Wastewater and Industrial By-Products as Inputs for the Production of Microbial Exopolysaccharides and Surfactants

Dear Colleagues,

The generation of wastewaters and industrial by-products is expected to continue rising in the coming years, underscoring the urgent need for broader adoption of circular approaches for their valorization and recycling. Microbial exopolysaccharides (EPS) and biosurfactants are well-established industrial metabolites with growing demand and wide-ranging applications in food, cosmetics, pharmaceuticals, environmental management, and the oil industry. However, their production typically relies on conventional feedstocks such as glucose and sucrose, along with mineral supplements—factors that significantly increase upstream production costs.

Biotechnological approaches offer the possibility of reusing wastewater streams, industrial solids, and agri-food by-products such as crude glycerin as components of culture media for EPS and biosurfactant production. This strategy not only reduces reliance on conventional substrates but also transforms a waste management challenge into an opportunity for sustainable biomanufacturing.

When poorly managed, these waste streams are frequently discarded, contributing to environmental pollution, greenhouse gas emissions, and the depletion of valuable resources. Within the framework of the circular economy, however, they should be recognized as valuable raw inputs for sustainable bioprocesses. Recovering and transforming such by-products into EPS and biosurfactants represents a promising pathway toward biotechnological solutions and integrated biorefineries. Produced by bacteria and fungi, and more recently investigated in microalgae and cyanobacteria, these compounds offer remarkable potential across multiple sectors, ranging from enhanced oil recovery to food, cosmetics, pharmaceuticals, and agriculture. Beyond their functional versatility, their production from unconventional substrates enables substantial reductions in process costs, waste disposal, and environmental impact.

This Special Issue invites contributions that explore innovative strategies, scientific advances, and practical applications for the production and utilization of EPS and biosurfactants derived from waste streams. We particularly welcome studies that reinforce the vision of industrial ecology and green bioprocesses by addressing both practical and theoretical aspects of waste valorization.

We encourage submissions of original research articles and reviews in (but not limited to) the following areas:

1. Utilization of industrial and agri-food wastewaters for the production of EPS and biosurfactants by bacteria, fungi, microalgae, and cyanobacteria.
2. Valorization of industrial and agri-food by-products as culture medium constituents for EPS and biosurfactant production.
3. Novel methods and approaches to enhance the production of EPS and biosurfactants in waste-based media.
4. Physicochemical characterization and functional property improvements of EPS and biosurfactants obtained from unconventional substrates.
5. Application studies of EPS and biosurfactants derived from waste valorization – including food, cosmetic, and pharmaceutical uses, as well as environmental management.
6. Biorefinery concepts for the cyclical and integrated valorization of wastewaters and by-products, from feedstocks to EPS and surfactant products.
7. Production and exploitation of biosurfactants from wastewater and industrial residues for oil and gas industry applications.
8. Exopolysaccharide and biosurfactants from unconventional substrates: current advances and applications in enhanced oil recovery.
9. Biosurfactant production under extreme environmental conditions by alkali-, halo-, and thermophilic microorganisms using wastewater and industrial residues.

We look forward to receiving your contributions and advancing the knowledge frontier on exopolysaccharides and biosurfactants derived from alternative nutrient sources and integrated into biorefinery applications.

Prof. Dr. Paulo Fernando De Almeida
Dr. Igor Sampaio
Guest Editors

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• wastewater
• agri-food by-products
• exopolysaccharides
• biosurfactants
• microalgae biotechnology
• cyanobacteria
• fermentation
• bacterial bioprocesses
• enhanced oil recovery
• cosmetics
• food applications