Microbiology and food microbiology

A.Y. 2019/2020
Overall hours
Learning objectives
The course aims to provide students with the knowledge related to the use and role of microorganisms in the food context. The course will be structured as a didactic path that will guide the student to acquire the basic scientific knowledge to understand microbial metabolism and to critically deal with the microbiological problems typical of the food sector as well as the management of industrial fermentations aimed at the production of microbial biomass or their metabolites.
Expected learning outcomes
At the end of the course the students will be able to use in the professional field the concepts learned about the biology of microorganisms and their use in the food sector. Specifically, at the end of the educational path the student will be able to know and to know how quantify the presence of main pathogens, alterative agents and quality indicators in food products. The student will also be competent in applying the acquired knowledge in order to prevent, control or use the presence of microorganisms in the food production and distribution process. The student will also acquire skills related to the use of the main industrial fermentations aimed at the production of microbial biomass or their metabolites.
Course syllabus and organization

Single session

Lesson period
Course syllabus
Short course description
Description of eukaryotic prokaryotic microorganisms and viruses; morphological characteristics, energy metabolism and relationships with oxygen, nutritional and cultural needs, habitats, chemical-structural, immunological and genetic-molecular characteristics. Microbial growth, metabolism, mutations, horizontal gene exchange mechanisms. Definition of microbial species. Taxonomy and metabolism of the main microbial groups of food interest.
Main physiological characteristics of microorganisms associated with food. Description of the microorganisms involved in food poisoning, infections and cough infections. Microbiology of food and food processes. Principles of industrial microbiology: from the formulation of a culture medium to the parameters involved in the management of a microbiological process on an applied scale.

Detailed course description
Definition of microorganism. Structure of the prokaryotic and the eukaryotic cell. Anatomy of the bacterial cell: structure, chemical composition and functions of the capsule, cell wall, cell membrane. Structure of teicoic and lipoteicoic acids. Membrane transport systems. The chemical composition of the cell and the nutritional factors. Microbial growth: growth in bacteria and in the yeast Saccharomyces cerevisiae. Description of the growth curve. Description of direct and indirect methods for counting microorganisms. Energy metabolism: aerobic and anaerobic respiration, fermentation. Anabolism and the definition of auxotrophy and prototrophy. Anaplerotic reactions. Principles of microbial genetics: structure and composition of DNA and RNA. DNA replication. The genetic code. The transcriptional organization of genes. RNA synthesis, protein synthesis. Gene regulation: examples of positive and negative regulation. Mutations and mechanisms of gene repair. Plasmids. Viruses. The mechanisms of resistance to bacteriophages. The mechanisms of horizontal gene exchange: transduction, conjugation and transformation. Principles of bacterial taxonomy: the definition of species, the polyphasic approach in the identification of species. Ribosomal genes and their relevance in the taxonomy of living beings. Polymerase chain reaction: principles and applications.
Presence and development of microorganisms in food. Sources of contamination during the production and distribution process. Factors influencing microbial development (temperature, radiation, aw, pH and organic acids, redox potential, packaging in a modified atmosphere, preservatives and natural antimicrobial substances). Description of the main microbial groups of food interest and their metabolism: lactic acid bacteria, acetic bacteria, sporeforming bacteria, enterobacteria, pseudomonadaceae, micrococcaceae, bifidobacteria, and eumycetes). Activities of microorganisms on food: pro-technological microorganisms, microorganisms as quality indexes. Foodborne illnesses. Foodborne infections (Salmonella spp., Shigella spp., V. cholerae, L. monocytogenes etc.), toxinfections (B. cereus, C. Perfringens), bacterial intoxications (S. aureus, C. Botulinum), fungal (mycotoxins), intoxication from algal populations, biogenic amines and viruses. Microbiological aspects of the most important food products (milk and derivatives, cereals and derivatives, meat and derivatives, fruit and vegetables, water, soft drinks, low aw products). Principles of the HACCP system.
Principles of industrial microbiology. Formulation of a culture medium: raw ingredients (carbon and nitrogen sources, growth factors) and complex media. The fermenter and its main elements: process parameters and management of temperature, pH, foam, oxygen and stirring systems. The air line and water management in a fermentation plant. Production of baker's yeast, beer, vinegar, mesophilic and thermophilic fermented milks, production of mushrooms (higher fungi).
Prerequisites for admission
basic knowledge of chemistry, organic chemistry and biochemistry
Teaching methods
frontal lessons
Teaching Resources
Lecture slides and reference textbooks are available on Ariel. The teachers are available for further clarification by appointment.
Assessment methods and Criteria
The exam is organized in a written test that includes open and timed questions, with a maximum value of 30/30 and honors.
Any additional information on the evaluation methods will be illustrated during the course. The exam method described is considered effective to achieve an assessment of the skills acquired by the student in the context of general and food microbiology, which examines the topics covered in class in their entirety and complexity.
During the Covid-19 disease emergency period, the exam will remain written but it will be conducted remotely according to the indications that will be provided by the teachers.
AGR/16 - AGRICULTURAL MICROBIOLOGY - University credits: 12
Lessons: 96 hours
appointment by phone
via Mangiagalli, 25 (floor IV room 4021)
By e-mail appointment
Office, via Mangiagalli 25, third floor
to be defined via email