Alexander O. Brachmann

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Cultivated bacteria such as actinomycetes are a highly useful source of biomedically important natural products. However, such 'talented' producers represent only a minute fraction of the entire, mostly uncultivated, prokaryotic diversity. The uncultured majority is generally perceived as a large, untapped resource of new drug candidates, but so far it is(More)
Bacteria communicate via small diffusible molecules and thereby mediate group-coordinated behavior, a process referred to as quorum sensing. The prototypical quorum sensing system found in Gram-negative bacteria consists of a LuxI-type autoinducer synthase that produces N-acyl homoserine lactones (AHLs) as signals and a LuxR-type receptor that detects the(More)
Type II polyketide synthases are involved in the biosynthesis of numerous clinically relevant secondary metabolites with potent antibiotic or anticancer activity. Until recently the only known producers of type II PKSs were members of the Gram-positive actimomycetes, well-known producers of secondary metabolites in general. Here we present the second(More)
Members of the genus Xenorhabdus are entomopathogenic bacteria that associate with nematodes. The nematode-bacteria pair infects and kills insects, with both partners contributing to insect pathogenesis and the bacteria providing nutrition to the nematode from available insect-derived nutrients. The nematode provides the bacteria with protection from(More)
The production of the blue pigment indigoidine has been achieved in the entomopathogenic bacterium Photorhabdus luminescens by a promoter exchange and in Escherichia coli following heterologous expression of the biosynthesis gene indC. Moreover, genes involved in the regulation of this previously "silent" biosynthesis gene cluster have been identified in P.(More)
: With the development of several novel methods in genome sequencing, molecular biology, and analytical chemistry a new area of natural product chemistry is currently starting that allows the analysis of minute amounts of complex biological samples. The combination of these methods, as discussed in this review, also enables the analysis of bacteria living(More)
Photorhabdus is a genus of Gram-negative entomopathogenic bacteria that also maintain a mutualistic association with nematodes from the family Heterorhabditis. Photorhabdus has an extensive secondary metabolism that is required for the interaction between the bacteria and the nematode. A major component of this secondary metabolism is a stilbene molecule,(More)
Isopropylstilbene is a natural product from Photorhabdus luminescens TT01, with multiple biological activities. A mutant deficient in the production of both anthraquinones and cinnamic acid was constructed, thus giving a clean background according to UV detection. This anthraquinone and stilbene deficient (ASD) mutant was used in mutasynthesis experiments(More)