LIS enabled a continuous addition of a 50% glucose solution to the shake flask culture which would not be manageable with a non-automated process (manual handling). When compared with a culture in which the same amount of glucose (3 mL) was fed at one time point, it became clear that the fed-batch process was beneficial for cell viability and the strains growth behavior. Cell lysis could be avoided and biomass levels (monitored with the Cell Growth Quantifier) were increased compared to the single shot feeding.

Besides an improved growth behaviour, the LIS facilitated fed-batch process also showed a significant increase in active protein yields. When compared with the culture in which 3 mL of 50% glucose were fed at once, the fed-batch feeding of 50% glucose to the medium augmented the final protein yield by approximately 30%. 

This underlines the importance of culture conditions on the final product yields. Implementing the preferred cultivation conditions early on (e.g., when screening for the strongest production strain in shake flasks) is therefore essential for obtaining consistent results. Only then, the conclusions drawn can be reliably transferred to larger scales, in which fed-batch procedures are the norm for many protein production processes. 

Overall, by enabling fed-batch processes in shake flasks, the LIS contributes to creating bioreactor-like conditions in shake flasks, increasing the reproducibility of results from experiments undertaken in these two systems. By using the LIS, Dr. Morabbi Heravi could characterize production strains in smaller scales, instead of having to use larger scale bioreactor systems, and by this he could save money and time during upstream processing.