Scientists Discover Three Powerful Biosurfactant-Producing Bacteria in India’s Thar Desert

Scientists Identify High-Performance Biosurfactant-Producing Bacteria from the Thar Desert

A new study published in Antonie van Leeuwenhoek reports the discovery of three potent biosurfactant-producing bacteria isolated from the arid soils of the Thar Desert in Rajasthan, India. The desert’s extreme heat, dryness, and nutrient scarcity make it an ideal environment for extremophilic microbes capable of producing robust surface-active compounds.

Researchers collected soil samples from sand dunes in Churu, Rajasthan, and isolated ten morphologically distinct bacterial strains. These isolates were screened using multiple biosurfactant detection assays, including drop-collapse (DC), emulsification index (EA24), surface tension (ST), and interfacial tension (IFT) tests. Three isolates—S4, S6, and S9—demonstrated significant biosurfactant activity.

Among these, isolate S9 exhibited the strongest activity with an EA24 of 57.16%, surface tension reduction to 24.61 mNm⁻¹, and interfacial tension of 4.42 mNm⁻¹. Isolates S6 and S4 also performed strongly, recording EA24 values of 54.13% and 51.83%, respectively.

Using 16S rRNA gene sequencing, the researchers identified the three strains as:

Cytobacillus kochii (S4)
Acinetobacter soli (S6)
Bacillus cereus (S9)

These species are known for their metabolic versatility, and their ability to thrive under high temperature, salinity, and desiccation aligns with the environmental pressures of the Thar Desert.

The findings highlight the desert as an underexplored reservoir of extremophilic microbes with valuable biotechnological potential. The identified strains demonstrated strong emulsification properties and substantial reductions in surface and interfacial tension, traits important for applications such as hydrophobic pollutant degradation, soil moisture improvement, and sustainable agricultural practices.

While the study was conducted under laboratory conditions, the authors emphasize the need for future field-based evaluations and investigations into environmental factors influencing biosurfactant production.

Reference

Thakur, S.S., Lone, A.R., Ratnasari, A. et al. Isolation and characterization of biosurfactant-producing bacteria from the Thar Desert. Antonie van Leeuwenhoek 118, 177 (2025). https://doi.org/10.1007/s10482-025-02189-3