Technological breakthroughs

An international research team has published a comprehensive review of biosurfactants, evaluating their potential as a sustainable alternative to synthetic surfactants currently used widely in industry.

What are biosurfactants?

Biosurfactants are amphiphilic compounds produced by microorganisms from renewable feedstocks. Thanks to their ability to reduce surface tension between liquid phases or between liquids and solids, they can replace petroleum-based surfactants, which are often poorly biodegradable and toxic to aquatic and terrestrial ecosystems.

The authors classify biosurfactants into two major groups based on molecular weight. Low-molecular-weight biosurfactants, such as glycolipids and lipopeptides, are highly effective at reducing surface tension and emulsification. High-molecular-weight biosurfactants, including emulsan and liposan, possess complex polymeric structures suitable for applications requiring long-term emulsion stability.

Production from waste materials

One notable aspect of the review is the use of industrial and agricultural waste as fermentation feedstocks. Microorganisms such as Pseudomonas, Bacillus, Candida, and Lactobacillus can convert waste cooking oil, food-processing residues, and lipid-containing wastewater into valuable biosurfactants.

The process involves three main stages: microorganisms first break down waste oil into glycerol and free fatty acids; these products then enter parallel biosynthetic pathways to generate rhamnose sugars and lipid units; finally, the enzyme rhamnosyltransferase links these two components to form rhamnolipids — one of the most extensively studied biosurfactants.

In terms of productivity, Candida bombicola cultivated on waste frying oil achieved sophorolipid yields of up to 221.9 g/L, while Enterobacter sp. UJS-RC grown on corn steep liquor produced 4.4 g/L of rhamnolipid with an emulsification index of 75%.

Applications across multiple sectors

The review highlights the broad application spectrum of biosurfactants. In environmental remediation, rhamnolipids produced by Pseudomonas aeruginosa SR17 degraded up to 86% of total petroleum hydrocarbons in contaminated soil after six months of treatment, outperforming the commonly used synthetic detergent sodium dodecyl sulphate (SDS). Lipopeptides from Bacillus species can remove zinc and lead from acidic soils, supporting the restoration of heavy-metal-contaminated land.

In agriculture, rhamnolipids improve the rhizosphere environment of cotton plants grown in saline desert soils, increasing plant growth by 3.3–9%, while also exhibiting antifungal activity against several crop pathogens. In the food industry, mannosylerythritol lipid-A (MEL-A) improves the rheological properties of frozen dough and creates a more uniform bread structure. In medicine and pharmaceuticals, surfactin and fengycin from Bacillus subtilis are being investigated as vaccine adjuvants and anticancer agents, while sophorolipids have demonstrated activity against HIV, influenza viruses, and Epstein–Barr virus.

In the oil extraction industry, biosurfactants remain stable at temperatures up to 100°C and in saline environments, improving enhanced oil recovery after water flooding more effectively than conventional surfactants.

Barriers to commercialization

Despite their considerable promise, biosurfactants still face several barriers to large-scale industrial adoption. High production costs due to complex fermentation processes and expensive purification steps remain the primary challenge.

Variability in feedstock quality — particularly with agricultural waste — also affects process stability. From a regulatory perspective, agencies such as the Food and Drug Administration and the European Medicines Agency require toxicity and microbial impurity testing for biosurfactants intended for pharmaceutical and food applications, slowing the approval process.

Current research directions include genetic engineering of microbial strains to improve productivity, the design of continuous fermentation systems with real-time monitoring, and the application of AI-assisted metabolic modeling. Life cycle assessment (LCA) is also being integrated into process design to optimize environmental performance.

At present, around 15 companies worldwide are commercializing biosurfactants, including BASF, Evonik Industries, and Givaudan, for applications ranging from detergents to cosmetics and environmental remediation.

The review article was published in Springer Nature’s journal Discover Applied Sciences in October 2025.

DOI: 10.1007/s42452-025-07603-z