THE EFFECT OF CALCIUM ON PROTOPLAST RELEASE FROM SPECIES OF ASPERGILLUS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 28  (112) , 69-80
Abstract
The effect of various osmotica and lytic enzyme treatments, on the release of stable protoplasts from A. niger and 2 strains of A. fumigatus, was investigated. Most osmotica supported protoplast release at a concentration of 0.6 M except for CaCl2 and Ca(NO3)2. Supplementation of 0.6 M KCl with 0.2 M CaCl2 enhanced release from both species, but depended upon strain of organism, concentration of osmoticum and enzyme system employed. More protoplasts were released at low concentrations of KCl and/or when chitinase was present in the digestion medium. This enhancement effect was concerned with the Ca2+ ion since addition of Ca(NO3)2 also gave a higher yield and EDTA severely depressed protoplast release. Further investigations suggested that the effect of Ca2+ was not primarily acting as a supplementary osmoticum or concerned with protoplast membrane stabilization. Experiments using 45CaCl2 showed that the enhancement effect was probably due to Ca2+ affecting chitinase activity.