Evaluation of Escherichia coli and Candida utilis as a model continuous, competitive mixed culture system

✍ Scribed by Charles F. Goochee; Randolph T. Hatch; Theodore W. Cadman

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 997 KB
• Volume: 29
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.260290408

✦ Synopsis

The yeast Candida utilis and the bacterium Escherichia coli B/r were evaluated as a candidate experimental, continous, competitive mixed culture system under ammofavored yeast dominance, while low dilution rates fa-

-(D)(SO -S ) -(ELI)(XI)/YI

nia-nitrogen limited conditions at 30°C. High dilution rates -(EL2)(X2)~YZ = 0 vored bacterial dominance. The hydrogen ion concentration was also demonstrated to be an effective manipulative variable for control of the yeast-bacterial mixed culture. Through trial-and-error manipulation of the pH for the mixed culture operating at constant dilution rate, it was possible to locate a metastable equilibrium point and to operate in the vicinity of that point for more than 24 h. The reproducible emergence of a variant E. coliwas also noted in this study. Cambridge. MA 02140. $ Present address: Chemical Engineering Program. University of rate less than D,,, then one of the two microorganisms lution rate is operated at a value greater than Deqr the should eventually predominate. Conversely, if the di-Maryland-Baltimore County, Catonsvilk-MD 21228.

other microorganism should eventually predominate.