Comparative Lysis Efficiency of Saccharomyces cerevisiae at 40 kpsi
Culture: Lyophilised Baker’s Yeast (Saccharomyces cerevisiae) was used to inoculate 200 mL sterile YMB (Yeast Mold Broth: Peptone 5 g/L, Dextrose 10 g/L, Maltose 3 g/L, Yeast Extract 3g/L) in 1 L flasks which were then incubated at 30°C with shaking at approximately 100 rpm for 24 hours.
Disruption: The resulting culture was passed in 30 mL aliquots through either a Constant Systems Ltd. ‘Z+’ 1.1 kW Continuous Flow Cell Disruptor or a Thermo Spectronic French Pressure Cell Press at
40 kpsi. The samples were weighed before and after being passed through the machines, and the time taken to process was recorded. The machines were rinsed with 30 mL deionised water between each use.
Counting: After being passed through the machines, 10 µL of lysate was mixed 1:1 with the viability stain Trypan Blue. White live cells and blue dead cells were counted using a hemocytometer. A sample of unlysed cells from the same culture was used as a control, from which the percentage partial lysis (including blue cells) and complete lysis was calculated.