Sunday, April 29, 2007
1B-57

The effect of age, inoculum concentration and oxygenation on the production of biosurfactants and protein-related virulence factors by Pseudomonas aeruginosa PA1

Luiz Fernando D. Tavares1, Ana Carolina L. B. Fernandes2, Frederico A. Kronemberger Sr.3, Rodrigo S. Reis1, Valéria F. Soares1, Cristiano P. Borges3, Lídia M. Santa Anna4, and Denise M. G. Freire5. (1) Chemical Institute, IQ / UFRJ, Av. Athos da Silveira Ramos,149 - Centro de Tecnologia - Bloco A, Sala 549-2, CEP: 21941-909 - Cidade Universitária / Ilha do Fundão, Rio de Janeiro, Brazil, (2) Chemical Institute, IQ/ UFRJ, Av. Athos da Silveira Ramos,149 - Centro de Tecnologia - Bloco A, Sala 549-2, CEP: 21941-909 - Cidade Universitária / Ilha do Fundão, Rio de Janeiro, Brazil, (3) Chemical Engineering Program, COPPE / UFRJ, Av. Horácio Macedo, 2030 - Centro de Tecnologia - Bloco G - Sala G-115, CEP: 21941-914, Caixa postal 68502 - Cidade Universitária / Ilha do Fundão, Rio de Janeiro, Brazil, (4) Petrobras Research Center (CENPES), Petrobras, (5) Instituto de Química, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos 149, Centro de Tecnologia, bloco A, sala 549-1 - Cidade Universitária, Rio de Janeiro, Brazil

Pseudomonas aeruginosa is a opportunistic microorganism that is able to produce biosurfactant and  protein-related virulence factors. The physiological response of this bacteria towards cell growth, biosurfactant production and protein-related virulence factors upon variable inoculum physiological age (20 and 40 hours), inoculum concentration (0.3g/L, 0.6 g/L, 1.1 g/L, 2.2 g/L, 4,5 g/L and 9,0 g/L) and media oxygenation were evaluated in this work. The results obtained showed that the inocula with a greater physiological age and the fermentation conducted with high oxygenation lead to better results in terms of biosurfactant production. On the other hand fermentation time course of elastase and non-specifics proteases showed different patterns. Under all conditions, nitrogen was the limiting substrate, and a fall in the virulence factors was noted when inocula with a greater physiological age were used. For higher inoculum concentrations (4.5 and 9 g/L) the kinetic profiles indicating cell death and rhaminolipids consumption, probably associated to a lack of nutrients in the culture. In conclusion, the results hereby presented indicated that inocullum (age and concentration) and medium aeration are very important factors that affect the ratio between biosurfactant production and protein-related virulence factors.

See more of Poster session 1
See more of General Submissions

See more of The 29th Symposium on Biotechnology for Fuels and Chemicals (April 29 - May 2, 2007)