Sustainable agricultural crop production, global nutrition and the use of natural, renewable resources for production processes are central topics of the envisaged bioeconomy. Around the world losses of crop harvest due to parasitic nematodes are estimated to account to more than a billion dollar. Surface active molecules (surfactants) that are produced by microbes are called biosurfactants. There are reports about biosurfactants with antimicrobial and plant growth promoting properties.
The objective of NovoSurf was to identify unknown microbial surfactants and test their effect on nematodes and plants. Identification of such a compound may in future be exploited for the development of alternative strategies to increase plant yield and for the control of plant parasitic nematodes which are important pathogens in agricultural crop production.
Within this one year project, we identified bacterial soil isolates that likely produce unknown biosurfactants. As working with bacterial isolates is restricted to the cultivable organisms only, a metagenomic approach utilizing the microbial gene pool present in our soil sample is in progress. Culture supernatants of selected bacterial isolates caused increased mortality of the model nematode Caenorhabditis elegans which is already a good indicator that they may also be active against plant parasitic nematodes like Heterodera schachtii. For estimating the efficacy of a biosurfactant on nematodes, purified mono-rhamnolipids, which are naturally produced by Pseudomonas and other bacteria, were analyzed in this respect. A rhamnolipid concentration of 8.3 ppm was sufficient to kill about 96 % of C. elegans within 48 hours. The same concentration of rhamnolipids in a plant growth medium reduced the number of infections by H. schachtii and the number of offspring per plant by about 90 %. Interestingly, the rhamnolipids seem to induce plant defense responses that are effective against H. schachtii as plants triggered with these molecules at a concentration of 8.3 ppm revealed an about 30 % lower infection rate and the offspring per plant was about halved. With these results NovoSurf offers two research routes to combat nematodes: (1) biosurfactants - nematode interaction and (2) biosurfactants, plant and then nematode interaction.
Participating Core Groups
Prof. Florian Grundler, Dr. Sylvia Schleker, Institut für Nutzpflanzenwissenschaften und Ressourcenschutz (INRES), Molecular Phytomedicine, University Bonn
Prof. Lars Blank, Till Tiso, Institute of Applied Microbiology, RWTH Aachen University
Dr. Sylvia Schleker, INRES, Molecular Phytomedicine, University Bonn
phone: +49 (0)228 73-3900
01.04.2015 – 31.03.2016
NovoSurf is part of the NRW-Strategieprojekt BioSC and thus funded by the Ministry of Innovation, Science and Research of the German State of North Rhine-Westphalia.