Oxidative Damage and Mutation of DNA in Saccharomyces pastorianus Cells Treated with Pressurized Carbon Dioxide Microbubbles.

The effect of pressurized carbon dioxide microbubbles (CO2MB) on DNA in Saccharomyces pastorianus cells was investigated. The DNA concentration extracted from S. pastorianus cells treated with CO2MB by phenol extraction increased and decreased with the heating coil at 35 °C and at 40 and 45 °C, respectively. However, the density of DNA bands on agarose gel electrophoresis increased when using the heating coil at 40 and 45 °C. In addition, DNA fragmentation measured by quantitative PCR decreased with increasing temperature and prolonged exposure time in a heating coil. Furthermore, the generation of apurinic/apyrimidinic sites, an indicator of oxidative DNA damage, increased with increasing temperature or prolonged exposure time in a heating coil. In the phylogenetic tree constructed based on single-nucleotide polymorphisms obtained through DNA sequence analysis, S. pastorianus cells treated with CO2MB exhibited greater divergence from untreated with increasing temperature or prolonged exposure time in a heating coil. Similarly, insertions/deletions, showed genetic variations, of S. pastorianus cells treated with CO2MB increased with increasing temperature or prolonged exposure time in the heating coil. Therefore, these findings indicated that CO2MB induced partial oxidative damage and mutations of DNA in S. pastorianus cells, and the phenomena were suggested to be due to the oxidative stress generated within the cells.