Food quality and safety is the main target of investigation in food microbiology. Therefore, reliable paths to detect, quantify, identify, characterize and monitor microorganisms occurring in food are of great interest. The target bacteria can be spoilage, pathogenic or microorganisms involved in fermentations with a technological relevance. In the case of fermented foods, microorganisms play a pivotal role contributing to the improvement of the physiochemical, sensory and safety characteristics of the final products. They not only produce organic acids that lower the pH and limit the growth of pathogenic and spoilage microorganisms, but they also perform metabolic activities contributing to aroma development. The presence of pathogens in food has to be carefully prevented, and appropriate strategies are developed and applied in order to monitor their presence along the food chain. In spoilage-related microorganisms, the metabolic activities from bacteria, yeast and moulds can lead to food deterioration caused by the release of volatile organic metabolites that can determine a sensory decay of the spoiled food. In all the above cases the food can be contaminated and act as substrate for the development of very complex microbial consortia in which many different microorganisms co-exist and interact in the same environment.
Traditionally, the microbial ecology of foods has been studied by using traditional microbiological analysis based on the use of synthetic culture media. However, this approach is not always appropriate to study complex microbial communities because it often fails to properly profile the existing diversity. For this reason, new approaches based on the application of molecular methods have been developed in the last 15 years, bringing new insights in the microbial ecology of foods. The molecular approaches include the use of methods for the identification and characterization of microbial isolates from food (culture-dependent methods), as well as direct application of molecular biology techniques in order to assess the microbial diversity without the need for cultivation (culture-independent methods). In this last case, the microorganisms are detected by targeting nucleic acids extracted directly from the food sample, and problems relating to the lack of growth of some populations, or the need of selective/elective enrichments to recover stressed or injured cells, do not compromise the outcome of the investigation. Studies on development, optimization and application of molecular techniques in the field of food microbiology are of utmost importance to make powerful tools available for the monitoring and improvement of food quality and safety.
Food quality and safety is the main target of investigation in food microbiology. Therefore, reliable paths to detect, quantify, identify, characterize and monitor microorganisms occurring in food are of great interest. The target bacteria can be spoilage, pathogenic or microorganisms involved in fermentations with a technological relevance. In the case of fermented foods, microorganisms play a pivotal role contributing to the improvement of the physiochemical, sensory and safety characteristics of the final products. They not only produce organic acids that lower the pH and limit the growth of pathogenic and spoilage microorganisms, but they also perform metabolic activities contributing to aroma development. The presence of pathogens in food has to be carefully prevented, and appropriate strategies are developed and applied in order to monitor their presence along the food chain. In spoilage-related microorganisms, the metabolic activities from bacteria, yeast and moulds can lead to food deterioration caused by the release of volatile organic metabolites that can determine a sensory decay of the spoiled food. In all the above cases the food can be contaminated and act as substrate for the development of very complex microbial consortia in which many different microorganisms co-exist and interact in the same environment.
Traditionally, the microbial ecology of foods has been studied by using traditional microbiological analysis based on the use of synthetic culture media. However, this approach is not always appropriate to study complex microbial communities because it often fails to properly profile the existing diversity. For this reason, new approaches based on the application of molecular methods have been developed in the last 15 years, bringing new insights in the microbial ecology of foods. The molecular approaches include the use of methods for the identification and characterization of microbial isolates from food (culture-dependent methods), as well as direct application of molecular biology techniques in order to assess the microbial diversity without the need for cultivation (culture-independent methods). In this last case, the microorganisms are detected by targeting nucleic acids extracted directly from the food sample, and problems relating to the lack of growth of some populations, or the need of selective/elective enrichments to recover stressed or injured cells, do not compromise the outcome of the investigation. Studies on development, optimization and application of molecular techniques in the field of food microbiology are of utmost importance to make powerful tools available for the monitoring and improvement of food quality and safety.
