According to SCIAM

Museums around the world are facing a growing and largely invisible threat: extremophile molds capable of surviving and proliferating in environments previously thought to be hostile to fungal life. New research and conservation reports indicate that these highly adaptable fungi are actively damaging cultural heritage objects, from ancient manuscripts to paintings, textiles, and archaeological artifacts.
Unlike typical indoor molds, extremophile fungi can tolerate conditions such as low humidity, high salinity, limited nutrients, and fluctuating temperatures. Their resilience is forcing conservators to rethink long-held assumptions about preservation, environmental control, and long-term storage.

What Are Extremophile Molds

Extremophile molds are fungi that thrive in conditions considered extreme by conventional biological standards. While most molds require warmth, moisture, and organic material, extremophile fungi can persist where resources are scarce and environmental stress is high.

These organisms have been documented in deserts, polar regions, salt flats, deep caves, and even nuclear reactor cooling systems. Their ability to survive in low-water or nutrient-poor conditions makes them particularly problematic for museums, which often rely on controlled environments to suppress biological growth.

In recent years, researchers have confirmed that some extremophile molds are capable of colonizing museum artifacts once believed to be biologically stable.

Why Museums Are Vulnerable

Museums aim to protect collections by maintaining stable temperature, low humidity, and minimal light exposure. Ironically, these very conditions may favor extremophile fungi that have evolved to exploit marginal environments.

Artifacts made of paper, parchment, wood, leather, textiles, and pigments contain trace organic compounds that can serve as nutrients. Even microscopic residues—such as oils from handling, binding agents in inks, or airborne dust—can sustain fungal growth over time.

Damage to Cultural Heritage Objects

The impact of extremophile mold growth extends beyond cosmetic damage. Fungal colonization can weaken fibers, alter pigments, and chemically degrade surfaces.

Observed damage includes:

discoloration and staining of paper and textiles
weakening and embrittlement of parchment and leather
pigment alteration in paintings and manuscripts
surface pitting and material loss

Because many artifacts are unique and irreplaceable, even minor deterioration represents a permanent loss of cultural heritage.

How Extremophile Molds Survive Harsh Conditions

Scientists studying these fungi have identified several survival strategies. Extremophile molds often produce protective pigments, thick cell walls, and specialized enzymes that allow them to withstand dehydration, radiation, and chemical stress.

Some species can enter dormant states for long periods, reactivating when conditions become even slightly favorable.

Climate Change and Increased Risk

Climate change is emerging as a significant factor in the spread of extremophile molds. Rising global temperatures, increased humidity variability, and more frequent extreme weather events place additional stress on museum infrastructure.

Flooding, heat waves, and power outages can disrupt climate control systems, creating windows of opportunity for fungal colonization.

Common Extremophile Molds Identified in Museums

Studies have identified several fungal species associated with damage to cultural heritage materials. These include:

Many of these species are xerophilic or halotolerant.

Conclusion

Extremophile molds represent a significant and evolving threat to museum collections. Their ability to survive in low-moisture, low-nutrient environments undermines long-standing assumptions about artifact safety and highlights vulnerabilities in current preservation practices.

As climate pressures intensify and fungal research advances, museums face a critical challenge: adapting conservation strategies to protect humanity’s shared cultural heritage from organisms that thrive where others cannot.