Biosurfactants: The Cleansers Made by Microbes

Most cleansing ingredients are made by chemically joining a fatty "tail" to a water-loving "head". But nature had the idea first: certain yeasts and bacteria make their own surfactants to help them feed on oily food. Fermented at scale, these biosurfactants are one of the most interesting sustainability stories in cosmetics.

What makes them different

A 2020 review in Cosmetics explains that biosurfactants are produced by microorganisms, biodegrade more readily than many synthetic surfactants, and are low- or non-toxic in almost all cases studied. It also notes the catch: production cost and yield are still barriers (Ahmadi-Ashtiani et al., 2020).

The market is growing quickly. One industry estimate valued it at about US$1.2 billion in 2022, rising toward US$1.9 billion by 2027, with personal care the fastest-growing use (GCI Magazine, citing MarketsandMarkets).

Meet the family

Sophorolipids: from yeast

Made by yeasts fed on sugar and plant oil. They're low-foaming but good at lifting oil, which makes them interesting for gentle face cleansers and micellar-style waters. A 2023 review describes their high biodegradability and low cytotoxicity in lab studies (with the honest caveat that much of the data is in vitro) (Adu et al., Molecules, 2023).

Try: Sophorolipid Biosurfactant (see the dictionary entry for levels).

Rhamnolipids: from bacteria

Produced mainly by Pseudomonas bacteria. They foam better and are being explored as mild co-surfactants.

Try: Rhamnolipids.

Surfactin: the lipopeptide

Made by Bacillus subtilis, the same family of bacteria behind natto. It's a surfactant built partly from amino acids, and it's extremely surface-active at tiny levels.

Try: Surfactin.

MELs: the conditioning one

Mannosylerythritol lipids are glycolipids made by certain yeasts, valued for a soft, conditioning skin feel.

Try: Mannosylerythritol Lipids.

How to formulate with biosurfactants

• Use them as team players. Biosurfactants shine as part of a blend. Pair them with mild amino-acid or glucoside surfactants, as in our gentle cleanser guide.
• Don't expect huge foam. Sophorolipids in particular are low-foaming. Many consumers link foam with cleaning, so manage expectations or add a foam booster.
• Check the supplied form. Some come as concentrated pastes or solutions, so dose by the supplier's "% active".
• Mind the pH: most sit comfortably around 4.5–6.5.
• They still need preserving in water-based products.

Honest claims

"Made by fermentation" and "readily biodegradable" (with supplier data to back it) are strong, fair claims. Be careful with "microbiome-friendly": our dictionary flags microbiome claims as needing substantiation.

The bigger picture

Biosurfactants cost more than conventional surfactants today. Like many biotech ingredients, prices tend to fall as production scales. For brands telling a genuine low-impact story, they're worth a test batch now.

Explore Biosurfactants and Surfactants & Cleansing Agents, or read about their fermentation cousins in our ferments post.