[7] It can grow slowly without additional solute in the growth medium, and form small, reddish-brown, powdery colonies.

The species differ in their conidial size, xerotolerance, halotolerance, chaotolerance, growth temperature regimes, extracellular enzyme activity profiles, and secondary metabolite patterns.

[10] The earliest synonym of W. sebi recorded is Torula epizoa Corda, which is originated from salty meat in Belgium in 1829.

[2] Frank and Hess studies the Sporendonema epizoum (synonym of W. sebi) that grow on dried salted fish and suggested it to be halophilic in 1941.

Wallemia sebi is now recognized as xerophilic fungi because of independence of solute used to lower the water activity.

[11] This species is abundant in house dust and suspected to be a causative agent for atopic diseases in the study conducted by Sakamono et al. in 1989.

[13][14] (Wood 1990 and Frank et al. 1999) Wallemia sebi was suggested to cause allergological problems resulting in farmer's lung disease in 1998.

[2] Wallemia sebi can grow slowly on specialized fungal media with low water activity[15] without additional solutes.

[2] On agar, W. sebi forms small brown colonies with a fine velvety texture, that have long rows of spores that may round up and become free at maturity.

Wallemia sebi produces secondary metabolic compounds like walleminol, walleminone,[16] wallemia A and C, and azasteroid UCA1064-B[16] A newly conducted study also observes a light yellow oil-like metabolite that produced by W. sebi called wallimidione (1-benzylhexahydroimidazo[1,5-alpha] pyridine-3,5-dione), and it might be the most toxic of all metabolic productions.

[13] They suggested that walleminol A causes toxic effects in range of in vitro systems such as mammalian cell lines, protozoa and brine shrimp.

[16] Secondary metabolite production is very dependent on the growth medium, therefore W. sebi might not produce mycotoxins in foods or feeds.

Along with other xerophilic fungi, they cause loss of flavor and volatile components, production of off-flavors, and clumping in ground spices.

[23] Since the indoor environments that is suitable for human habitation often satisfy the growth requirement for W. sebi, W.sebi would be observed in building wallpaper if the water activity is not controlled as low.

Poor moisture control (e.g. fail to dry material in constructions) will result in the growth of hydrophilic and xerophilic fungi.

[23] Furthermore, it is more challenging to prevent the growth of xerophile than hydrophilic fungi, because it requires the water activity to be extremely low.

[23] For example, dry the building material to the extent of under 0.9 aw water activity only will prevent the growth of hydrophilic fungi, but not capable of controlling the colonization of xerophile.

[23] Therefore, in order to prevent the growth of W. sebi, the water activity should be less than 0.65 aw, which can be achieved by drying the materials within forty-eight hours under normal building temperatures.

[12] The health effect of chronic exposure to airborne fungi in indoor environment is known to be associated with both allergens and inflammatory compounds.