Homogenization of Streptococcus for Enzymatic Activity Measurements
Instrument: Precellys® 24 with Cryolys
Sample: Concentrated Streptococcus thermophilus cells
Protocol:
- Add concentrated S. thermophilus cells to the 2 ml tough microorganism lysing kit.
- Add 50 mM tris/HCl buffer, pH7*
- Run the Precellys at 6800 rpm for 3 x 30 sec with 30 sec breaks.
- Centrifuge at 15,000 x g for 10 minutes at 4°C.
In this instance, the user was looking to assess enzymatic activity. You may substitute another buffer which is appropriate for your application.
Results:
Protein content was measured within the total cell extract by Bradford assay. Enzyme activities (β-galactosidase and lactate dehydrogenase) were measured spectrophotometrically.
β-galactosidase (a) and lactate dehydrogenase (b) activities of S. thermophilus wild-type cells (white bars) and A19(Δppc;ΔcarB) mutant cells (grey bars) grown in enriched CO2 or N2 atmosphere.
