OPTIMIZATION OF GLUCONIC ACID SYNTHESIS BY REMOVING LIMITATIONS AND INHIBITIONS

Citation
Hd. Pohland et al., OPTIMIZATION OF GLUCONIC ACID SYNTHESIS BY REMOVING LIMITATIONS AND INHIBITIONS, Acta biotechnologica, 13(3), 1993, pp. 257-268
Citations number
16
Categorie Soggetti
Biothechnology & Applied Migrobiology
Journal title
ISSN journal
01384988
Volume
13
Issue
3
Year of publication
1993
Pages
257 - 268
Database
ISI
SICI code
0138-4988(1993)13:3<257:OOGASB>2.0.ZU;2-X
Abstract
The optimization task was performed using the gluconic acid synthesis by the Acetobacter methanolicus MB 58 strain. The microorganisms were grown continuously on methanol as the growth substrate. After finishin g the growth process by the deficiency of N and P, the gluconic acid s ynthesis was started by adding glucose. The synthesis process was perf ormed continuously. The oxygen transfer rate depended on the gluconic acid concentration. During the growth process, the oxygen transfer rat e reached a value of about 13 g O2 . kg-1 . h-1 using a 30-1 glass fer menter equipped with a 6 blade stirrer and fully baffled. This rate de clined to a value of between 2 and 5 g 02 - kg-1 . h-1 in the presence of gluconic acid concentrations above 150 g gluconic acid - kg-1 medi um. The yield (g gluconic acid . g-1 glucose) depended on the gluconic acid concentration and amounted to y = 0.7 in relation to 150 g gluco nic acid - kg-1 medium and y = 0.8 in relation to 200 g - kg-1 medium, respectively. The fermenters were coupled with ultrafiltration moduls (Fa. ROMICON and Fa. SARTORIUS). The biomass concentrations amounted from 5 to 40 g dry mass kg-1 medium. The ultrafiltration modules retai ned the biomass within the fermentation system. A glucose solution (30 to 50 weight percent glucose) was continuously dosed into the ferment er. The retention time was chosen between 2 and 30 h. The gluconic aci d synthesis rate reached values of up to 32 g gluconic acid . kg-1 - h -1. Within a range of up to 250 g gluconic acid . kg-1 medium, the aci d concentration had no influence on the enzyme activity.