Evaluation of biosurfactant production using Bacillus subtilis with an expression vector based on the quorum sensing system

Abstract

Surfactants are amphiphilic molecules formed by hydrophilic and hydrophobic groups to reduce the surface tension between two-phase systems, having detergency, dispersion, emulsification, and biological activities. The global surfactant market has established itself strongly among the most diverse applications such as pharmaceuticals, beverages, food, cosmetics, and cleaning products, thus highlighting its importance economic. The synthesis of this compound occurs chemically and biologically from bacteria, yeasts, and fungi, which is the object of numerous studies due to its biodegradability, low toxicity, and sensitivity to extreme environments, making it advantageous to replace synthetic surfactants. Surfactin is an example of a biosurfactant belonging to the class of lipopeptides, obtained from culture media containing strains of Bacillus subtilis, providing excellent surfactant activity and numerous applications. Bacillus subtilis is a gram-positive bacterium capable of promoting cell differentiation, showing resistance to high variations in temperature and pH. Cell differentiation requires cell-to-cell communication that is a density-dependent cell called quorum sensing, and through signaling molecules such as surfactin,play significant activity in the differentiation of B. subtilis. In this way, the present project aims to study the process of production of surfactin using microorganisms based on production in the quorum sensing system, and statistical analysis of thecomposition of the culture medium and the use of oxygen vectors for the transfer of oxygen. It is expected, therefore, to obtain the biosurfactant through a culture medium optimized with high speed of oxygen transfer and with a consequent decrease of the impeller agitation frequency and the flow rate, aiming at non-foaming.