The Nutrition of Penicillium Digitatum Sacc.

SUMMARY

Cultivation of P. digitatum under the conditions of agitation and aeration on a mechanical shaker resulted in an acceleration of initial growth. In addition, replicate values obtained were more comparable than corresponding values obtained in stationary cultures, since they did not vary as much.

Peptone, urea and asparagin, both with and without added yeast extract, in shaken flasks proved to be satisfactory nitrogen sources for the growth of P. digitatum. Inorganic ammonium compounds were likewise utilized as nitrogen sources for growth, both with and without added yeast extract; however, nitrates (with the exception of ammonium nitrate) were utilized poorly, or not at all.

On the basis of a single sampling date, or rarely two, P. digitatum can utilize D-xylose, L-arabinose, D-glucose, D-fructose, D-mannose, D-galactose, sucrose and cellobiose very efficiently as carbon sources: L-rhamnose and lactose allowed moderate growth; and D-mannitol, maltose and dextrin were utilized poorly. No growth occurred when inulin and soluble starch were the carbon sources. Citric and malic acids could be utilized to a certain extent, but fumaric, tartaric, lactic, acetic and oxalic acids could not be utilized.

P. digitatum strain NRRL No. 1202, strain NRRL No. 786 and an isolate from grapefruit do not require the addition of growth substances to the basal medium for good growth. However, if yeast extract or a vitamin mixture of biotin, thiamin, pyridoxine, and calcium pantothenate are added to the basal medium, the initial growth of the fungus is accelerated.