Crescimento do Bacillus pumilus em meios diversos para produção de biossurfactantes

Abstract

Biosurfactants are molecules produced by microorganisms that have a structure similar to surfactants of chemical origin. They have the ability to form globular aggregates or micelles, allowing the reduction of surface tension and the mixing of phases with distinct polarities. They exhibit emulsifying functions, making them applicable in several industrial sectors, such as the pharmaceutical, cosmetic, and food industries, as well as in the bioremediation of contaminated soils and seas. They offer advantages over synthetic surfactants, as they can be produced from renewable substrates, have low toxicity, and perform better under varying parameters such as temperature and pH. The industrial production and large-scale commercialization of biosurfactants is hindered by their high production cost, with the substrates being the main contributors to this high value. Therefore, the present study aimed to produce biosurfactants in different culture media containing substrates of regional origin, to support the growth of the bacterium Bacillus pumilus, comparing them with a commercial medium. Kinetic assays of the microorganism strain were carried out for all experiments. In the growth kinetics, it was observed that the medium containing molasses most favored cell growth when compared to the others. In the biosurfactant production analysis, the molasses medium also favored a higher production of the molecule, presenting an emulsification percentage of 58.09% after 36 hours of cultivation. The medium composed of sugarcane juice did not show the expected microbial growth and demonstrated low biosurfactant production, with an emulsification index of 45.99% after 24 hours of cultivation.