Abstract

PRODUCTION AND EXTRACTION OF A POTENTIAL BIOSURFACTANT BY BACILLUS ATROPHAEUS ATCC 9372 CULTIVATED IN DAIRY RESIDUES

Luiz Carlos Martins das Neves*, Larissa Salles de Freitas Lourencini, Giovanna Rossi Malaquias da Silva, Alípio de Oliveira Carmo, Marina Ishii and Inês Conceição Roberto

ABSTRACT

Biosurfactants with tensoactive and emulsifying properties have been enhancing the potential application in formulations used in several purposes as well as to cosmetics, vaccines, pharmaceuticals, food and even veterinary products. Nevertheless, the high cost of production and purification has been a limitation to the application of biosurfactants. The cost reduction can be obtained using industrial residues once it is capable to provide the nutrients necessary and sufficient for high productivity of the biotechnological product. Dairy residues are a byproduct rich in proteins, vitamins, fat, lactose and salts, containing, therefore, essential nutrients for cellular growth. Experiments were performed to obtain the ideal lactose concentration of dairy residue culture medium for the best production of the biosurfactant from Bacillus atrophaeus ATCC9372. Results indicated that the presence of lower lactose concentration (2.5 g.L-1) improved the cell and biosurfactant productivity (Px and PB), respectively, 0.092 gX.L-1.h-1and 4.67 mgB.L-1.h-1. Also, the extraction utilizing ammonium sulfate 5.0 M and t-butanol results in a biosurfactant thin layer that can be re-suspended in a buffer and presents good emulsifying activity and stability at moderate pH and temperature.

Keywords: Bacillus atrophaeus ATCC9372, biosurfactant, whey permeate, emulsifying activity.