Effects of the Alkali Metal Chlorides on Spore Germination, Growth, and Carotenogenesis of Phycomyces blakesleeanus

Abstract

Nonheated asexual spores of P. blakesleeanus germinated to the extent of 80-90% in a basal glucose-potassium-acetate-ammonium-sulfate medium. Omission of potassium acetate reduced germination to a few per cent. Addition of NaCl (8.6 m moles/liter) to the basal medium reduced germination greatly. Heat-treated spores (3 minutes at 50[degree]) germinated about equally well in the basal medium whether NaCl was present or not. Germination of nonheated and heat-treated spores in incomplete media containing acetate was reduced by the addition of NaCL The inhibitory effect of NaCl on the germination of nonheated spores was overcome by increasing the concentration of potassium acetate. NaCl was effective in reducing germination of nonheated spores only when it was added to the basal medium within 30 minutes after inoculation. When nonheated spores were used, severe inhibition of germination and early growth was obtained with LiCl and NaCl at a concentration of 8.6 m moles/liter, with CsCl at 17.2 m moles/liter, and with KC1 and RbCl at 34.4 m moles/liter. Heat-treated spores required higher concentrations for severe inhibition. LiCl, and CsCl and RbCl to a lesser degree, inhibited growth and carotenogenesis.