Full Text - The influence of centrifugation on Zymomonas mobilis aggregation

The influence of centrifugation on Zymomonas mobilis aggregation

María de los Angeles Perez Fernandez Palha
Departamento de Engenharia Química
Universidade Federal de Pernambuco
Cidade Universitária
P.O. BOX: 50670-901
Recife, Pernambuco, Brasil
Tel : 55 81 32710095
Fax: 55 81 32710095
E-mail: angeles@ufpe.br

Carlos Edison Lopes
Departamento de Antibióticos
Universidade Federal de Pernambuco
Cidade Universitaria
P.O. Box: 50670 901
Recife, Pernambuco, Brasil
Tel: 55 81 32718346
Fax: 55 81 32718346
E-mail: celopez@ufpe.br

Maria Alice Gomes de Andrade Lima*
Departamento de Engenharia Química
Universidade Federal de Pernambuco
Cidade Universitária
P.O. BOX: 50670-901
Recife, Pernambuco, Brasil
Tel : 55 81 32710095
Fax: 55 81 32710095
E-mail: magal@ufpe.br

Nei Pereira Junior
Departamento de Engenharia Bioquímica
Escola de Quimica
Universidade Federal do Rio de Janeiro
Ilha do Fundão
P.O. Box: 21910-900
Rio de Janeiro, Brasi
Tel: 55 81 25627567
Fax: 55 81 25627567
E-mail: nei@eqfrj.brasil

* Corresponding author

Flocculent Zymomonas mobilis breaks down in smaller flocs and individual cells when centrifuged. The main consequence of it is an increase in the dispersion of the sample, suggesting that the influence of the centrifugal force on the aggregation of cells is worth to study. The experiments showed that the degree of dispersion varied between 30% and 100% when the centrifugal acceleration changed from 25 g to 2500 g. Observation under the electronic microscope showed that a slimy material covered the cells recovered by gentle gravitational settling and, that the centrifuged cells presented a bare cell wall.