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Carbohydrate stability during ageing in Penicillium expansum cell wall
1C.S.I.C. Instituto de Inmunología y Bilogía Microbiana, Madrid, Spain.
Microbiologia (Madrid, Spain)
|September 1, 1985
Summary
This study characterizes Penicillium expansum cell walls, revealing their composition changes with age. Glucose and chitin are key components, with alkali treatment isolating alpha-glucans.
Area of Science:
- Mycology
- Biochemistry
- Cell Biology
Background:
- Fungal cell walls are crucial for structural integrity and interaction with the environment.
- Penicillium expansum is a significant fungal species with implications in food spoilage and plant pathology.
- Understanding fungal cell wall composition is vital for developing targeted control strategies.
Purpose of the Study:
- To investigate the age-dependent changes in the cell wall composition of Penicillium expansum.
- To identify and quantify the neutral sugars, chitin, and protein components of the cell walls.
- To analyze the structural components released by alkali treatment.
Main Methods:
- Mycelial cultures of Penicillium expansum were grown for varying durations.
- Cell walls were isolated and subjected to compositional analysis (neutral sugars, chitin, protein).
- Gas-liquid chromatography was used for neutral sugar quantification.
- Alkali treatment was employed to fractionate cell wall components.
Main Results:
- Cell wall yield increased up to 13 days of incubation, then plateaued.
- 13-day-old cell walls comprised 65% neutral sugars, 10% chitin, and 10% protein.
- Glucose was the predominant neutral sugar (37%), followed by mannose and galactose (3-4% each).
- Chitin content remained constant throughout aging.
- Alkali treatment released approximately 30% alpha-glucan, leaving a residue of chitin and beta-glucan.
Conclusions:
- The composition of Penicillium expansum cell walls changes with mycelial age, with neutral sugars being the most abundant component.
- Glucose, chitin, and beta-glucans are significant structural elements of the Penicillium expansum cell wall.
- Alkali treatment provides a method for fractionating specific cell wall polysaccharides, aiding in structural elucidation.
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