Assessment of different systems for the production of aldonic acids and sorbitol by calcium alginate-immobilized Zymomonas mobilis cells

• Published in: Bioprocess and biosystems engineering Vol. 41; no. 2; pp. 185 - 194
• Main Authors: Folle, Analia Borges, Baschera, Victoria Maria, Vivan, Luiza Tessaro, Carra, Sabrina, Polidoro, Tomás Augusto, Malvessi, Eloane, da Silveira, Mauricio Moura
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-02-2018; Springer Nature B.V
• Subjects: Alginates - chemistry; Alginic acid; Bacteria; Batch culture; Bioconversion; Bioreactors; Biotechnology; Calcium; Calcium alginate; Carbohydrates; Cells, Immobilized - metabolism; Cetyltrimethylammonium bromide; Chemistry; Chemistry and Materials Science; Environmental Engineering/Biotechnology; Food Science; Fructose; Glucuronic Acid - chemistry; Glutaraldehyde; Hexuronic Acids - chemistry; Immobilization; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; Lactose; Metabolism; Oxidoreductase; Periplasm; Reactors; Research Paper; Sorbitol; Sorbitol - metabolism; Zymomonas; Zymomonas - metabolism; Zymomonas mobilis; Sorbitol; Reactors; Glucose–fructose oxidoreductase; Operation modes; Glucono-δ-lactonase; Lactobionic acid
• ISSN: 1615-7591; 1615-7605
• DOI: 10.1007/s00449-017-1856-1

Equimolar amounts of lactobionic acid and sorbitol may be obtained in a reaction catalyzed by the enzymes glucose–fructose oxidoreductase and glucono-δ-lactonase, which are found in the periplasm of
Zymomonas mobilis
. These reactions are generally conducted using immobilized bacterial cells, and the cell treatment and immobilization steps are costly and time-consuming. This study evaluated alternatives to simplify the preparation of calcium alginate-immobilized biocatalyst and its application in different operation modes and types of reactors. It was possible to eliminate cell permeabilization with cetyltrimethylammonium bromide, and the reticulation of
Z. mobilis
cells with glutaraldehyde sufficed to inhibit the fermentative metabolism of carbohydrates by the bacterium, with accumulation of bioconversion products. When the process was carried out in a mechanically stirred reactor in batch mode, 530 mmol L
− 1
of products were obtained in 24 h. The process was also tested in fed-batch mode so as to use of a larger amount of lactose, since it could not be used in the batch because of its low solubility in water. Under this condition, final products concentration reached 745 mmol L
− 1
within 42 h. Similar results were obtained for reactions conducted in a pneumatically stirred reactor in batch and fed-batch modes, proving the potential use of this process in several industrial settings.