Avaliação de biossurfactantes produzidos por Bacillus sp. TIM10 em formulação de shampoo

Abstract

Surfactants are active interface agents widely used in the cosmetic industry. Most of these substances are synthesized from petroleum derivatives and are associated with environmental disturbances and human health problems. Biosurfactants are non-toxic and biodegradable natural compounds that appear as alternatives with better surface-active and emulsifying activities, able to integrate cosmetic formulations in a safer and more effective way. The objective of this work was to evaluate the control of Malassezia by biosurfactants produced by Bacillus sp. Tim10. To verify the efficiency of the preparation, emulsion tests were carried out using the autoclaved and non-autoclaved preparation and the reduction of surface tension using an automatic tensiometer. To assess the toxicity, the germination of lettuce seeds (Lactura sativa) was observed in different concentrations of the biosurfactate preparation. The pour-plate method was used to evaluate the control of Malassezia by commercial shampoos and by the preparation of biosurfactants at a concentration of 400 mg/L. Through the tests carried out, it was observed that the emulsifying activity of the autoclaved biosurfactants reached an average index of 69.33% of emulsion, and the non-autoclaved one presented 70%. As a result of the surface tension reduction test, the biosurfactant preparation showed a surface tension of 40% of the Milli-Q water that consumes a value of 28.9 mN/m. Note that the biosurfactant preparation even at the highest concentration did not inhibit lettuce (Lactura sativa) seed germination. Evaluating the commercial shampoos as Malassezia control, the growth halo of each sample in each strain was observed and the diameter was measured. The biosurfactant preparation produced by Bacillus Tim10 did not show follow-up activity on the growth of clinical Malassezia isolates. Thus, the preparation of biosurfactants presents itself as a promising surfactant capable of maintaining its emulsifying characteristic after being subjected to pressure and heat, in addition to the ability to reduce surface tension and non-toxicity in the germination of lettuce seeds (Lactura sativa).