The exploitation of nature and the increase in manufacturing production are the cause of major environmental concerns, and considerable efforts are needed to resolve such issues. Oil and petroleum derivatives constitute the primary energy sources used in industries. However, the transportation and use of these products have huge environmental impacts. A significant issue with oil-related pollution is that hydrocarbons are highly toxic and have low biodegradability, posing a risk to ecosystems and biodiversity. Thus, there has been growing interest in the use of renewable compounds from natural sources. Biosurfactants are amphipathic microbial biomolecules emerging as sustainable alternatives with beneficial characteristics, including biodegradability and low toxicity. Biosurfactants and biosurfactant-producing microorganisms serve as an ecologically correct bioremediation strategy for ecosystems polluted by hydrocarbons. Moreover, synthetic surfactants can constitute additional recalcitrant contaminants introduced into the environment, leading to undesirable outcomes. The replacement of synthetic surfactants with biosurfactants can help solve such problems. Thus, there has been growing interest in the use of biosurfactants in a broad gamut of industrial sectors. The purpose of this review was to furnish a comprehensive view of biosurfactants, classifications, properties, and applications in the environmental and energy fields. In particular, practical applications of biosurfactants in environmental remediation are discussed, with special focus on bioremediation, removal of heavy metals, phytoremediation, microbial enhanced oil recovery, metal corrosion inhibition, and improvements in agriculture. The review also describes innovating decontamination methods, including nanobioremediation, use of genetically modified microorganisms, enzymatic bioremediation, modeling and prototyping, biotechnology, and process engineering. Research patents and market prospects are also discussed to illustrate trends in environmental and industrial applications of biosurfactants.

Spills involving fuels and lubricating oils in industrial environments caused by the fueling of machines, inadequate storage and the washing of equipment are significant sources of environmental pollution, impacting soil and water bodies. Such incidents alter the microbiological, chemical and physical properties of affected environments. The use of biosurfactants is an effective option for the cleaning of storage tanks and the remediation of contaminated soils and effluents. The scope of this work was to assess the production and application of a Starmerella bombicola ATCC 22214 biosurfactant to remediate marine and terrestrial environment polluted by oil. The production of the biosurfactant was optimized in terms of carbon/nitrogen sources and culture conditions using flasks. The performance of the biosurfactant was tested in clayey soil, silty soil, and standard sand, as well as smooth surfaces and industrial effluents contaminated with oils (fuel oils B1 for thermal power generation, diesel, and motor oil). The ideal culture medium for the production of the biosurfactant contained 2% glucose and 5% glycerol, with agitation at 200 rpm, fermentation for 180 h and a 5% inoculum, resulting in a yield of 1.5 g/L. The biosurfactant had high emulsification indices (86.6% for motor oil and 51.7% for diesel) and exhibited good stability under different pH values, temperatures and concentrations of NaCl. The critical micelle concentration was 0.4 g/L, with a surface tension of 26.85 mN/m. In remediation tests, the biosurfactant enabled the removal of no less than 99% of motor oil from different types of soil. The results showed that the biosurfactant produced by Starmerella bombicola is a promising agent for the remediation of environments contaminated by oil derivatives, especially in industrial environments and for the treatment of oily effluents.

Corrosion is the deterioration of metals due to environmental exposure. Commercial inhibitors used to control corrosion often contain heavy metal salts, which are highly toxic to both the environment and human health. A biosurfactant produced by the bacterium Pseudomonas cepacia CCT 6659 was tested as a corrosion inhibitor on carbon steel and galvanized iron surfaces. Matrices based on plant ingredients with different compositions were tested in a laboratory-constructed accelerated corrosion chamber (ACC) simulating a critical maritime atmosphere in conditions of 40 °C, 5% NaCl, and 100% humidity. The most stable matrix was selected for biosurfactant incorporation in different concentrations, expressed as critical micellar concentration (CMC), and was applied to metal surfaces to evaluate its ability to inhibit corrosion. Additionally, to evaluate the potential of the biosurfactant as a low-toxicity corrosion inhibitor additive in paint systems, iron and carbon steel samples were coated with three biosurfactant-containing commercial paints and subjected to critical atmospheric conditions for testing coating effectiveness. The formulation containing vegetable resin as a plasticizer, oleic acid, ethanol, and CaCO₃ was chosen to incorporate the biosurfactant. The addition of the biosurfactant at twice its CMC led to a reduction in carbon steel sample mass loss from 123.6 to 82.2 g/m², while in the galvanized iron plates, the mass loss decreased from 285.9 to 226.7 g/m² at the same biosurfactant concentration. When supplemented with the biosurfactant, the alkyd resin-based paint (A) ensured less mass loss in samples (46.0 g/m²) compared to the control without biosurfactant (58.0 g/m²). Using the paint formulated with oil-based resin (B), the mass loss decreased from 53.0 to 24.1 g/m², while with that based on petroleum derivatives (C), it decreased from 82.2 to 27.6 g/m². These results confirm the feasibility of using biosurfactants in biodegradable coatings, reducing the need for commercial corrosion inhibitors.

