Exploring levan oligosaccharide-producing organisms to protect strawberry fruit

The use of Bio-Control Organisms (BCOs) and natural protective or so called “priming” compounds is gaining momentum, offering opportunities for sustainable and environmentally friendly disease control on various crop species. Strawberry is a highly popular small fruit crop worldwide with a significant economic importance and a large market share in Europe. In Belgium and Estonia strawberry is the most important berry crop. Diseases caused by fungal pathogens on strawberry plants are causing tremendous economic loss. The aim of the project is to incorporate the expertise of research groups at KU Leuven (Prof. W. Van den Ende; Belgium), University of Tartu (Assoc. Prof. T. Visnapuu; Estonia) and University of Stellenbosch (Dr. S. Peters; South Africa) for exploration and initial screening of microbial communities in strawberry fruit that grow better on levan, levan oligosaccharides (LOS) or other types of natural oligosaccharides that are known to exert prebiotic effects and/or boost plant immunity. Focus will be on LOS producing bacteria harboring endo-levanases that are able to protect strawberry from grey mold (Botrytis cinerea). The effect of combinations of selected candidate BCOs and oligosaccharides will be evaluated during the fruit production and postharvest stages. The goal is also to increase our insights in structure-function relationships of the carbohydrate-degrading enzymes that are involved in such processes. These will on the longer term greatly stimulate enzyme design-based applications and the development of superior priming compounds and prebiotics that will be required to reduce the widespread use of agrochemicals and antibiotics through plant and animal disease prevention strategies.