The complete NANOBE system was constructed on the basis of the commonly agreed structure of the system and the functions of the individual modules developed in form of several stand-alone units: sampling; sample treatment and delivery; in-situ monitoring of pH, dissolved oxygen (dO2) and carbon dioxide (pCO2); cell counting, sorting and lysis; ELISA (enzyme linked immunosorbent assay) based protein analysis; and finally CE-MS to analyse intra- and extracellular metabolites. The planned full setup occupied an area of 2x2 m2 including the bioreactor and its peripheries. Most of the required space was occupied by auxiliary components such as pumps, valves or electrical power supplies. The virtual system control software (LabView) controlled the individual analysis and core system modules.

In the NANOBE project the primary example of the application was all along the production of organic acids in yeast Saccharomyces cerevisiae. Lactic acid production in genetically modified S. cerevisiae strain was focused on when testing the whole NANOBE system.

In total, four analysis cycles were carried out with the integrated system at the very end of the project. The monitored dissolved oxygen concentrations were in good agreement with the values measured using conventional sensor. The pH and CO2 sensors worked well. There were some issues related to the optical sensor attachment that can be easily solved in future. The sample was successfully transported from the bioreactor to the ELISA and MS modules in two cycles out of four. One out of the two successful system operation cycles resulted in successful data readout in both the ELISA and MS modules. The results from the ELISA analysis suggested that the dilution was not totally reliable. The CE-MS analysis results were qualitatively in good agreement with data from the manually-taken sample using the same Microsaic mass spectrometer.

The main achievements of the project were:

• Two new analysis tools (micro mass spectrometer already in the market and automated platform for unattended ELISA tests at industrialised prototyping level)

• New innovative methods and devices developed for dead-volume free µL-scaled sampling and sample handling. The 20 µl sample volume is most probably the smallest sample volume of which so many different analytes can be measured.

• Developed digital microfluidics for handling 1 µL droplets that push the boundaries of working with really small sample volume so that the initial sample can be separated for several analytical devices.

• Demonstration of tools for counting and sorting of dead and alive yeast cells with added cell concentration estimation. 

• New tools developed for lysis of the yeast cells.

• New optical sensor technology developed for autoclavable sensors for pH in the range of 3 to 6

• More robust optical sensors for measuring dissolved CO2

• One patent application.

• 19 scientific journal publications and 15 conference presentations.

Overall, the on-line monitoring tools developed in the NANOBE project can help to increase the production rate, yield and concentration of the final product of a fermentation process. These improvements in process monitoring may be crucial for the economic viability of a new bio-based product.