The growth characteristics of Saccharomycopsis lipolytica: morphology and induction of mycelium formation

Abstract

When Saccharomycopsis lipolytica was grown on minimal medium supplemented with glucose or n-hexadecane, all the cells of the culture remained in the yeast form. In complex medium, a mixed morphology of yeast and mycelial forms appeared. If the cells were grown on minimal medium supplemented with N-acetylglucosamine as the carbon source, a reproducible system for the production of mycelium was obtained. Neither temperature, pH, nor several other carbon sources were able to induce a reproducible yeast–mycelial transition. Mycelium formation is maximal after 12–15 h of incubation (in the presence of N-acetylglucosamine) and decreases with longer incubating times when N-acetylglucosamine is exhausted. During mycelium formation a considerable increase took place in dry weight; the cell numbers, however, remained almost constant between 12–15 h. Electron microscopy shows mycelium with a smooth surface, a great amount of mitochondria and a low degree of branching.

Four Distinct Secretory Pathways Serve Protein Secretion, Cell Surface Growth, and Peroxisome Biogenesis in the Yeast Yarrowia lipolytica

“…Y. lipolytica is widely divergent from both S. cerevisiae and Schizosaccharomyces pombe (4,45). Y. lipolytica is a useful experimental organism to investigate cell surface dynamics, because it exists in developmentally distinct yeast and mycelial forms (50). The characteristic dimorphic transition from yeast to mycelium is dependent on both the growth medium composition and phase of growth and represents a specific developmental program that involves changes in cell morphology (ovoid to filamentous), mode of growth (exponential to linear), and mechanism of cell division (budding to septation) (see references 30 and 50 and this study).…”

“…The dimorphic transition from the yeast to the mycelial form is developmentally regulated in Y. lipolytica (50). We compared the cell morphologies of the wild-type strains and protein secretion-deficient mutants during growth in YEPD medium at 22 or 32°C.…”

HOY1, a Homeo Gene Required for Hyphal Formation in Yarrowia lipolytica

“…Cells were grown in YED (1% yeast extract, 1% glucose) or in appropriately supplemented minimal medium (MM; 0.67% yeast nitrogen base, 1% glucose). The induction of the yeast-hypha transition was carried out as described previously (54). Cells were grown on MM buffered with citric acid-sodium citrate (50 mM, pH 6.0) with glucose as a carbon source until they reached the exponential phase.…”

“…To gain insight into the developmental switch, we have developed an easy screen to obtain morphological mutants unable to form hyphae. The screening is based on the simple system for inducing the yeast-hypha transition reported previously by us (54). In the present work, we describe characterization of the HOY1 gene.…”

Intracellular precursors and secretion of alkaline extracellular protease of Yarrowia lipolytica.

“…lipolytica and S. cerevisiae are not closely related (46,68). Y. lipolytica exhibits dimorphic growth (59), grows on hydrocarbons (4), and differs in codon bias (18) and in organization of the rDNA genes (14,24,74). Y. lipolytica also secretes several enzymes in addition to AEP into the extracellular medium (9,51,54,80).…”