Microbiologically influenced corrosion (MIC) represents a critical challenge to the integrity of pipelines, piping, and metal structures in offshore environments, directly affecting the safety and operational costs of companies in the energy sector. However, conventional control methods, such as the use of chemical inhibitors, raise environmental and economic concerns. To face this problem, a biosurfactant produced by Pseudomonas cepacia CCT 6659 was tested as a biocorrosion inhibiting agent on carbon steel specimens immersed in seawater. For this purpose, static and dynamic conditions were simulated using different concentrations of the biosurfactant. Furthermore, analyses were performed using Scanning Electron Microscopy paired with Energy Dispersive Spectroscopy (SEM/EDS) to visualize the morphology of the biofilm and its chemical components. Laboratory tests indicated that the biosurfactant formulated in a 1:5 (v/v) ratio reduced the mass loss of test specimens (119.72 ± 2.64 g/m²) by no less than 57.3% compared to the control (280.28 ± 4.58 g/m²). Under dynamic conditions, the 1:2 (v/v) formulation showed greater protection, being able to reduce specimen corrosion (578.87 ± 7.01 g/m²) by 69.6% compared to the control (1901.41 ± 13.53 g/m²). SEM/EDS analyses revealed changes in surface composition and a reduction in corrosive elements associated with sulfur in the formed biofilms, which may be associated with a decrease in sulfate-reducing bacteria (SRB) activity, suggesting microbial inhibition by the biosurfactant. The results obtained in this study highlight the biosurfactant as a viable and ecological alternative to synthetic inhibitors, with potential application in the protection of metal structures exposed to corrosive environments in offshore energy systems, promoting greater durability, sustainability, and less environmental impact.

Corrosion remains one of the major contemporary technological challenges, causing significant economic, environmental, and operational impacts on industrial systems. Although it is a spontaneous process inherent to metals and their alloys, its progression can be significantly mitigated by appropriate protection strategies. Traditionally, synthetic inhibitors have been widely used; however, their toxicity, environmental persistence, and increasing regulatory restrictions have prompted a search for greener alternatives. Biosurfactants stand out as promising green anticorrosive agents, acting through the formation of adsorbed films, reduction in wettability, modification of the metal–medium interface, and, in some cases, antimicrobial effects that inhibit the formation of corrosive biofilms. This review presents an integrated analysis of the main corrosion mechanisms, including uniform, localized, galvanic, and microbiologically influenced corrosion, with an emphasis on critical industrial environments such as the maritime, petrochemical, energy, and infrastructure sectors. Additionally, the main classes of biosurfactants are discussed, along with their key physical and chemical characteristics, including critical micelle concentration, thermal and saline stability, adsorption capacity, and their mechanisms of action in mitigating corrosion. Finally, the article summarizes the advances of the last decade, highlighting experimental studies, emerging applications, and technological trends that consolidate biosurfactants as viable, efficient, and environmentally safe alternatives for industrial corrosion protection.

Petroleum-derived hydrophobic pollutants represent a persistent environmental concern, highlighting the need for sustainable and efficient remediation technologies. In this study, a biosurfactant produced by the yeast Starmerella bombicola ATCC 22214 using glucose and glycerol as carbon sources was characterized and evaluated for the removal of hydrophobic contaminants from different surfaces. Ionic-charge analysis indicated an anionic biosurfactant, while FTIR and ¹H/¹³C NMR analyses revealed spectral characteristics consistent with sophorolipid-type glycolipids, including a polar carbohydrate moiety associated with sophorose, ester and carbonyl functionalities, and long fatty-acid-derived aliphatic chains. The biosurfactant maintained its surface activity during 120 days of storage under different preservation conditions, with surface tension values remaining at approximately 32 ± 2 mN/m. In the Allium cepa assay, no visible cytogenetic alterations were observed at concentrations of 0.2, 0.4, and 0.8 g/L. The biosurfactant showed maximum apparent removal values, calculated relative to the nominal oil mass applied, of up to 86.61% for used engine oil on porous rocks and 77.90% for OCB1 heavy oil on metal surfaces, while 84.00% removal was obtained for burnt engine oil from cotton fabric. These findings indicate that the biosurfactant produced by S. bombicola ATCC 22214 presents structural features consistent with a sophorolipid-type glycolipid, prolonged surface activity, no visible cytogenetic alterations under the conditions of the preliminary qualitative screening, and promising performance for the removal of petroleum-derived hydrophobic contaminants from different surfaces.