The Sporulation ofPenicillium notatumWestling in Submerged Liquid Culture

Abstract

The growth and sporulation of Penicillium notatum Westling in shaken submerged culture has been studied. Sporulation occurred only when calcium ions were added to the basal sucrose-mineral salts medium. Concentrations of 5 p.p.m. or less of calcium were ineffective and at least 35 p.p.m was necessary for the maximum degree of sporulation. The replacement of calcium in the medium by strontium or barium enabled sporulation to occur, although these metal ions were less effective than calcium in the order. The calcium requirement for sporulation diminished as the total nutrient concentration was lowered and was similarly reduced if the concentration of the nitrogen source alone (sodium nitrate) was lowered, whereas reductions in the levels of other single nutrients caused relatively small alterations in the calcium requirement. Lowering the concentration of the nitrogen source caused increased sporulation in the presence of both limiting and non-limiting levels of calcium.