Team:Tartu TUIT/Demonstration
Our goal was to develop a system for controllable yeast self-lysis. We approached this goal by introducing glucan hydrolase genes whose expression can be controlled by addition of estradiol. Also, as the glucan hydrolases commonly used for yeast cell wall dissolution (for example in Zymolyase) are bacterial proteins, we modified their secretion signals to promote secretion of these proteins when expressed in yeast.
We were able to induce the lysis of yeast cells grown in the presence of estradiol under solid medium. As can be seen from the movie, after Ost1-Glc1 glucanase induction, some cells start to swell and, in some time, these cells are lysed, leading to the release of cellular content to the environment. We note that the self-lysis is relatively inefficient at this point, especially in liquid cultures. However, the lysis of a small percentage of cells followed in the time-lapse microscopy experiments is a proof of concept that inducible self-lysis can be achieved by controlled expression of cell wall degrading enzymes.
Video. Time-lapse microscopy. On the right side, there are induced Ost1-Glc1 expressing cells. The left side depicts uninduced Ost1-Glc1 expressing cells. Yellow arrows indicate cell lysis.