Production, formulation and cost estimation of a commercial biosurfactant.

Due to their amphipathic nature, biosurfactants are multifunctional molecules that have considerable potential in several industries, especially the petroleum industry. In this study, the commercial production of a biosurfactant from Pseudomonas cepacia CCT6659 grown on industrial waste was investigated in a semi-industrial 50-L bioreactor for use in the removal of hydrocarbons from oily effluents. A concentration of 40.5 g/L was achieved in the scale up and the surface tension was reduced to 29 mN/m. The biosurfactant was formulated with an added preservative, tyndallization and the combination of fluent vaporization plus the preservative. Formulated biosurfactant samples were stored for 120 days. Tensioactive properties and stability were evaluated with different pH values, temperatures and salt concentrations. The commercial biosurfactant obtained with all formulation methods demonstrated good stability, with tolerance to a wide range of pH values as well as high temperature and high salinity, enabling application in extreme environmental conditions, as it occurs in industrial plants. The biosurfactant proved to be economically viable for large-scale application, as demonstrated by the cost of the product, estimated at around US$ 0.14-0.15/L and US$ 0.02/g for the formulated and the isolated biosurfactant, respectively. Both products were applied in an oil-fired thermoelectric plant for the treatment of oily effluents and removed up to 100% of the oil. Therefore, this biosurfactant is suitable for application under extreme conditions, such as in the petroleum industry, and can be produced at a more attractive price compared to other commercially available products on the market.

Formulation and application of a biosurfactant from Bacillus methylotrophicus as collector in the flotation of oily water in industrial environment.

The present study describes the formulation of a biosurfactant produced by Bacillus methylotrophicus UCP1616 and investigates its long-term stability for application as a collector in a bench-scale dissolved air flotation (DAF) prototype. For formulation, the conservative potassium sorbate was added to the biosurfactant with or without prior heat treatment at 80 °C for 30 min. After formulation, the biosurfactant samples were stored at room temperature for 180 days and the tensioactive properties of the biomolecule were determined with different pH values, temperatures and concentrations of salt. Then, a central composite rotatable design was used to evaluate the influence of the independent variables (effluent flow rate and formulated biosurfactant flow rate) on the oil removal efficiency in the DAF prototype. The formulated biosurfactant demonstrated good stability in both conservation methods, with tolerance to a wide pH range, salinity and high temperatures, enabling its use in environments with extreme conditions. The efficiency of the formulated biomolecule through heating and addition of sorbate was demonstrated by the 92% oil removal rate in the DAF prototype. The findings demonstrate that the biosurfactant from Bacillus methylotrophicus enhances the efficiency of the DAF process, making this technology cleaner. This biosurfactant can assist in the mitigation and management of industrial effluents, contributing toward a reduction in environmental pollution caused by petroleum-based hydrocarbons.

Microbial biosurfactants as additives for food industries.

Microbial biosurfactants with high ability to reduce surface and interfacial surface tension and conferring important properties such as emulsification, detergency, solubilization, lubrication and phase dispersion have a wide range of potential applications in many industries. Significant interest in these compounds has been demonstrated by environmental, bioremediation, oil, petroleum, food, beverage, cosmetic and pharmaceutical industries attracted by their low toxicity, biodegradability and sustainable production technologies. Despite having significant potentials associated with emulsion formation, stabilization, antiadhesive and antimicrobial activities, significantly less output and applications have been reported in food industry. This has been exacerbated by uneconomical or uncompetitive costing issues for their production when compared to plant or chemical counterparts. In this review, biosurfactants properties, present uses and potential future applications as food additives acting as thickening, emulsifying, dispersing or stabilising agents in addition to the use of sustainable economic processes utilising agro-industrial wastes as alternative substrates for their production are discussed.

Assessment of toxicity of a biosurfactant from Candida sphaerica UCP 0995 cultivated with industrial residues in a bioreactor

Background: The aim of the present study was to propose a low-cost method for the production of a biosurfactant by the yeast Candida sphaerica and assess its toxicity and phytotoxicity. The medium was formulated with distilled water supplemented with residue from a soy oil refinery (5%) and corn steep liquor (2.5%) as substrates. These two products were the sources of carbon and nitrogen as well as mineral elements to encourage the growth of the microorganism and production of a biosurfactant. Results: The isolated biosurfactant yield was 6.364 g/l. The biosurfactant exhibited an excellent ability to reduce surface tension (26 mN/m) and demonstrated no toxicity against seeds of Brassica oleracea, Chicoria intybus and Solanum gilo or the micro crustacean Artemia salina employed as a bioindicator. The biosurfactant exhibited no antimicrobial activity against the fungi and bacteria tested. Conclusions: The promising results obtained in this study indicate the feasibility of producing biosurfactants from powerful non-toxic organic residues and their application in the bioremediation of contaminated soil and water.