The effect of temperature and bacterial growth phase on protein extraction by means of electroporation

• Protein extraction was achieved by electroporation.
• Temperature has a significant effect on protein extraction but not on viability.
• Lower temperatures are preferred for better protein yield.
• Bacterial growth phase has no effect on protein extraction or viability.

Different chemical and physical methods are used for extraction of proteins from bacteria, which are used in variety of fields. But on a large scale, many methods have severe drawbacks. Recently, extraction by means of electroporation showed a great potential to quickly obtain proteins from bacteria. Since many parameters are affecting the yield of extracted proteins, our aim was to investigate the effect of temperature and bacterial growth phase on the yield of extracted proteins. At the same time bacterial viability was tested. Our results showed that the temperature has a great effect on protein extraction, the best temperature post treatment being 4 °C. No effect on bacterial viability was observed for all temperatures tested. Also bacterial growth phase did not affect the yield of extracted proteins or bacterial viability. Nevertheless, further experiments may need to be performed to confirm this observation, since only one incubation temperature (4 °C) and one incubation time before and after electroporation (0.5 and 1 h) were tested for bacterial growth phase. Based on our results we conclude that temperature is a key element for bacterial membrane to stay in a permeabilized state, so more proteins flow out of bacteria into surrounding media.