Study of the interactive effect of temperature and pH on exopolysaccharide production by Enterobacter A47 using multivariate statistical analysis.
Enterobacter A47 synthesizes fucose-containing exopolysaccharides (EPS). Maximum EPS production (>7.00 g L(-1)) was obtained for temperature and pH within 25-35°C and 6.0-8.0, respectively. Under these conditions, the polymers contained over 30% fucose. Glucose, galactose, and glucuronic acid contents were about 28%, 25%, and 10%, respectively, and the total acyl groups content was about 20 wt.%. The average molecular weight (Mw) was around 4.0 × 10(6). Outside the optimal temperature and pH ranges, fucose, galactose and glucuronic acid, and the total acyl group contents were reduced, while the glucose content increased, new monomers (rhamnose and glucosamine) were detected, and the Mw increased to ≥ 1.10 × 10(7). This study revealed the ability of Enterobacter A47 to synthesize different heteropolysaccharides as a function of pH and temperature, a feature that can be exploited to obtain tailored polymer composition. Moreover, the production of high fucose content EPS was stable for wide pH and temperature ranges, which is important for the envisaged industrial development of the bioprocess.
REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
Cristiana A V
CA
Torres
Sílvia
S
Antunes
Ana Rita
AR
Ricardo
Christian
C
Grandfils
Vítor D
VD
Alves
Filomena
F
Freitas
Maria A M
MA
Reis
D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods; D003198:Computer Simulation; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D004754:Enterobacter / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D015233:Models, Statistical; D015999:Multivariate Analysis; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000302:isolation & purification; D013045:Species Specificity; D013696:Temperature
D003470:Culture Media; D011135:Polysaccharides, Bacterial; C503194:exopolysaccharide, Enterobacter amnigenus