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Intraspecific variability and exopolysaccharide production in Aureobasidium pullulans
N A Yurlova1, I V Mokrousov, G S de Hoog
1Department of Microbiology, Chemical-Pharmaceutical Institute, St. Petersburg, Russia.
Antonie Van Leeuwenhoek
|July 1, 1995
Summary
This study differentiates black yeast species Aureobasidium pullulans and Hormonema using PCR-ribotyping and UP-PCR. Genetic and polysaccharide production analyses reveal distinct populations within Aureobasidium pullulans.
Area of Science:
- Mycology
- Molecular Biology
- Biochemistry
Background:
- Black yeasts, including Aureobasidasium pullulans and Hormonema species, are ubiquitous fungi with diverse ecological roles.
- Accurate species and population-level identification is crucial for understanding their biology and applications.
Purpose of the Study:
- To genetically differentiate strains of Aureobasidium pullulans and Hormonema species using molecular techniques.
- To investigate the genetic diversity and population structure within Aureobasidium pullulans.
- To compare polysaccharide production capabilities between Aureobasidium and Hormonema species.
Main Methods:
- PCR-ribotyping and universally primed PCR (UP-PCR) with subsequent hybridization were employed for genetic analysis.
- Restriction fragment length polymorphism (RFLP) analysis of amplified ribosomal DNA (rDNA) was performed.
- Exopolysaccharide production was assessed in liquid media with varying nitrogen sources.
Main Results:
- PCR-ribotyping distinguished four populations within Aureobasidium pullulans, largely consistent with UP-PCR/hybridization results.
- UP-PCR revealed greater genetic heterogeneity among the studied groups.
- Hormonema dematioides and Hormonema macrosporum formed a distinct group, differentiated from Aureobasidium pullulans by the presence of RsaI restriction sites in amplified rDNA.
- Aureobasidium pullulans strains produced significant exopolysaccharides, with variations dependent on nitrogen sources, while Hormonema species produced minor amounts.
Conclusions:
- PCR-based methods, particularly PCR-ribotyping with AluI and MspI, are effective for distinguishing populations of Aureobasidium pullulans and Hormonema species.
- Genetic diversity exists within Aureobasidium pullulans, influencing their polysaccharide production.
- The study provides a molecular basis for differentiating these black yeast species and understanding their population dynamics.