The Sporulation of Penicillium notatum Westling in Submerged Liquid Culture: I. THE EFFECT OF CALCIUM AND NUTRIENTS ON SPORULATION INTENSITY

The growth and sporulation of Penicillium notatum Westling inshaken submerged culture has been studied. Sporulation occurredonly when calcium ions were added to the basal sucrose-mineralsalts medium. Concentrations of 5 p.p.m. or less of calciumwere ineffective and at least 35 p.p.m was necessary for themaximum degree of sporulation. The replacement of calcium inthe medium by strontium or barium enabled sporulation to occur,although these metal ions were less effective than calcium inthe order. The calcium requirement for sporulation diminishedas the total nutrient concentration was lowered and was similarlyreduced if the concentration of the nitrogen source alone (sodiumnitrate) was lowered, whereas reductions in the levels of othersingle nutrients caused relatively small alterations in thecalcium requirement. Lowering the concentration of the nitrogensource caused increased sporulation in the presence of bothlimiting and non-limiting levels of calcium.