A fuzzy logic controller to control nutrient dosage in a fed-batch baker's yeast process
A fuzzy logic controller designed to control glucose feeding in a fed-batch baker's yeast process is presented. Feeding is carried out in portions and the controller determines the time at which glucose should be added and computes the size of the portion to provide the maximum glucose uptake rate. Moreover, the controller detects and prevents the occurrence of overdosage. The experimental results indicate that yield and specific growth rate obtained with the controller approached 55% and 0.13 h−1, respectively.
ARE MONOD MODELS ENOUGH FOR BIOREACTOR CONTROL? PART I – EXPERIMENTAL RESULTS
Abstract A model based substrate control system for yeast fed batch cultivations is presented. The control system consists of a FIA measurement system, which get a cell free sample stream from the culture broth due to a probing system with a time delay of 360 s. The glucose measurement values were utilized by a discrete-continuous extended Kalman filter, which applied the typical Monod model. The estimated values were applied to run a feedforward as well as feedback PI controller for set point control at 0.05 g/L glucose. The mean glucose measurement was 0.051 g/L with a standard deviation of 0.009 g/L. Therefore, the Monod model seems to be adequate for control, however the specific growth rate itself was not constant neither was the specific uptake rate of oxygen and the specific production rate of carbon dioxide constant, which indicate metabolic changes during the cultivation.
Enumeration of total coliforms, fecal coliforms, and Escherichia coli in foods by hydrophobic grid membrane filter: supplementary report.
Raw, comminuted poultry meat was used to determine the specificity of the media and incubation conditions used in the hydrophobic grid membrane filter method. Confirmation rates for target colonies were 100% for total coliforms, 98% for fecal coliforms, and 97-99% for Escherichia coli. The results of total coliform enumeration in 30 pasteurized milk samples by both the hydrophobic grid membrane filter method and AOAC method 46.013-46.016 are also reported.