Study of process variables and scale-up of the production of biosurfactant by Bacillus subtilis in cassava wastewater. / Estudo das variaveis de processo e ampliação de escala na produção de biossurfactante por Bacillus subtilis em manipueira.
AUTOR(ES)
Francisco Fabio Cavalcante Barros
DATA DE PUBLICAÇÃO
2007
RESUMO
The bacteria Bacillus subtilis is well known by their capacity of production surfactants lipopeptides. Among these, the most studied is surfactin, a powerfull surfactant that reduces the superficial tension of the water from 72 to 27 mN/m in concentrations less than 20_M. The application of industrial wastewaters as substrate for production of biosurfactant by Bacillus has been studied in order to reduce manufacturing costs. Manipueira is the residue from cassava industrialization process to the production of flour and starch. It has been pointed as potential culture medium for biotechnological processes, including production of biosurfactants. This work studied the productive process, the properties and the stability of biosurfactant produced by Bacillus subtilis strain LB5a in pilot scale using manipueira as substrate. The produced compounds were capable of reducing the superficial tension of the water from 72 to 27 mN/m beyond presenting critical micelar concentration of 12 mg/l. It remaing stable on temperature of 100°C during 140 minutes and 121°C during 60 minutes. It was also stabile in the range of pH from 6 to 10 and in saline concentrations (until 20%). The efficiency of the primary extration by foam collection showed good results, being perfectly applicable to the process. Moreover, the involved parameters in the preparation of the manipueira has been optimized with the objective of better using of the substrate. The results presented the optimal points of heating temperature was 95°C (maximum tested temperature), warm up time of 1 minute, the acceleration centrifugal of 17,85 G x 103 and the centrifugalization time of 14,86 minutes. The results showed that the biosurfactant produced have potential applications in several industrial sectors, beyond allowing one better exploitation of the manipueira.
ASSUNTO(S)
manipueira biosurfactants bacillus subtilis biosurfactantes cassava wastewater
