Aerobic batch cultivation in micro bioreactor with integrated electrochemical sensor array.

Aerobic batch cultivations of Candida utilis were carried out in two micro bioreactors with a working volume of 100 muL operated in parallel. The dimensions of the micro bioreactors were similar as the wells in a 96-well microtiter plate, to preserve compatibility with the current high-throughput cultivation systems. Each micro bioreactor was equipped with an electrochemical sensor array for the online measurement of temperature, pH, dissolved oxygen, and viable biomass concentration.

Quantitative determination of glucose transfer between concurrent laminar water streams in a H-shaped microchannel.

To explore the applicability of a laminar fluid diffusion interface (LFDI) for the controlled feeding of microbioreactors, glucose diffusion experiments were carried out in a rounded H-shaped microstructure etched in a glass substrate. The diffusion channel of the microstructure had a length of 4 mm and a depth of 50 microm with a trapezoidal cross section with a width of 100 microm at the bottom and 200 microm at the surface of the channel. The microchannel was operated at residence times of less than 1 s ensuring high-mass-transfer rates.

Lab-scale fermentation tests of microchip with integrated electrochemical sensors for pH, temperature, dissolved oxygen and viable biomass concentration.

This article shows the development and testing of a microchip with integrated electrochemical sensors for measurement of pH, temperature, dissolved oxygen and viable biomass concentration under yeast cultivation conditions. Measurements were done both under dynamic batch conditions as well as under prolonged continuous cultivation conditions. The response of the sensors compared well with conventional measurement techniques.