Gene mining for novel enzymes and drugs from marine environments

It has been estimated that > 99 % of microorganisms observable in nature typically can not be cultivated by using standard techniques. Thus, a large fraction of the diversity in an environment is still unknown. Our approach is to use the genetic diversity (DNA) of the micro-organisms in a certain environment as a whole to encounter new genes and gene products for various purposes (e.g. new biocatalysts; microbial drug molecules; novel components, which prevent biofilm formation). The genetic diversity is accessed by isolation of DNA followed by direct cloning of functional genes from environmental samples. In Kiel, we are mainly focusing on marine environments, which are highly diverse (collaboration with the GEOMAR, Kiel).

We are interested to increase our knowledge on marine microbial consortia and biofilms on biological and non-biological surfaces. In order to understand the ecological aspects and interspecies communication in mixed biofilms on a molecular level we are using metagenomic technologies. Here one focus is to identify novel components which interfere with biofilm formation by degradation, suppression or inhibition of signal molecules for interspecies and intraspecies communication and thus prevent mixed biofilm formation. (Funded by the BMBF, Chembiofilm

 Control biofilm  Biofilm expressing a QQ-ORF

Friends or Foes? Microbiota – host interactions at the base of the metazoan tree

In collaboration with the Medical Department (Institute for Clinical Molecular Biology) and the GEOMAR we analyze the mechanisms of host-microbial interactions in marine environments. The goal of this project is to develop model systems, which may lead to understand human barrier diseases (see also 'The Future Ocean').

One model system is the widely distributed jelly fish Aurelia aurita, which shows a di-phasic life cycle alternating between free-living pelagic sexual (medusa) and sessile benthic asexual (polyp) phases. We mainly focus on the microbial microbiota associated to the surface of A. aurita evaluating (i) the role of the environment, genetic background, external disturbance and challenge by opportunistic pathogens for the establishment and specificity of the microbiota, as well as (ii) the functional role(s) of the associated microbiota for the host. Ultimately we aim to get detailed insight into the interactions between the host and its microbiota.