Zymomonas mobilis as catalyst for the biotechnological production of sorbitol and gluconic acid.
The conversion of glucose and fructose into gluconic acid (GA) and sorbitol (SOR) was conducted in a batch reactor with free (CTAB-treated or not) or immobilized cells of Zymomonas mobilis. High yields (more than 90%) of gluconic acid and sorbitol were attained at initial substrate concentration of 600 g/L (glucose plus fructose at 1:1 ratio), using cells with glucose-fructose-oxidoreductase activity of 75 U/L. The concentration of the products varied hyperbolically with time according to the equations (GA)=t(GA)(max)/(W(GA) +t), (SOR)=t (SOR)(max)/(W(Sor)+t), v(GA)=[W(GA) (GA)(max)]/(W(GA)+t)(2) and V(SOR)=[W(SOR) (SOR)(max)]/(W(SOR)+t)(2). Taking the test carried out with free CTAB-treated cells as an example, the constant parameters were (GA)(max)= 541 g/L, (SOR)(max)=552 g/L, W(GA)=4.8h, W(SOR)=4.9h, upsilon(GA)=112.7 g/L. and upsilon(SOR)=112.7 g/L.
Pharmacy School, University of Joinville, Santa Catarina, SC, Brazil.
Gilmar Sidney
GS
Erzinger
Michele
M
Vitolo
D019149:Bioreactors / Q000382:microbiology*; D001709:Biotechnology / Q000379:methods; D003198:Computer Simulation; D005240:Feasibility Studies; D005632:Fructose / Q000378:metabolism*; D005942:Gluconates / Q000302:isolation & purification / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D008954:Models, Biological; D010865:Pilot Projects; D013012:Sorbitol / Q000302:isolation & purification / Q000378:metabolism*; D017355:Zymomonas / Q000378:metabolism*
D005942:Gluconates; D005632:Fructose; D013012:Sorbitol; D005947:Glucose; C030691:gluconic acid