In a previous tweet, we introduced WIGGENS's CGQ biomass online monitoring system for microbial (cell) efficacy evaluation/strain screening.
This issue describes the application of biomass monitoring in the optimization of microbial (cell) culture conditions . The medium provides environmental conditions as well as carbon sources, nitrogen sources, growth factors, etc. for the growth of microorganisms (cells). The medium is versatile, but each culture has its own specificity. On the basis of the universal medium, appropriate adjustment or component addition for the characteristics of the culture has an important positive effect on the efficient production of the target product.
The following figure shows the growth curve of Saccharomyces cerevisiae (a Saccharomyces cerevisiae) in different carbon source components using the CGQ biomass monitoring system at the Goethe University in Frankfurt, Germany .

 

Different concentrations of Glc (glucose), Gal (galactose) and Mal (amide) of three carbon sources have significant effects on the growth of Saccharomyces cerevisiae, and have significant effects on the lag phase and log phase. The concentration of each component of the carbon source is different, and the time to enter the plateau of Saccharomyces cerevisiae is even more than 6 hours. This is an important reference for reducing the time period of the lag phase for efficient industrial fermentation.
The figure below shows the growth curve of Escherichia coli (E. coli) by adding different concentrations of glycerol in M9 medium.

It can be seen from the growth curve of E. coli above that in the M9 medium, the glycerol concentration is the largest factor affecting the final growth of E. coli. Compared with 0.1% glycerol concentration, the 0.4% glycerol concentration is significantly improved in the logarithmic growth phase, and the final biomass is also more than 4 times that of the low concentration glycerol.
The following figure shows the real-time biomass monitoring by CGQ through shake flask rehydration in the culture process.

In the E. coli culture, the buffer was adjusted by the LIS shake flask rehydration system during the shake flask culture, and the pH was adjusted by the buffer. In the process of culturing Escherichia coli in LB medium, the biggest factor limiting the biomass is not the medium component, but the pH value, and the pH adjustment is continued, which can effectively increase the biomass and increase the utilization rate of the medium. .

For more CGQ biomass monitoring applications, please refer to the following documents:

[1] Tripp et al (2017): Establishing a yeast-based screening system for discovery of human GLUT5inhibitors and activators (Nature – Scientific Reports)

[2] Bruder, S. & Boles, E. (2017): Improvement of the yeast based (R)-phenylacetylcarbinol production process via reduction of by-product formation (Biochemical EngineeringJournal).

[3] Gottardi et al. (2017): De novo biosynthesis of trans -cinnamicacidderivatives in Saccharomycescerevisiae (Applied Microbiology and Biotechnology).

[4] Bracharz et al. (2017): The effects of TORC signal interference on lipogenesis in theoleaginous yeast Trichosporon oleaginosus (BMCBiotechnology).  

[5] Bruder et al. (2016): Parallelised online biomass monitoring in shake flasks efficient strain and carbon source dependent growth characterisation of Saccharomyces cerevisia (Microbial Cell Factories).