Mechanism, distribution and significance of bacterial mycoparasitism in soil
12 / 2003 - 12 / 2008
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
Many soil bacteria produce chitinases and other lytic enzymes that have been shown to lyse living fungal hyphae. Therefore such bacteria may be able to use living fungi as growth substrate i.e. analogous to so-called mycoparasitism that is known for certain soil fungi. However, so far no information is available on the occurrence of bacterial mycoparasitism. We have demonstrated that a newly defined genus of bacteria, Collimonas, can grow on living hyphae in soil microcosms. The Collimonas bacteria are dominant among the chitinolytic bacteria in acidic, fungal rich soils indicating the potential importance of bacterial mycoparasitism. The proposed project seeks to uncover the mechanisms, in situ occurrence and consequences for fungi of mycoparasitic growth of Collimonas. Identification of phenotypic characteristics and/or genes that are essential for mycoparasitism of Collimonas will be used to develop a protocol to screen soil bacteria for mycoparasitic potential. The major goals of the proposed project are to determine: 1. the mechanism and regulation of bacterial mycoparasitism, 2. the in situ occurrence of bacterial mycoparasitism, 3. the possible consequences of bacterial mycoparasitism for the turnover of fungal biomass and the shaping of fungal communities and 4. the mycoparasitic growth potential among soil bacteria.