Anita MacNelly

Personal Data:
Country of Origin: Germany
Start of PhD: November 2009
Institution: FSU

PhD Project:
Expression control and biosynthesis of dehalogenating enzymes from anaerobic soil bacteria in response to the interaction with aerobic halogenating fungi

Supervisor(s): G. Diekert (FSU)

Abstract:
The interaction between aerobic, lignin-degrading fungi and anaerobic bacteria in the course of halogenation and dehalogenation of organic compounds is the main focus in our research group. Lignin-degrading fungi of boreal forests show the ability to produce chlorinated organic compounds which can be subsequently dechlorinated under anoxic conditions by a heterogeneous group of soil bacteria. The key enzymes of the anaerobic dechlorination are reductive dehalogenases. It was shown very recently that the expression of the dehalogenase-related genes is controlled by the availability of the respective chlorinated substrate. To examine the functionality of this special microbial food chain following issues will be studied in more detail:
1) The ecological niche of dechlorinating bacteria in forest soil with respect to hot spots of lignin-degradation.
2) The induction of the reductive dehalogenase gene expression in response to the occurrence of chlorinated organic compounds formed upon fungal lignin-degradation.
3) The molecular mechanism of the signal transduction from substrate recognition to dehalogenase gene expression. Established techniques for the investigation of the tetrachloroethene (PCE) reductive dehalogenase found in Desulfitobacterium spec. will serve as basis for the characterization of transcriptional regulation of reductive dehalogenases genes.