The importance of mycophagy for the ecology and evolution of the bacterial genus Collimonas and for other soil bacteria
10 / 2009 - onbekend
The genus Collimonas consists of soil bacteria that can grow at the expense of living fungal hyphae in both model and natural soils. Mycophagy can be regarded as an extension of the possibilities of bacteria to obtain nutrients. It has been hardly addressed so far but could be very important for the ecology and evolution of soil bacteria since soils are limited in the availability of nutrients for microbial growth and since both bacteria and fungi are abundant in many soils. The current proposal will focus on both ecological and evolutionary aspects of mycophagy in collimonads. Major questions to be addressed are i) to what extent do collimonads rely on mycophagy for growth and survival? ii) how has mycophagy evolved in the genus Collimonas and iii) is mycophagy restricted to collimonads ? The research questions will be addressed using the collection of Collimonas strains in our department. These bacteria will be confronted with plant exudates, fungi and other bacteria in model soil systems. Responses of collimonads to specific (a)biotic conditions will be examined using the tools that we have developed or adapted to study them e.g. gene expression microarrays , Collimonas-specific primers for qPCR analysis and RNA-stable isotope probing . Multilocus Sequence Analysis (MLSA) will be used to test whether distinct phenotypes (e.g. specificity in fungal attack) are restricted to specific lineages or are wide-spread within the genus. Another part of the project will address the distribution of mycophagy among other soil bacteria. The obtained results will form a solid basis to value and exploit bacterial mycophagy and to assess the impact on soil ecosystem functioning.