Microcalorimetric studies of the action of NA2SeO3 on the growth of Halobacterium halobium R1

Abstract

The effect of Na2SeO3 on the growth of Halobacterium halobium R1 was investigated by means of microcalorimetry at 37°C. The biological response to toxicants is observed as the inhibition of the rate constant of growth of living cells. A low concentration of Na2SeO3 stimulated the growth of H. halobium R1, and a high concentration of Na2SeO3 inhibited the growth of H. halobium R1. Toxicity may be expressed as the half-inhibition concentration (IC50). The rate constants of growth (k) and the concentrations of Na2SeO3 (c) shows a linear relationship: k = 1.790 × 1006 - 2.27 × 10-3 c. The value of IC50 obtained from the accompanying figure of I-c is 679 μg/mL.