EFFECT OF LIGHT-INTENSITY ON RESPIRATION RATE OF SPIRULINA-PLATENSIS

Effects of light intensity and irradiation time on respiration rate in the dark period after irradiating are discussed. The specific respira tion rate of S. platensis in the dark is a constant value Q(1), up to 15-30 minutes, and then rapidly decreases to Q(2) after 30 minutes. Th e specific respiration rate Q(1) increases with light intensity. No si gnificant effect of Q(1) on irradiation time and Q(2) on light intensi ty is observed. The respiration rate for a long dark time, Q(0) (=1.2 mg-O-2.kg-Spirulina(-1).s(-1)), is almost the same as Q(2). The effect of the logarithmic mean light intensity I-1m[klx] on Q(1) is describe d by the following equation. Q(1)-Q(0) = 13 I-1m/15+I-1m.