ProBioControl: Metabolic profiling of antifungal active bacteria, for potential use as biocontrol agents

Conventional agriculture in Germany is responsible for almost all of the pollution of the environment with chemical pesticides. At around nine kg/ha/year, the use of these PPPs leads to a loss of biodiversity, the destruction of habitats and the manifestation of pesticides in food chains. In addition, agriculture causes 7.5% of German greenhouse gas emissions and is therefore a driver of climate change.

The rate of biodiversity loss and global warming have already exceeded a critical limit. This leads to extreme climatic events such as longer and more frequent dry periods and heavy rainfall, weakening German ecosystems. In this tense situation, plant pests are on the rise.

In order to counteract these developments, a transformation and reorientation of agricultural systems towards bioeconomically compatible, sustainable food production is essential. Efforts to promote organic farming are an essential part of this. However, this form of cultivation in particular lacks pesticides to combat plant pathogens. This makes the entire sector vulnerable. 

Fungal diseases are a significant factor in high yield losses in organic farming. A number of organically applicable biocontrol agents are available on the market, but in many cases there is a lack of knowledge about their exact mode of action.

The aim of the project is to identify and characterise microbial strains that can be used as antifungal biocontrol agents. The basis for this is the Fraunhofer IME's strain collection of 120,000 microorganisms.

Two important fungal diseases in Germany are to be addressed in this context: Septoria leaf blight as the most widespread disease in wheat worldwide and black spot disease in potatoes, which benefits particularly from climate change.

By analyzing the metabolic and genomic properties of the new strains, we will gain previously missing insights into the metabolic functions that contribute to the effectiveness of biocontrol agents. In addition, tests are included to identify solutions with a favourable ecological and toxicological profile. 

The fungicidal properties of soil-dwelling bacteria as natural components of soil ecosystems are being researched. State-of-the-art metabolomics and genomics technologies are being used to comprehensively determine the metabolic capabilities of the bacteria being investigated. This will be realised in a three-phase project:

• 1. Identification and characterisation of bacteria that show a promising natural product profile. Guided by antifungal bioactivity data, the metabolic profile of the strains will be recorded and evaluated. This allows the production of plant-promoting substances as well as harmful metabolites to be recognised.

• 2. New natural products with antifungal activity are isolated and their structure elucidated. The identified strains and natural products are profiled. The antifungal potency is determined and eco-, cell- and phytotoxicological tests on environmental compatibility are carried out.

• 3. The most promising bacteria and natural products are tested in plant infection experiments. This will allow the effectiveness of the bio-based products in disease control to be determined.

The project will provide knowledge on the metabolic capabilities of bacteria and point the way towards ecologically sustainable biocontrol agents.