At the MUT, that currently preserves about 5300 fungal strains ascribable to more than 1100 species, coming from different environment and ecologic niches. They have been identified using a polyphasic approach integrating the most modern morpho-physiological, chemical and molecular techniques.
Many of the strains have been screened and characterized for physiological features i.e. specific secondary metabolites production, plant growth promoting features, pollutant degraders, etc.
All the information obtained is entered in a dedicated database in continuous upgrading.
In the last years the MUT deeply investigated the mycobiota associated to different seagrasses (Posidonia oceanica) and algae (Asparagopsia taxiformis, Flabelia petiolata and Padina pavonica) in the Mediterranean Sea. Hundreds of fungi have been isolated and characterized for the production of extremozymes (laccases, tannases, etc.) active in presence of high salt concentrations. Many fungi have been screened for the presence of two types of polyketide synthases genes (PKS), whose presence is considered predictive of the capability to produce useful pharmaceutical metabolites. Antimicrobial tests were also carried out to select strains useful for the production of secondary metabolites with antibacterial, antifungal and antialgal activities.
Eventually, a study of the mycobiota associated to polluted water and sediments after an oil spill nearby Gela Italy, June 2013) is on-going.
Protein engineering and enzyme biotechnology
Pollution of watercourses represents a global concern, making necessary the appropriate treatment of industrial and municipal wastewaters. In addition to traditional contaminants (i.e. dyes, amines, phenols, heavy metals, surfactants, etc.), new harmful micropollutants have been recently discovered, as endocrine disrupting chemicals pharmaceutical and personal care products. Conventional processes are inefficient towards these compounds, which, hence, progressively accumulate in watercourses. The MUT is investigating an alternative approach based on fungi and their complex enzymatic pattern, being environmental and technical sustainable.
Several fungi have been already characterized for their enzymatic pattern and a hyper producer of laccases have been selected. For this strain, belonging to the species Trametes pubescens, the laccases production has been optimized till values of about 300.000 U/l.
Renewable resources and green biochemistry
Traditional chemical processes for fine and bulk chemicals production present many drawbacks making them poorly environmental and economically sustainable. On the other hand, biotransformation may be a promising alternative for the production of high-value molecules due to the mild reaction conditions, the low environmental impact and high chemo and stereoselectivity. Among fungal enzymes, laccases and enoate reductases are here investigated as biocatalysts, able to act towards precursors of flavours, polymers, antioxidants, anticoagulants and pharmaceuticals.
Use of lactic-acid bacteria to inhibit growth of fungal spoilage bakery products Fungal spoilage of bakery products causes conspicuous direct losses and it is considered a threat to consumers’ health, due to the fungus’ ability to produce very hazardous mycotoxins. In the bakery industry, chemical preservatives (i.e. calcium propionate) are commonly used, however, during the last few years, to meet the consumer’s demands, producers choose to rely on natural methods of biopreservation. Lactic-acid bacteria (LAB), with a long history of use as biopreservation agents, show good perspective of application also in the bakery industry. Actually they represent, together with yeasts, the dominant microbial component in sourdough, the leavening agent used in the traditional bread making process. During fermentation process, LAB produce antimicrobial metabolites, such as organic acids and small proteinaceous compounds externally secreted, known as bacteriocins.
In collaboration with the Department of Agricultural Forest and Food Sciences, University of Turin, the MUT is screening many bacterial strains for the antifungal activity, trying to understand the mechanisms involved.