Grant: Canada Research Chairs

Dr. Gänzle’s has maintained international visibility in both areas of food fermentations and food safety. The relatively broad area of research in the group generates synergies from using fundamental ecological concepts to understand the assembly of microbial communities in biofilms or in food fermentations, or the persistence of Listeria and spoilage microbes in food processing plants. The proposed research program aims to conceptually advance three areas of investigation: 1) The societal context of bacterial communities 2) The use of bacilli and Enterobacteriaceae as beneficial food fermenting microbes. 3) The conversion of phytochemicals to bioactive or antimicrobial products The social context of food-associated bacteria will be studied with three model systems: - A complex daqu model which will consist of 9 fungal and bacterial strains. Daqu is a spontaneously fermented saccharification culture that is populated by fungi and bacilli, which produce hydrolytic enzymes, as well as plant-associated Enterobacteriaceae and lactic acid bacteria. - Formation of multi-species biofilms in food processing plants. Current work has established a collection of about 2000 isolates from more than 100 sampling sites in a meat processing plant that will be re-constituted to study multi-species biofilms in complex bacterial communities. - Flavor formation by yeasts and lactobacilli. Flavor formation by yeasts is strongly impacted by the presence of lactic acid bacteria but this interaction has not been systematically explored. . In the European / North American tradition of food fermentations, bacilli are not recruited as beneficial microbes in food fermentations but are considered mainly as spoilage or pathogenic microbes. The use of bacilli likely greatly facilitates the development of novel, minimally processed and fermented plant foods to improve the security and sustainability of global food systems. During fermentation, phytochemicals including polyphenols are modified by the metabolic activity of fermentation microbes. The substrate specificity of the multiple enzymes - 3 to 20 per genome - that are predicted to be active on glycosylated phytochemicals, however, remains poorly elucidated. Each of these objectives will inform and stimulate specific projects in the areas of food fermentation and food safety to achieve improved control of microbial communities in food, and an improved food quality and food safety.