I am going to monitor dynamic fermentation using S.cerevisiae for bioethanol production in the future. The reactor scale I will use is 500ml flasks and volume of mash will be around 200ml. I need to measure some indexes at different time points. One way is to prepare 3 replicate flasks representing each time point, then do sampling and discard flasks right away. This will not introduce oxygen and keep away from contamination.
I am thinking about other alternatives since If I follow this way, I will have at least 60 flasks to handle. Is there any other alternatives for sampling ?
DEAR Yeye Lu
THE ATTACHED CONTENT MIGHT GIVE YOU SOME HELP.
GOOD LUCK
https://www.ncbi.nlm.nih.gov/pubmed/17022660
Article Optimization of Fed-Batch Saccharomyces cerevisiae Fermentat...
Optimization of fed-batch Saccharomyces cerevisiae fermentation using dynamic flux balance models.
Hjersted JL1, Henson MA.
Author information
Abstract
We developed a dynamic flux balance model for fed-batch Saccharomyces cerevisiae fermentation that couples a detailed steady-state description of primary carbon metabolism with dynamic mass balances on key extracellular species. Model-based dynamic optimization is performed to determine fed-batch operating policies that maximize ethanol productivity and/or ethanol yield on glucose. The initial volume and glucose concentrations, the feed flow rate and dissolved oxygen concentration profiles, and the final batch time are treated as decision variables in the dynamic optimization problem. Optimal solutions are generated to analyze the tradeoff between maximal productivity and yield objectives. We find that for both cases the prediction of a microaerobic region is significant. The optimization results are sensitive to network model parameters for the growth associated maintenance and P/O ratio. The results of our computational study motivate continued development of dynamic flux balance models and further exploration of their application to productivity optimization in biochemical reactors.
1/18/18
Dear Yeye,
I don't think it is necessary to do the experiment as you have described. Assuming you don't need a large volume of sample at each time point, you can do the experiment with a single flask. At each time point, aseptically remove a sample with a sterile pipet, then return the flask to the shaker to continue the incubation. Run the analyses on the sample. If you require larger sample volumes, you can also do the experiment with 400 mL of culture fluid in a 1000 mL flask.
If you use sterile pipets and practice good sterile technique, you shouldn't have to worry about introducing contaminants. If you do the sampling in a biosafety cabinet, the possibility of contamination is reduced even further. Removing a sample at each sampling point should take
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