Foto del docente

Patrizia Brigidi

Full Professor

Department of Medical and Surgical Sciences

Academic discipline: CHIM/11 Chemistry and Biotechnology of Fermentation


Keywords: Microbiome Metagenomics and culturomics Microbiome modulation

Scientific Research Activity


The work of Prof. Patrizia Brigidi is documented by several publications in international journals. The principal topics covered in her work have been:

genetic improvement of industrial microorganisms;

molecular identification of probiotic strains;

 study of the molecular mechanisms responsible for the health promoting activities of probiotics;

characterization of human complex ecosystems (gut microbiota, vaginal microflora);

fermentation processes for biomass production of Bacillus stearothermophilus and Lactobacillus strains;

analysis of antimicrobial activity of traditional compounds and new synthesized molecules.

1.Characterization of the human intestinal microbiota by molecular techniques: set up of a microarray platform. The recent development of culture-independent molecular approacches allowed to characterize complex ecosystems, such as the human gut microbiota. In particolar, the molecular analysis allows to evaluate qualitative and quantitative modifications of the predominant intestinal microbial groups related to different physio-pathological conditions of the subjects analyzed and environmental stimuli, such as the intake of antibiotics and functional foods. DNA microchips (Community Genome Arrays, CGAs) represent a potent and robust genomic technology, commonly used to study biological systems and processes. However, up to now, this technology has not been widely used for the characterization of microbial communities. In this perspective, new chips, based on the employment of microbial ribosomal DNA probes specific for the predominant intestinal microbial groups, will be developed. 2.Genomic and proteomic analysis of health promoting metabolic activities of probiotics. The characterization of an increasing number  of genomes of bacterial probiotics allows to identify putative genes which codify for metabolic activities benificial for the host. In Bifidobacterium and Lactobacillus strains we have identified and characterized the oxc gene, which codifies for oxalyl-decarboxilase, key enzyme for the decarboxilation of oxalate, a toxic compound assumed with the diet. The proteomic analysis allows to verify the expression of putative genes envolved in probiotic activities and study the bacterial metabolic responses in different environmental conditions (stress, antibiotics). The proteomic approach has been performed to identify bacterial proteins involved in the bacterial adhesion to intestinal epithelium. 3.Study of the mecchanisms of adhesion of Bifidobacterium cells to human enterocytes. Despite the wide employment of Bifidobacterium strains in probiotic dietary and pharmaceutical preparations, the molecular mechanisms of the interaction between probiotics and host, are still unknown. On the the other hand, several are the published studies about the interaction between enteropathogens and host. By considering that enteropathogens and probiotics colonize the same ecological niche, we hypothesed that they use the same mechanisms for adhering to the intestinal epithelium. In this perspective, we will study the capability of cell wall proteins of Bifidobacterium to bind plaminogen, fibronectin and laminin, which are proteins involved in the cross-talk between enteropathogens and human enterocytes. Different methodologies will be applied in this study, including bidimensional electrophoresis, overlay assay using monoclonal antibodies specific for plasminogen, fibronectin and laminin, immunoelectronmicroscopy, and MALDI-TOF. 4. Analysis of the intestinal metabolic profiles related to the intake of functional foods. The metabolic activities of the gut microbiota strongly impact on the health of the host. Therefore, the metabotyping analysis of fecal samples will be performed, before and after assumption of probiotics and prebiotics, by GC-MS-SPME analysis, with particular attention to the detection of metabolites markers of saccharolytic o proteolytic activities, such as short chain fatty acids, cresols and indols. Furthermore, microbial metabolites potentially involved in gastroenteric pathologies (i.e. ethanol) will be studied.