Debaryomyces Research Articles

New Record of Debaryomyces nepalensis in Taiwan

Debaryomyces nepalensis, a new record belonging to the genus Debaryomyces was isolated from the soil in northern Taiwan. All the strains examined had typical morphological and physiological characteristics to D. nepalensis. Meanwhile, the sequences of D1/D2 domain of large subunit rRNA genes of the strains were identical to that of D. nepalensis.

Root Surface Culturable Microflora Associated with Post Harvest Spoilage of Sweet Potato (Ipomoea batatas L.)

The root surface microflora of sweet potato consists of a small group of fungi, i.e. Aspergillus nirger, A. awamori, Botryodiplodia theobroinae, Cochlobolus lunatus (Curvularia lunata), Fusarium oxysporum, F. pallidoroseum, Penicillium decumbens, Rhizopus oryzae and Ptichoderma sp., three yeast species i.e. Debaryomyces hansenii, Pichia anomala and Saccharomyces cerevisiae, and some bacteria. The fungal isolates i.e. B. theobromae, Fusarium spp. and R. oryzae were aggressively pathogenic on freshly harvested sweet potato tubers causing extensive rots while Cochliobolus lunatus (Curvularia lunata) was mildly pathogenic. Species of Aspergillus, Penicillium and Trichoderma were found as secondary invaders on tubers previously colonized by the mentioned species. The three yeast species and bacteria were not pathogenic at all for sweet potato. Removal of the rhizoplane microflora by surface sterilization using 1% sodium hypochlorite solution prevented fungal rot, thus extending the storage life of the tubers.

Flocculation of the yeast Candida famata (Debaryomyces hansenii): an essential role for peptone.

Aggregation of Candida famata (Debaryomyces hansenii) is consistent with being a form of lectin-mediated yeast flocculation. Flocculation of C. famata is unusual in that it requires the presence of peptone, either in the growth medium or added later to harvested cells in buffer. Flocculation after peptone addition was rapid, being largely complete within 10 min. Heat-killed cells also flocculated, arguing for direct participation of peptone in the flocculation binding mechanism. Flocculent C. famata cells progressively lost the ability to flocculate when washed with EDTA. Flocculation was fully restored by peptone addition; calcium addition was without effect. C. famata cells were able to agglutinate erythrocytes in the presence or absence of peptone. Pronase E-treated yeast lost both the ability to haemagglutinate and self-flocculate. Haemagglutination was not diminished by progressive EDTA washing, suggesting that surface lectins remained present and active on the yeast cell walls. Non-flocculating C. famata cells mutually flocculated with non-flocculent Schizosaccharomyces pombe cells, shown to have surface-exposed galactose residues. Mutual flocculation was lost following treatment of C. famata with Pronase E. It was concluded that the cell wall of C. famata contains lectins enabling haemagglutination and mutual flocculation but lacks carbohydrate receptors for these lectins. This yeast self-flocculates only via bridging multi-valent carbohydrates; these being present in peptone.

Production of xylitol from raw wood hydrolysates by Debaryomyces hansenii NRRL Y-7426

Production of xylitol from raw wood hydrolysates by Debaryomyces hansenii NRRL Y-7426

DEBARYOMYCES INFECTION IN VERMONT.

DEBARYOMYCES INFECTION IN VERMONT.