Researchers open up new antibiotic reservoir

For the first time, scientists from Jena succeeded to cultivate and functionally characterize a total of 79 bacteria strains, which had previously received little attention. The microbes arise in the sea, where competition for nutrients is high at certain sites. Antimicrobial substances are an advantage here when it comes to survival.

Christian Jogler and his team at the Friedrich Schiller University in Jena talk about “dark microbial matter” in their article published in mid-November (Nature Microbiology). About 99 percent of all bacteria are considered “non-cultivable” and have barely been investigated as a result leaving only about 1% of all bacteria available for systematic drug screening.

The ability to produce antibiotics is not evenly distributed among bacteria. “It is mainly found in microorganisms with complex lifestyles, unusual cell biology and large genomes,” explains Jogler. “Such organisms produce antibiotic compounds and use them against other bacteria competing for nutrients and habitats”. A favourable spot to seek for potential antibiotic producers is hence wherever this competition occurs. Jogler and his team implemented robots and specially trained divers visiting such places. A total of ten sites in the sea were searched for so-called planctomycetes – in the Mediterranean Sea, the North and Baltic Seas, the Black Sea as well as the Atlantic, the Pacific and the Arctic Ocean. The scientists succeeded in bringing a total of 79 new Planctomycetes into pure culture. “Together, these pure cultures are comprised of 31 new genera and 65 new species,” adds Sandra Wiegand, author of the study.

In the analysis of these bacteria, the potential to produce small molecules such as antibiotics was investigated as well as the pathways of cellular signal processing. Suprisingly, when looking at cell division “some species divide quite differently compared to the rest of the critical pathogenic bacteria,” said Jogler. Above all, the study demonstrates that even supposedly “uncultivatable” bacteria can be obtained and characterised in pure culture. According to the authors of the study, many aspects of their current work can be transferred to other potential antibiotic producers. “The hypothesis-driven cultivation and holistic characterization is absolutely necessary in order to discover new aspects and to ensure new therapeutic paths,” highlights the scientist.

As far as the discovery of antimicrobial substances is concerned, the researchers are currently keeping a low profile. The analysis is currently underway and justified hope that it will be successful exists.

Jogler most recently conducted research at Radbout University Nijmegen in the Netherlands. In the summer of 2019, he accepted the occupation at the University of Jena as a W2 Professor of Microbial Interactions (Faculty of Biosciences).

First published at: https://transkript.de/news/forscher-erschliessen-neues-antibiotika-reservoir.html