UBC Theses and Dissertations
Branch production and fragmentation in the conidia of Pseudozyma prolifica Wiebe, Marilyn Gail
The hyphomycete Pseudozyma prolifica Bandoni was grown in batch and continuous liquid cultures to determine the influence of growth rate and nutrition on conidium development. In batch culture, a period of elongation and branch formation, followed by fragmentation, was typically observed. The stage of branch formation was almost completely eliminated when the amino acids phenylalanine, glutamic acid, or asparagine were substituted for nitrate. Substituting citric acid for glucose had a similar effect. Branch formation was enhanced in sucrose + nitrate medium. In batch cultures, branched growth occurred at the start of the exponential growth phase. In continuous culture, the extent of branching was dependent on the specific growth rate. Maximal branching was observed at growth rates near the maximum. Growth by elongation and "bud" formation was predominant at low growth rates, as at the end of the log phase in batch cultures. The conidia were also examined using fluorescence and electron microscopy. Staining with wheat germ agglutinin conjugated to Fluorescein Isothiocyanate indicated that some intercalary growth occurs.
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