Final Report Summary - BIAMFOOD (Controlling Biogenic Amines in Traditional Food Fermentations in Regional Europe)
Food fermentations are among the traditional industries that have a long standing history worldwide. In spite of great technological advantages, much of the industry is still based on traditional, experienced-based techniques that are strongly rooted in specific geographic regions. In food fermentations, consortia of microorganisms are essential to the process, and determine the characteristics of the end products. They also are responsible for the production of biogenic amines (BA) that may cause serious human health problems following ingestion of fermented foods containing high concentrations of these compounds. This project focuses on the microorganisms in the food chain that produce biogenic amines with the main goal to improve the quality of traditional fermented food products by reducing/eliminating their biogenic amine content. Control of biogenic amines in the food products will significantly reduce the health risk for the consumer and, thereby, increase the competitiveness of the local industries. The challenge for the food industry is to produce food and beverages in which the levels of BA are minimized. The project focuses on three different fermentation processes in four different region of Europe. The project has both an analytical component aiming at identifying BA producers in the food chain and the conditions that result in BA production, as well as a controlling component aiming at a significant reduction or even elimination of BA in the food products. The whole food chain is considered. At the beginning of the food chain, the potential of microorganisms to form BA is analyzed; during the fermentation process the physiological conditions that result in BA formation are controlled and at the end of the chain the survival of microorganisms producing BA in the digestive tract is analyzed and their effect on the consumer considered.
The distribution of BA-producing bacteria over 1200 bacterial strains for which the genome sequence was available in the public domain and over ~1500 strains obtained from cider, cheese and wine fermentations was determined producing a database of information for studies of biogenic amines in food fermentations. A unique lysine decarboxylase was identified by whole genome sequencing of Lactobacillus 30a and a new biosynthetic ornithine decarboxylation pathway was characterized. PCR, HPLC and TLC based tools were developed and optimized in order to detect lactic acid bacteria (LAB) harboring genes involved in the production of the biogenic amines in the food chain. The tools and techniques were used to detect BA-producers and BA in food and in different stages of production of wine, cheese and cider. The physiological role of BA producing pathways was studied in different biological systems demonstrating the relation between acid resistance and turnover through the pathways. Factors affecting the expression of the pathways were determined and a hierarchical catabolite repression regulation of citrate/malate and BA prodicing pathways was demonstrated. BA-degrading isolates from cheese and wine were able to significantly reduce the BA content of the products. Exposure of humanan monocyte-derived dendritic cells and macrophages to BA lead to diminished immunogenic or inflammatory responses. Finally, problems encountered with the expression of transporters of O. oeni are not related to the protein family or the host per se, but rather protein specific.
The distribution of BA-producing bacteria over 1200 bacterial strains for which the genome sequence was available in the public domain and over ~1500 strains obtained from cider, cheese and wine fermentations was determined producing a database of information for studies of biogenic amines in food fermentations. A unique lysine decarboxylase was identified by whole genome sequencing of Lactobacillus 30a and a new biosynthetic ornithine decarboxylation pathway was characterized. PCR, HPLC and TLC based tools were developed and optimized in order to detect lactic acid bacteria (LAB) harboring genes involved in the production of the biogenic amines in the food chain. The tools and techniques were used to detect BA-producers and BA in food and in different stages of production of wine, cheese and cider. The physiological role of BA producing pathways was studied in different biological systems demonstrating the relation between acid resistance and turnover through the pathways. Factors affecting the expression of the pathways were determined and a hierarchical catabolite repression regulation of citrate/malate and BA prodicing pathways was demonstrated. BA-degrading isolates from cheese and wine were able to significantly reduce the BA content of the products. Exposure of humanan monocyte-derived dendritic cells and macrophages to BA lead to diminished immunogenic or inflammatory responses. Finally, problems encountered with the expression of transporters of O. oeni are not related to the protein family or the host per se, but rather protein specific.
