Production of lactic acid from sucrose: strain selection, fermentation, and kinetic modeling.
Lactic acid is an important product arising from the anaerobic fermentation of sugars. It is used in the pharmaceutical, cosmetic, chemical, and food industries as well as for biodegradable polymer and green solvent production. In this work, several bacterial strains were isolated from industrial ethanol fermentation, and the most efficient strain for lactic acid production was selected. The fermentation was conducted in a batch system under anaerobic conditions for 50 h at a temperature of 34 degrees C, a pH value of 5.0, and an initial sucrose concentration of 12 g/L using diluted sugarcane molasses. Throughout the process, pulses of molasses were added in order to avoid the cell growth inhibition due to high sugar concentration as well as increased lactic acid concentrations. At the end of the fermentation, about 90% of sucrose was consumed to produce lactic acid and cells. A kinetic model has been developed to simulate the batch lactic acid fermentation results. The data obtained from the fermentation were used for determining the kinetic parameters of the model. The developed model for lactic acid production, growth cell, and sugar consumption simulates the experimental data well.
Lunelli
Betânia H
BH
Laboratory of Optimization, Design and Advanced Control, Department of Chemical Processes, School of Chemical Engineering, State University of Campinas, P.O. Box 6066, 13083-970 Campinas, São Paulo, Brazil. betania@feq.unicamp.br
Andrade
Rafael R
RR
Atala
Daniel I P
DI
Wolf Maciel
Maria Regina
MR
Maugeri Filho
Francisco
F
Maciel Filho
Rubens
R
D019149:Bioreactors / Q000382:microbiology; D005285:Fermentation; D007218:Industrial Microbiology / Q000379:methods; D019344:Lactic Acid / Q000096:biosynthesis*; D007777:Lactobacillaceae / Q000145:classification / Q000378:metabolism*; D008962:Models, Theoretical; D008965:Molasses; D013395:Sucrose / Q000378:metabolism*
D019344:Lactic Acid; D013395:Sucrose