Enhanced Oil Removal by a Non-Toxic Biosurfactant Formulation

Exploring the biofilm inhibitory potential of Candida sp. UFSJ7A glycolipid on siliconized latex catheters

Biosurfactants, sustainable alternatives to petrochemical surfactants, are gaining attention for their potential in medical applications. This study focuses on producing, purifying, and characterizing a glycolipid biosurfactant from Candida sp. UFSJ7A, particularly for its application in biofilm prevention on siliconized latex catheter surfaces. The glycolipid was extracted and characterized, revealing a critical micellar concentration (CMC) of 0.98 mg/mL, indicating its efficiency at low concentrations. Its composition, confirmed through Fourier transform infrared spectroscopy (FT-IR) and thin layer chromatography (TLC), identified it as an anionic biosurfactant with a significant ionic charge of -14.8 mV. This anionic nature contributes to its biofilm prevention capabilities. The glycolipid showed a high emulsification index (E24) for toluene, gasoline, and soy oil and maintained stability under various pH and temperature conditions. Notably, its anti-adhesion activity against biofilms formed by Escherichia coli, Enterococcus faecalis, and Candida albicans was substantial. When siliconized latex catheter surfaces were preconditioned with 2 mg/mL of the glycolipid, biofilm formation was reduced by up to 97% for E. coli and C. albicans and 57% for E. faecalis. These results are particularly significant when compared to the efficacy of conventional surfactants like SDS, especially for E. coli and C. albicans. This study highlights glycolipids' potential as a biotechnological tool in reducing biofilm-associated infections on medical devices, demonstrating their promising applicability in healthcare settings.

Microbial Biosurfactant: Candida bombicola as a Potential Remediator of Environments Contaminated by Heavy Metals

Industrial interest in surfactants of microbial origin has intensified recently due to the characteristics of these compounds, such as biodegradability and reduced toxicity, and their efficiency in removing heavy metals and hydrophobic organic compounds from soils and waters. The aim of this study was to produce a biosurfactant using Candida bombicola URM 3712 in a low-cost medium containing 5.0% molasses, 3.0% corn steep liquor and 2.5% residual frying oil for 144 h at 200 rmp. Measurements of engine oil tension and emulsification were made under extreme conditions of temperature (0 °C, 5 °C, 70 °C, 100 °C and 120 °C), pH (2-12) and NaCl concentrations (2-12), demonstrating the stability of the biosurfactant. The isolated biosurfactant was characterized as an anionic molecule with the ability to reduce the surface tension of water from 72 to 29 mN/m, with a critical micellar concentration of 0.5%. The biosurfactant had no toxic effect on vegetable seeds or on Eisenia fetida as a bioindicator. Applications in the removal of heavy metals from contaminated soils under dynamic conditions demonstrated the potential of the crude and isolated biosurfactant in the removal of Fe, Zn and Pb with percentages between 70 and 88%, with the highest removal of Pb being 48%. The highest percentage of removal was obtained using the cell-free metabolic liquid, which was able to remove 48, 71 and 88% of lead, zinc and iron from the soil, respectively. Tests in packed columns also confirmed the biosurfactant's ability to remove Fe, Zn and Pb between 40 and 65%. The removal kinetics demonstrated an increasing percentage, reaching removal of 50, 70 and 85% for Pb, Zn and Fe, respectively, reaching a greater removal efficiency at the end of 24 h. The biosurfactant was also able to significantly reduce the electrical conductivity of solutions containing heavy metals. The biosurfactant produced by Candida bombicola has potential as an adjuvant in industrial processes for remediating soils and effluents polluted by inorganic contaminants.

A Biosurfactant from Candida bombicola: Its Synthesis, Characterization, and its Application as a Food Emulsions

The present study aimed to produce a biosurfactant from Candida yeast cultivated in a low-cost medium made of sugar-cane molasses (5%), frying oil waste (5%), and corn steep liquor (5%). Initially, the production at the flask-scale was investigated and then scaled up in bioreactors to 1.2, 3.0, and 50 L to simulate a real production scale. The products obtained an excellent reduction in surface tensions from 70 to 29 mN·m⁻¹ in the flask-scale, comparable to 33 mN·m⁻¹ in the 1.2-L reactor, to 31 mN·m⁻¹ in the 3-L reactor, and to 30 mN·m⁻¹ in the 50-L reactor. Regarding the yield, it was observed that the isolation by liquid-to-liquid extraction aided biosurfactant production up to 221.9 g·L⁻¹ with a critical micellar concentration of 0.5%. The isolated biosurfactant did not exhibit an inhibitory effect on the germination of vegetable seeds and presented no significant acute toxicity in assays with Artemia salina and Allium cepa. Among the different formulations of mayonnaise-like sauces, the most stable formula was observed with the addition of the biosurfactant at a concentration of 0.5% and the greatest results were associated with the guar and carboxymethyl cellulose gums. Thus, the biosurfactant from C. bombicola represents a promising alternative as a food additive in emulsions.

Effects of lipopeptide biosurfactants on clinical strains of Malassezia furfur growth and biofilm formation

Lipopeptide biosurfactants (LBs) are biological molecules with low toxicity that have aroused growing interest in the pharmaceutical industry. Their chemical structure confers antimicrobial and antibiofilm properties against different species. Despite their potential, few studies have demonstrated their capability against Malassezia spp., commensal yeasts which can cause dermatitis and serious infections. Thus, the aim of this study was to evaluate the antifungal activity of biosurfactants produced by new strains of Bacillus subtilis TIM10 and B. vallismortis TIM68 against M. furfur and their potential for removal and inhibition of yeast biofilms. Biosurfactants were classified as lipopeptides by FTIR, and their composition was characterized by ESI-Q-TOF/MS, showing ions for iturin, fengycin, and surfactin, with a greater abundance of surfactin. Through the broth microdilution method, both biosurfactants inhibited the growth of clinical M. furfur strains. Biosurfactant TIM10 showed greater capacity for growth inhibition, with no statistical difference compared to those obtained by the commercial antifungal fluconazole for M. furfur 153DR5 and 154DR8 strains. At minimal inhibitory concentrations (MIC-2), TIM10 and TIM68 were able to inhibit biofilm formation, especially TIM10, with an inhibition rate of approximately 90%. In addition, both biosurfactants were able to remove pre-formed biofilm. Both biosurfactants showed no toxicity against murine fibroblasts, even at concentrations above MIC-2. Our results show the effectiveness of LBs in controlling the growth and biofilm formation of M. furfur clinical strains and highlight the potential of these agents to compose new formulations for the treatment of these fungi.