Class: BE210
Group: R1
Members: FACILITATOR Jocelyn Poruthur, TIME & TASK KEEPER, Grant Foy, SCRIBE Danielle Antalffy, PRESENTER Keyur Shah
Date: 5/11/00
Full Text

Abstract:

A comparative study on the growth of aerobic and anaerobic growth of anaerobically prepared baker’s yeast, Saccharomyces cerevisiae, at different temperatures showed no significant difference between doubling times at anaerobic and aerobic conditions at 32?C and 37?C.  The doubling time at 32?C was 234.01?5.61 min at anaerobic conditions and 247.55?6.60 min at aerobic conditions; at 37?C the doubling time was 212.56?5.46 at anaerobic conditions and 203.87?3.35 at aerobic conditions; since the values overlap within in their confidence intervals, which were 212.56±11.74  and 203.87±7.62 minutes at 37 degrees and 234.01±11.86 and 247±12.73 minutes at 32 degrees, no significant difference can be seen between aerobic and anaerobic conditions at the two specified temperatures.  However, anaerobic data taken at 25?C suggests no growth at the specified conditions due to the length of the lag time, which was 111.423±10.93 minutes the large standard error of 9.81% of the mean in the lag time and 27.1% of the mean in the doubling time.  The lag times compared at aerobic and anaerobic conditions for 32?C and 37?C do not show a significant difference, once again due to an overlap in the confidence intervals.  Also, experimental results show that anaerobic growth causes a decrease in pH over time due to alcohol production and accumulation in the PENNCELL apparatus.