Funded under the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.3, Theme 10.
Funded under the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.3, Theme 10.
Anti-pseudomonas food cultures development: identification of new stra...
Coordinator
Innovative mitigation measures to reduce the risks through the application of bacterial pathogens challenges in food models. Tailored fermentation processes, based on QPS microorganisms (i.e., biocontrol agents, lactic acid bacteria, non-conventional yeasts, symbiotic culture of microorganisms) and hydrolysed food matrices, will be set-up and integrated in traditional food production protocols to increase food safety. Selected natural antimicrobials (e.g., essential oils) and hydrolysed raw matrices will be used to inactivate pathogens at food processing, storage, and retail levels.
Protective bacterial and phage cultures
The genus Pseudomonas contains more than 100 species: some of those are pathogens for humans, e.g., Pseudomonas aeruginosa causing lung infections, especially in debilitated people, while others (e.g., Pseudomonas fluorescens or Pseudomonas putida) are considered foods contaminants that cause undesired alterations such as discoloration, bitter taste, unpleasant smell or sticky surface. Pseudomonas spp. are environmental microorganisms, with an optimal growth temperature at around 25-30°C, but exhibiting also psychrotrophic characters. These microorganisms are generally resistant to salt (till 2%) and shown minimal nutrient requirements. They are often present in fresh cheeses (e.g., mozzarella), meat or fish products. In addition, brines or wastewaters used in industrial processes result often contaminated by Pseudomonas spp..
The application of food cultures with protective effect against Pseudomonas spp. would reduce the contamination levels, thus preventing economic losses and contributing to the food waste reduction.
The experimental plan would include the following steps:
1) Creation of a “Pseudomonas spp. cocktail” collecting strains isolated from contaminated foods and environmental samples, with the aim to set a specific target for the challenge tests.
2) Screening lactic acid bacteria or other QPS (Qualified Presumption of Safety) microorganisms to identify those able to inhibit Pseudomonas spp.
3) Identification of the mechanisms responsible for the specific Pseudomonas spp. inhibition (e.g., Volatile Organic Compounds analysis, determination of the organic acids produced, MALDI-TOF trials to identify antimicrobial peptides).
4) Test the candidate strains using different laboratory model systems (dairy, vegetable, fish and/or meat), and evaluation of the inhibitory activity.
5) Verify the two most promising strains in final application, e.g., perform validation trials in mozzarella.
Definition of one food culture specifically targeting Pseudomonas spp., resulted effective also in application tests and deep knowledge of the specific mode/s of action.
