Development of New Methods in Fast Sampling and in Sample Processing for Microbial Metabolomics
A rapid sampling and the following sample processing are critical for a reliable metabolomic analysis. Due to the complicated procedure and the high quantity of parameters there are many possibilities for variations and errors. The effective and sufficient separation of the exo- and endometabolome is a specific challenge in this context. Our aim is to develop new technologies and methods to minimize the errors and to design new experiments to investigate and describe cellular metabolism and its regulation. A new fully automated rapid sampling unit with on-chip filtration has been successfully developed which greatly improves the accuracy of intracellular metabolites, especially to overcome the problem of metabolic leakage. The concept combines flexibility and accuracy. The rapid sampling unit is based on a modular system. A specific valve system assures definite sample volumes and efficient mixing of the sample with the quenching solution. A special on-line and fast filtration system was implemented which can handle high cell density culture (up to OD value near 100). This is the first fast sampling system which can work under such extrem conditions more relevant to industrial bioprocesses. The system has been use to study different metabolic regulation in microorganisms such as E. coli and Corynebacterium glutamicum.