The dynamics of intracellular amino acid pools were determined in batch cultures of Saccharomyces cerevisiae. Immediate termination of metabolic activity was found to be necessary for accurate quantification of in vivo concentrations of intracellular amino acids, due to significant changes in most intracellular amino acid pools observed during extraction without an instantaneous stop of the metabolism. The method applied to batch-cultures of S. cerevisiae on glucose revealed complex dynamics in intracellular amino acid pools. The most drastic changes were observed during the diauxic shift and at the entry into the stationary phase. Even during phases of exponential growth on glucose and ethanol, cells showed significant variations in intracellular amino acid concentrations. The method presented can be used to investigate the physiology of yeast cultures, including industrially relevant batch and fed-batch processes.

A new type of continuum manipulator is presented, in which the body of the device is made up of identical, repeated interlocking fibers. A working prototype is demonstrated. Basic models describing the kinematics and mechanical properties of the device are developed, and their predictions are compared with the performance of the physical prototype. Advantages of the interlocking design include improved strength due to better load distribution, controllable stiffness, and a large open lumen.

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