In the last years my research has been oriented towards understanding inter-specific bacterial competitive interactions and the role of these interactions for soil functioning.
In the former VENI project entitled “Suppression of plantpathogenic fungi as a result of inter-specific bacterial interactions” we showed that the interaction of taxonomically non-related bacterial strains, isolated from the same soil had strong effects on fungal suppression. Using several complementary methods we discovered that different strains had strong effects on each other’s behaviour and gene expression patterns when grown together under carbon-limited conditions. More detailed analysis indicated that bacteria are able to distinguish among different competitors and fine-tune its competitive strategies.
(Garbeva et al., 2011a_pdf) (Garbeva et al., 2011b_pdf2)
My research on bacterial inter-specific interactions in now extended with (i) understanding the role of bacterial volatiles in inter-specific communication and competition (ii) discovering novel antimicrobials produced as a result of competitive inter-specific bacterial interactions and (iii) understanding the best bacterial competitive strategies in the rhizosphere
- Meervoud Project (2010- present): Bacterial interactions in soil: the role of volatiles as infochemicals and competitive tools
It is well known that soil microorganisms can produce a wide variety of chemical compounds, including volatiles. Volatiles can distribute well in the soil matrix as they are able to diffuse through both the water- and gas-filled pores in soil. Hence, volatiles are excellent candidates for the discovery of new modes of microbial competitive interactions and communication, and could be important in interactions between relatively distantly distributed soil microorganisms.
In this project we test the hypothesis that bacterial volatiles are playing significant roles in bacterial inter-specific competitive interactions in soil. Volatiles could act as infochemicals providing information on the competing strains and as antimicrobial compounds directly suppressing competitors. Using soil model-systems and selected soil bacterial strains we study the impact of bacterial volatiles on phenotypic changes, competitive ability and gene expression. Garbeva et al., 2014a; Garbeva et al., 2014b
- BE- Basic (2012-2016): Competition- mediated discovery of cryptic genes coding for novel antimicrobials
Within this project we aim to develop and apply high throughput screening to select for soil- and wood-inhabiting bacteria that only produce antimicrobials when confronted with other microbes. In addition to the screening for novel antibiotics and their genes, we will focus on the signals involved in the expression of antibiotics genes as they may trigger antibiotic production in bacteria previously thought not to produce antibiotic compounds.
Olaf Tyc (Ph.D project)
- Vidi Project (2012- 2018): The secrets of success: the best bacterial competitive strategies in the rhizosphere
The rhizosphere- the narrow soil zone adjacent to plant roots is a hot-spot of microbial activity because of input of root-derived organic compounds. The diversity of soil microbes that are able to metabolize these compounds is huge but only a sub-set is successful in exploiting them. The composition of this sub-set, representing the most successful competitors, differs with rhizosphere conditions. This may point at the success of different competitive strategies under different conditions. Interference competition is generally occurring between rhizosphere bacterial species and does mostly involve the production of secondary metabolites suppressing opponents. The properties of these metabolites are important determinants of the success of a rhizosphere bacterial species in a particular situations. With 3 integrated sub-projects different aspects of successful interference competition will be examined.
Current group-members: