Growth control of dry yeast using scalable atmospheric-pressure dielectric barrier discharge plasma irradiation

We have investigated the effects of plasma irradiation on the growth of dry yeast (Saccharomyces cerevisiae) using a scalable atmosphericpressure dielectric barrier discharge (DBD) device. NO of 380 ppm, NO₂ of 10 ppm and O₃ of 560 ppm were detected 1mm below the discharges, which were produced by the DBD plasmas. DBD plasma irradiation of 10 to 100 s enhances the growth of yeast in the lag phase, whereas that of 120 and 150 s suppresses the growth. O₃, NO₂ , photons, and heat generated by the plasma irradiation are not responsible for the growth enhancement of the dry yeast. Plasma etching has little effect on the growth of dry yeast cells. NO plays a key role in the growth enhancement of dry yeast cells. # 2012 The Japan Society of Applied Physics.