Miniaturized bio-sensor for environment monitoring in manned space mission

The aim of our research is to investigate about the respiratory activity (thermodynamics and kinetics) of eukaryotic cells in micro-gravity condition. Cells used for the experiment are saccharomyces cerevisiae cells (common yeast). By now yeast cells, due to their similarity to human cells, are used to detect the presence of pollution, or harmful particles on food or liquids. As well as human beings, yeast cells are sensitive to pollutant, therefore the detection of such substances is based upon a measurement of yeast state of health, in terms of metabolic activity. The most common way to measure yeast metabolic activity is by “respirometry”: measurement of oxygen concentration change over time in a solution containing yeast, glucose and the investigated substance. Yeast cells, while “breathing”, produce a decrease of oxygen concentration. The steady state value, reached few minutes after the yeast injection into the glucose solution, is an indicator of the metabolic activity. The purpose of our study is to use a miniaturized device as an environmental sensor for future manned missions. For this aim has been necessary to miniaturize a whole respirometric lab and make it fully stand alone, than compare the behavior of yeast cells in a microgravity medium to the behavior on Earth conditions. The “space laboratory” is less than 1dm^3 (600g) and contains 4 identical experiments based on biosensors. In this paper are described the chemical and engineering processes (included qualification tests) needed for a miniaturization of 600 times less.