General Microbiology

A.Y. 2024/2025
9
Max ECTS
80
Overall hours
SSD
BIO/19
Language
Italian
Learning objectives
The aim of the course is to illustrate the structure and the function of the prokaryotic cell and the mechanisms underlying genetic variability and adaptation to environmental stimuli. The laboratory module will introduce the student to basic microbiology techniques and will assess basic notions of microbial physiology.
Expected learning outcomes
After following this course, the student will acquire a good knowledge of:
- the structure and physiology of prokaryotic cells
- the mechanisms of transfer and regulation of bacterial genes
- the conditions affecting growth of prokaryotes and the tools for monitoring growth
- main antibiotics and their mode of action
- general features and replication strategies of viruses and bacteriophages.

Moreover, thanks to the attendance at the laboratory module, the student will be able to:
- set-up pure bacterial cultures and monitor their growth
- identify, describe and distinguish Gram positive and Gram negative bacteria
- identify and describe a bacterial spore.
Single course

This course can be attended as a single course.

Course syllabus and organization

A - L

Responsible
Lesson period
Second semester
Course syllabus
Historical context of Microbiology birth as a science.

Structure and function of microbial cells.
Microbial associations: the biofilm.
Comparison among cells of Eukaryotes, Bacteria and Archaea.
Morphological features of main microbial groups.
Capsule. Cell wall.
Cytoplasmic membrane. Pili and flagella.
The nucleoid. Structure and organization of the chromosome.
Cytoplasm. Cytoplasmic inclusions.
Endospores.

Microbial growth and its control (see also the laboratory module)
Media and growth conditions. Pure cultures. Growth inhibition. Antibiotics: structure and mode of action, minimal inhibiting concentration, mechanisms of resistance.

Metabolism: metabolic, physiological and ecological characteristics of the principal microbial groups.
Central metabolism and biosynthetic reactions.
Energy metabolism: Fermentation, aerobic and anaerobic respiration, chemiolithotropy, phototrophy.
Assimilation of C: autotrophy and heterotrophy. Assimilation of N. Nitrogen fixation. Assimilation of S and P. Regulation of biosynthetic pathways at enzyme level. Allosteric enzymes.

Regulation of gene expression
Strategies and levels of regulation.
Positive and negative regulation of transcription initiation.
Regulation of transcription termination. Attenuation (trp operon).
Regulatory networks. Catabolite repression.
Ribosomes and polysomes. Stringent response. Alarmones.

Genome structure and DNA replication.
Binary division and other division strategies.
Examples of differentiation in bacteria.

Microbial Genetics
Mutations. Selection and screening of mutants.
Mechanisms of genetic transfer. Transformation. Plasmids: General properties. Replication and partitioning. Conjugation.
Bacterial viruses (Bacteriophages): Lytic cycle. Lysogenic cycle. Control of lysogeny. Generalized and specialized transduction. Evolutionary implications. Phage therapy. Anti-phage systems.
Animal viruses: structure, main infection and propagation mechanisms..
Transposable elements: structure and properties. Mechanisms of transpositions.

Interaction between prokaryotes and other organisms. Microbiota and virome.


LABORATORY MODULE
The laboratory is an integral and mandatory part of the course.

The methods of microbiology
Methods of sterilization. Pure cultures.
Growth media. Influence of nutritional requirements, temperature, pH, oxygen, light.
Growth, enrichment and selection of microorganisms.
Microscopy. Staining techniques
Prerequisites for admission
The student should have basic knowledge of Organic chemistry, Biological chemistry, Genetics and Molecular biology.
Teaching methods
Interactive lectures supported by projected material. The student will be fully involved in the discussion. Attendance at the lectures is highly recommended. The laboratory consists of 3 afternoons with mandatory attendance to performing experiments supporting the theoretical notions presented during the lectures and the completion of a short report on the activities carried out.
Teaching Resources
Dehò, G., Galli, E. Biologia dei microrganismi. Terza edizione, Casa Editrice Ambrosiana. A textbook in English will be recommended upon student's request.
Copies of the slides shown during the lectures will be made available through the course website on the MyARIEL platform of the University of Milan
Assessment methods and Criteria
The evaluation of the student's knowledge of the topics discussed during the lessons is based on a written examination consisting of 3 parts: i) 30 multiple choice questions (18 points max); ii) design and analysis of a growth curve (4 points max); iii) recognition/brief comment about images schematically representing molecules/structures/pathways presented during the course (8 points ); 1 question (1 point) about the lab, To pass the exam the students are required to answer correctly to 20 multiple choice questions and to reach an overall evaluation ≥ 18/30. Honors will be given to those who score 31/30. Students have 30 minutes to answer to the multiple choice questions and the overall duration of the test is 90 minutes. For those who, according to the provisions in force, have the right to take the exam remotely, the exam will be entirely oral.
BIO/19 - MICROBIOLOGY - University credits: 9
Practicals: 16 hours
Lessons: 64 hours
Shifts:
Professor: Briani Federica
Turno 1
Professor: Briani Federica
Turno 2
Professor: Landini Paolo

