Chair of Technical Microbiology, TU Munich, Freising, Germany
Photobacteria were previously known as marine bacteria and are typically found in open-ocean and deep-sea environments as either free-living bacteria or in symbiosis with marine organisms. Unexpectedly, employing an advanced metatranscriptomic approach directly from meat, we found that high numbers of gene transcripts mapped to photobacteria. Furthermore, we were able to predict the in situ metabolism of photobacteria, which revealed production of unwanted and harmful spoilage metabolites. Consequently, a novel targeted selective isolation approach was developed in order to isolate the hitherto uncultured photobacteria from meats. The adapted procedure revealed that photobacteria are pervasive constituents of the meat spoiling microbiota of various MAP and VP meats, and led to the discovery of a novel species, Photobacterium carnosum, isolated from a terrestrial environment. In conclusion, the combined culture-dependent and culture-independent approach demonstrated the abundance of multiple photobacteria on fresh meats, which were hitherto neglected regarding their importance and relevance to meat spoilage.