What it is
Aureobasidium pullulans is a yeast-like fungus best known for producing beta-glucan and the polysaccharide pullulan, and its ferment filtrate is the liquid recovered after fermentation. In cosmetics the filtrate is valued for its polysaccharide content, which helps condition and hydrate skin and can leave a smoothing, lightly film-forming feel. In a protective day cream it contributes to a supple, moisturized skin surface and does not provide ultraviolet protection.
Safety & warnings
Ferment filtrates of this type are generally well tolerated in skin care. Because it is a microbial fermentation product, individuals with known sensitivities to yeast- or fungus-derived ingredients should use appropriate caution and consider patch testing. It is not a recognized fragrance allergen and is not an oil, so comedogenicity is not a typical concern.
Origin & sourcing
Biotechnological; the filtered liquid obtained by fermenting the fungus Aureobasidium pullulans, retaining soluble polysaccharides and metabolites.
Questions everyone asks
What is Aureobasidium pullulans ferment filtrate?
It is the filtered liquid from fermenting a yeast-like fungus, rich in skin-conditioning polysaccharides such as beta-glucan and pullulan.
What does it do in a sunscreen or day cream?
It acts as a conditioning, hydrating, lightly film-forming ingredient that supports a smooth, supple skin feel; it is not a UV filter.