Application of immobilized cell preparation obtained from biomass of Gluconacetobacter xylinus bacteria in biotransformation of glycerol to dihydroxyacetone.
BACKGROUND
Dihydroxyacetone (DHA), being a product of glycerol oxidation by acetic acid bacteria, is an important compound widely applied in the cosmetic, food, and pharmaceutical industry, as well as in medicine. Biotransformation of glycerol to DHA is catalyzed by glycerol dehydrogenase (GlyDH, EC 1.1.1.6) bound with the cytoplasmic membrane of bacteria. An attempt was undertaken in this study to conduct glycerol biotransformation with immobilized fractions of a cell preparation with GlyDH activity. The content of dihydroxyacetone obtained with the cell preparation was compared with its content achieved in the reaction with immobilized viable cells of G. xylinus.


METHODS
Cell walls of Gluconacetobacter xylinus bacteria were disintegrated enzymatically. The resultant preparation was immobilized on calcium alginate or first separated into two fractions (precipitate and supernatant) by centrifugation and then immobilized. DHA content was determined colorimetrically after the reaction with 3,5-dinitrosalicilic acid. Glycerol content was assayed with the refractometric method.


RESULTS
After 20 days of the process, the concentration of DHA obtained with immobilized whole cells reached 25 g/l. In turn, the content of DHA obtained in the same period with immobilized fractions of the cell preparation accounted for 16.9 g/l and 8.95 g/l (depending on the fraction applied).


CONCLUSIONS
DHA may be obtained in the process independent of G. xylinus metabolic activity using a preparation which displays the catalytic activity of glycerol dehydrogenase and obtained as a result of disintegration of live bacterial cells. The application of such a preparation may in the future eliminate technological problems posed by the presence of bacterial cells and their metabolites in the culture medium.
Warsaw University of Life Sciences - SGGW, Poland.
Lidia
L
Stasiak-Różańska
Stanisław
S
Błażejak
Aleksandra
A
Miklaszewska
D000464:Alginates / Q000378:metabolism; D018533:Biomass; D001711:Biotransformation; D002384:Catalysis; D018914:Cells, Immobilized / Q000378:metabolism; D003470:Culture Media / Q000378:metabolism; D004098:Dihydroxyacetone / Q000378:metabolism*; D041822:Gluconacetobacter xylinus / Q000378:metabolism*; D020723:Glucuronic Acid / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism*; D006603:Hexuronic Acids / Q000378:metabolism; D010084:Oxidation-Reduction; D012031:Refractometry; D013401:Sugar Alcohol Dehydrogenases / Q000378:metabolism
D000464:Alginates; D003470:Culture Media; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D013401:Sugar Alcohol Dehydrogenases; C020672:glycerol dehydrogenase; D004098:Dihydroxyacetone; D005990:Glycerol