高圧力下の微生物活性

圧力ショック酵母の熱測定とレーザーの生体刺激効果

抄録

Biocalorimetry is one of the powerful and convenient tools to evaluate microbial activities under high pressure. The method is mainly based on the fact that the heat evolved is strictly proportional to the metabolic activity, and the magnitude of calorimetric signal is employed as an index to express the biological activities. This method was adopted in order to investigate the thermotolerance of heat- and pressure-shocked yeast. The effects of non-reducing disaccharide trehalose on the stress response of yeast were also studied by a colony counting method and calorimetry. The biostimulation effect of a He-Ne laser was used for the recovery of yeast activity under high pressure up to 100 MPa. At 50 MPa and 30°C, the growth of unirradiated yeasts was inhibited entirely, however, the viable cell numbers of irradiated ones were increased and the rate of the increase in number of viable cells corresponded to that of the inrradiated ones at 0. 1 MPa.