Lactic acid fermentation by cells of Lactobacillus
rhamnosus immobilized
in polyacrylamide gel |
| |
Authors: | Kaloyan K Petrov Dragomir S Yankov Venko N Beschkov |
| |
Institution: | (1) Institute of Chemical Engineering, Bulgarian Academy of Sciences, 103, Acad. G. Bontchev, 1113 Sofia, Bulgaria |
| |
Abstract: | Summary The process of lactic acid fermentation of lactose to lactic acid by Lactobacillus rhamnosus ATCC 7469 has been studied. The following processes have been explored: growth kinetics, as well as lactose utilization,
production of lactic acid and further degradation of lactic acid. The immobilization experiments were conducted with microbial
cells entrapped in polyacrylamide gels. Gels with different ratios of the monomer (acrylamide) and the cross-linking agent
(N,N′-methylene-bis-acrylamide) have been tested. These were used in a repeat-batch process. The current processes inside and
outside the gel particles were subjects of examination. The evolution of the activity of immobilized cells with repeated use
showed that the particles served mainly as a donor of cells for the free culture. In all experiments a very high degree of
conversion, 85–90% was observed. After several runs however, the particles were exhausted for microbial cells. A kinetic model
of the process of lactic acid production was developed. This model allowed the evaluation of the effect of microbial growth
and diffusion limitations inside the gel particles on the process rate and the separate contribution of the free and immobilized
cells to the overall fermentation process upon multiple use. |
| |
Keywords: | Immobilization lactic acid Lactobacillus rhamnosus mathematical modeling polyacrylamide |
本文献已被 SpringerLink 等数据库收录! |
|