Influence of phosphate on rhamnose-containing exopolysaccharide rheology and production by Klebsiella I-714.
Physiological conditions enhancing rhamnose-containing polysaccharide synthesis by Klebsiella I-714 were studied in batch culture (0.3-l and 2-l bioreactors). The four carbon sources tested, sucrose, sorbitol, Neosorb and Cerelose, allowed exopolysaccharide production. Larger amounts of polymer were produced when high carbon/nitrogen ratios and complex nitrogen sources were used. Exopolysaccharide synthesis was greatest at 30 degrees C, which was a suboptimal growth temperature. A reduction in the phosphate content of the medium enhanced rhamnose-containing polysaccharide production. When the initial carbon source concentration was augmented, byproducts other than exopolysaccharide were formed. Rhamnose-containing polysaccharide rheology can be modulated by changing the phosphate content of the medium.
Farrés
J
J
Departament d'Enginyeria Química, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Caminal
G
G
López-Santín
J
J
D019149:Bioreactors; D002021:Buffers; D002244:Carbon / Q000378:metabolism; D003470:Culture Media / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism / Q000494:pharmacology; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000737:chemistry; D012210:Rhamnose / Q000032:analysis*; D012212:Rheology; D013012:Sorbitol / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism
D002021:Buffers; D003470:Culture Media; D010710:Phosphates; D011135:Polysaccharides, Bacterial; D013012:Sorbitol; D013395:Sucrose; D002244:Carbon; D005947:Glucose; D009584:Nitrogen; D012210:Rhamnose