Studies of unicellular micro-organisms Saccharomyces cerevisiae by means of Positron Annihilation Lifetime Spectroscopy

Positron and its bound state positronium are applied since a few decades as a tool in material investigations. Especially, positron annihilation lifetime spectroscopy (PALS) is widely used, as it gives a possibility to correlate the mean o-Ps lifetime value with cavity size in which annihilation undergoes. The relationship called Tao-Eldrup model [1, 2], describing o-Ps pick-off annihilation, assumes free space as a spherical potential well in which positronium is trapped. It allows to fi nd the dependence of the mean o-Ps lifetime value in the trap and its radius. Some modifi cations concerning other shapes and larger sizes [3–7] widespread the application area for new classes of media such as porous materials containing elongated pores, sometime opened to the surface. PALS allows to study many properties of investigated materials such as the presence of defects, thermal expansion, temperature of phase transition in polymers, processes of gases, or steams sorption in pores. However, it was applied in a very limited number of papers concerning living biological material [8, 9]. Some applications in biological system were described by Jean and Ache in 1977 [10] and were further studied in Jean’s group. They focused on the studies of healthy and abnormal skin samples [11, 12] and reported that S parameter from Doppler broadening (DB) technique is correlated with broadly defi ned level of skin damage. Over past few years biological systems appeared in interest Studies of unicellular microorganisms Saccharomyces cerevisiae by means of positron annihilation lifetime spectroscopy Ewelina Kubicz, Bożena Jasińska, Bożena Zgardzińska, Tomasz Bednarski, Piotr Białas, Eryk Czerwiński, Aleksander Gajos, Marek Gorgol, Daria Kamińska, Łukasz Kapłon, Andrzej Kochanowski, Grzegorz Korcyl, Paweł Kowalski, Tomasz Kozik, Wojciech Krzemień, Szymon Niedźwiecki, Marek Pałka, Lech Raczyński, Zenon Rajfur, Zbigniew Rudy, Oleksandr Rundel, Neha Gupta Sharma, Michał Silarski, Artur Słomski, Adam Strzelecki, Anna Wieczorek, Wojciech Wiślicki, Marcin Zieliński, Paweł Moskal