A new yeast endosymbiont - implanting E. coli into S. cerevisiae

1.5 billion years ago, a metabolically limited early eukaryote ingested bacteria, rendering it capable of occupying new niches. But since this last endosymbiotic event, stably inheritable associations between bacteria and single host cells did not happen again. The generation of an exchangeable synthetic intracellular symbiont aims at implanting a bacte-rial cell into a yeast cell and replay nature. In a first step, a protocol to transform S. cerevisiae protoplasts with bacteria was developed. Next, readout to discriminate positive events from empty yeast cells will be developed. In parallel, a mutual dependency of host and endosymbiont is engineered. The exchange of essential vitamins, as well as positive selection with transcriptional activation by the partner organism, are investigated.