Aureobasidium
Aureobasidium pullulans
Also known as: Pullularia, Black yeast
Initially cream to pink, smooth and slimy; develops dark pigmentation (melanin) as colony ages, becoming black and leathery
Aureobasidium at a Glance
Aureobasidium (Aureobasidium pullulans) is a low-risk, allergenic mold with moderate allergenic potential. It most often grows in window frames and glazing seals, bathroom caulking and sealants, painted surfaces with moisture exposure, and its primary health concerns are allergic reactions, skin sensitization, respiratory irritation. Confirmation requires laboratory analysis of collected samples — visual identification alone is not conclusive.
- Risk level
- Low
- Category
- Allergenic
- Common growth locations
- Window frames and glazing seals, Bathroom caulking and sealants, Painted surfaces with moisture exposure, Shower curtains and enclosures
- Primary health concerns
- Allergic reactions, Skin sensitization, Respiratory irritation
InspectaMold provides independent inspection and laboratory testing for Aureobasidium across Southeast Louisiana — assessment and documentation only. We do not perform remediation, so findings stay unbiased.
Gulf Coast Relevance: High
Frequently found in Louisiana and Mississippi Gulf Coast homes.
Appearance & Identification
Slimy, yeast-like initially; darkens and becomes leathery with age
Spreading, often in streaks following moisture paths
Requires high moisture; often found at active water sources
Growth Conditions
80-100%
0.90+ aw
50-86°F (10-30°C)
Common Growth Locations
Health Considerations
Allergic rhinitis, Mild respiratory irritation, Hypersensitivity reactions
moderate
Low to moderate; rare opportunistic pathogen reported in severely immunocompromised individuals
How Our Inspectors Detect It
Found where moisture content exceeds 20% or condensation is active
- •Window frames and seals
- •Bathroom caulking
- •Painted surfaces
- •Shower enclosures
- •Weatherstripping
- •Cold spots at windows
- •Condensation patterns
- •Thermal bridging at frames
Remediation Considerations
Surface mold on porous painted surfaces may be cleaned; heavily affected materials should be replaced
Clean with detergent; replace degraded caulking and sealants
Address condensation and improve ventilation before cleaning
Frequently Asked Questions
Is Aureobasidium (Aureobasidium pullulans) dangerous?
Aureobasidium is classified as a low-risk, allergenic mold with moderate allergenic potential. Primary health concerns include allergic reactions, skin sensitization, respiratory irritation. Low to moderate; rare opportunistic pathogen reported in severely immunocompromised individuals A professional assessment determines the extent and the right response for your property.
Where does Aureobasidium grow in Gulf Coast homes?
Aureobasidium commonly appears in window frames and glazing seals, bathroom caulking and sealants, painted surfaces with moisture exposure, shower curtains and enclosures. It thrives at 80-100% relative humidity with a water activity of 0.90+ aw, conditions that are common across humid Southeast Louisiana properties.
How do you identify Aureobasidium?
Initially cream to pink, smooth and slimy; develops dark pigmentation (melanin) as colony ages, becoming black and leathery Colonies are typically pink, brown, black with a slimy, yeast-like initially; darkens and becomes leathery with age texture. Generally low odor; slight musty smell when extensive Confirmation requires professional sampling and laboratory analysis rather than visual identification alone.
What does remediation of Aureobasidium involve?
Aureobasidium typically calls for standard containment. Surface mold on porous painted surfaces may be cleaned; heavily affected materials should be replaced Address condensation and improve ventilation before cleaning InspectaMold documents the conditions and provides an independent protocol so the underlying moisture source is corrected, not just the visible growth.
Concerned about Aureobasidium in your property?
InspectaMold provides independent, lab-backed mold inspection and air quality testing across Southeast Louisiana. Get an accurate identification and a clear plan.