Lichen-associated bacteria transform antibacterial usnic acid to products of lower antibiotic activity

Lichens are specific symbiotic organisms harboring various microorganisms in addition to the two classic partners (algae or cyanobacterium and fungus). Although lichens produce many antibiotic compounds such as (+)-usnic acid, their associated possess ability colonize an environment where antibiosis exists. Here, we have studied behavior of several lichen-associated bacterial strains presence a known lichen compound. The effect this compound was firstly evaluated on growth metabolism three bacteria, thus showing its inhibit Gram-positive bacteria. This inhibition not thwarted with usnic acid producer strain Streptomyces cyaneofuscatus. biotransformation metabolite also studied. An ethanolamine derivative low activity highlighted chemical profiling, using HPLC-UV combined resolution mass spectrometry. These findings highlight way which some develop resistance mechanisms. A methylated annotated molecular networking method, interest computer-based approach studies.