Strategy for waste management in the production and application of biosurfactant through surface response methodology

• Published in: Clean technologies and environmental policy 2016-03, Vol.18 (3), p.787-795
• Main Authors: dos Santos, Brunno Ferreira, Ponezi, Alexandre Nunes, Fileti, Ana Maria Frattini
• Format: Article
• Language: English
• Subjects: Bacillus subtilis; Biodiesel fuels; Carbon; Design; Earth and Environmental Science; Enhanced oil recovery; Environment; Environmental Economics; Environmental Engineering/Biotechnology; Environmental policy; Experiments; Fermentation; Glucose; Glycerol; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; Lactose; Liquor; Materials selection; Nitrates; Nitrogen; Oil recovery; Optimization; Original Paper; Policies; Potassium; Potatoes; Production increases; Solanum tuberosum; Soybean oil; Soybeans; Studies; Substrates; Sucrose; Surfactants; Sustainable Development; Toluene; Trace elements; Variance analysis; Vegetable oils; Waste management; Waste management industry; Waste materials; Wastes
• ISSN: 1618-954X; 1618-9558
• DOI: 10.1007/s10098-015-1052-4

This study aims to identify the optimal biosurfactant production process via fermentation by Bacillus subtilis , using waste material as alternative substrates (glycerin, water from potatoes processing, corn steep liquor, and frying oil), thereby highlighting the absence of synthetic substrates. A fractional factorial design 2 4−1 was previously used to determine the effects of the concentrations of the four substrates, selecting three of them to be used in a central composite rotatable design (CCRD) 2 3 . Responses of the emulsifying index after 24 h (EI 24 ) were first evaluated for fermentation in 250-mL flasks. Thus, the concentration of waste material that is able to provide EI 24 up to 100 % from 9 % of glycerin and 1 % of potato peel was determined, with subsequent experimental validation at the optimized point. One-liter-bench-batch fermentation with the optimum medium (based on the CCRD) was also carried out. In order to compare, another 1-L-bench-batch fermentation was performed using residual glycerin through the biosurfactant concentrations, dry weight, oxygen dissolved, and pH profile. Evidence of high potential for biosurfactant production (with EI 24 100 % to toluene, 67 % to hexane, and 62 % to soybean oil), which can be suitable for applications in oil recovery was presented.