, Bacillus, Clostridia, Staphylococci, Micrococci, Listeria, Bifidobacteria.

Microorganisms and Animal-derived Foods: Spoilage, pathogens, and toxin producers.

Principles of Microbial Transformations and fermentations: Criteria for the selection of starter microorganisms and their selection.
Fermentations and the microbial role in cheese making and fermented milk.
Fermentation of meat: the production process and the role of microorganisms in salami production.

Silage.

Laboratory Exercises: Optical microscopy. Microbial growth curve: enumeration and determination of growth phases of cultures using direct methods (plate counting) and indirect methods (optical density measurement). Microbiological sampling using plate seeding methods, both inclusion and surface spreading. Counting and identification of microbial load in samples for different microbial groups. Techniques for isolating microorganisms on plates; purification of isolates and their characterization: microscopic observation (cell morphology) and catalase test. Fermentation tests.

Readings/Bibliography

Microbiologia Generale ed Agraria (a cura di Claudia Sorlini e Bruno Biavati). CEA Editrice Milano

Microbiologia alimentare applicata (a cura di Luca Cocolin, Marco Gobbetti, Erasmo Neviani) CEA Editrice Milano

Teaching methods

The teaching will be done through classroom lectures with the help of slides for theoretical background and practical training lessons.
Attendance at the laboratory sessions requires all students to complete Modules 1 and 2 of the e-learning safety training and to attend Module 3 on health and safety in study environments. Information on the dates and attendance procedures for Module 3 is available in the dedicated section of the degree programme website.

Assessment methods

Final written test consisting of two parts. Three open-ended questions, each of which is associated with a value of 3 points, and 24 multiple-choice questions, each of which is associated with a maximum of one point. The test lasts 120 minutes and consultation of texts, notes and other media is not permitted. To pass the test, the candidate must achieve at least 18 points. Reaching a score of 31 awards the candidate honours.

To pass the exam, knowledge of the topics covered in the syllabus and the use of correct language and appropriate technical terminology are required. In order to achieve a mark of more than 25, the student must demonstrate critical analysis skills and the ability to connect the topics in a logical-deductive manner.

The professor reserves the right to supplement the written examination with an oral examination, whenever deemed appropriate, in order to verify the achievement of the intended learning outcomes and the student's actual level of preparation.

The use of artificial intelligence (AI) is not permitted during the assessment. Any use of AI constitutes a violation of academic integrity.

Students with learning disorders and\or temporary or permanent disabilities: please, contact the office responsible (https://site.unibo.it/studenti-con-disabilita-e-dsa/en/for-students) as soon as possible so that they can propose acceptable adjustments. The request for adaptation must be submitted in advance (15 days before the exam date) to the lecturer, who will assess the appropriateness of the adjustments, taking into account the teaching objectives.

Teaching tools

Slides

Office hours

See the website of Giulia Tabanelli