M - Z

Responsible
Lesson period
Second semester
Course syllabus
[Program with reference to descriptor 1 and 2]:
Structure and function of microbial cells
Comparison among cells of Eukaryotes, Bacteria, and Archaea.
Morphological features of main microbial groups.
Capsule. Cell wall.
Cytoplasmic membrane. Pili and flagella.
The nucleoid. Structure and organization of the chromosome.
Cytoplasm. Ribosomes and polysomes. Cytoplasmic inclusions.
Endospores.

Microbial growth and its control (see also the laboratory module)
Media and growth conditions. Pure cultures. Growth inhibition. Antibiotics: structure and mode of action, minimal inhibiting concentration, mechanisms of resistance.

Metabolism: metabolic, physiological, and ecological characteristics of the principal microbial groups.
Central metabolism and biosynthetic reactions.
Energy metabolism: Fermentation, aerobic and anaerobic respiration, chemiolithotropy, phototrophy.
Assimilation of C: autotrophy and heterotrophy. Assimilation of N. Nitrogen fixation. Assimilation of S and P. Regulation of biosynthetic pathways at enzyme level. Allosteric enzymes.

Microbial Genetics
Mutations. Selection and screening of mutants.
Mechanisms of genetic transfer. Transformation. Plasmids: General properties. Replication and partitioning. Conjugation.
Bacterial viruses (Bacteriophages): Lytic cycle. Lysogenic cycle. Control of lysogeny. Generalized and specialized transduction. Recombination. Evolutionary implications
Animal viruses: structure, main infection, and propagation mechanisms.
Transposable elements: structure and properties. Mechanisms of transpositions.

Regulation of gene expression
Strategies and levels of regulation.
Positive and negative regulation of transcription initiation.
Regulation of transcription termination. Attenuation (trp operon).
Genome structure (DNA topology and genome rearrangements).
Regulatory networks. Catabolite repression. Stringent response. Alarmones.

Interactions of prokaryotes with other organisms
Interactions between bacteria: the cooperative processes. Quorum Sensing. The microbial associations: biofilms.

An outline of microorganism-eukaryotic host interactions: interactions bacteria-animal organisms; beneficial and harmful interactions of bacteria with plant organisms

LABORATORY MODULE
The laboratory is an integral and mandatory part of the course.

The methods of microbiology
Methods of sterilization. Pure cultures.
Growth media. Influence of nutritional requirements, temperature, pH, oxygen, light.
Growth, enrichment, and selection of microorganisms.
β-galactosidase activity assay
Microscopy. Staining techniques
Prerequisites for admission
The student should have basic knowledge of Organic chemistry, Biological chemistry, Genetics, and Molecular biology.
Teaching methods
Teaching mode: interactive lectures supported by projected material. The student will be fully involved in the discussion. The laboratory program includes experiments supporting the theoretical notions presented during the lectures.
Attendance at the lectures is highly recommended. Attendance at the laboratory is mandatory.
Teaching Resources
Dehò, G., Galli, E. Biologia dei microrganismi. Terza edizione, Casa Editrice Ambrosiana.
Presentations shown in class will be available on the Professor's myARIEL site.
Assessment methods and Criteria
The evaluation of the student's performance is based on a written examination consisting of 30 multiple-choice and 3-4 open-ended questions that will account for 1/3 and 2/3, respectively, of the overall evaluation of the examination. To pass the exam the students are required to answer correctly 20 multiple choice questions and to reach an overall evaluation ≥18/30.
BIO/19 - MICROBIOLOGY - University credits: 9
Practicals: 16 hours
Lessons: 64 hours
Shifts:
Professor: Bertoni Giovanni
Turno 1
Professor: Bertoni Giovanni
Turno 2
Professor: Paroni Moira
Educational website(s)
Professor(s)
Reception:
Every day from 9 am to 6 pm, by appointment
on-line via Teams platform
Reception:
wednesday 15:30-16:30 on appointment required by e-mail
DBS, via Celoria 26, 4th floor, tower C
Reception:
On appointment by e-mail
Via Celoria 26, Scientific buildings, 4th floor, Tower "B"
Reception:
10am-12pm (by email appointment)
Department of Biosciences (Scientific Buildings) - 1st floor Tower B