Investigating Yeast Power Arthur Yip and Dolly Lin Sir Winston Churchill Secondary Floor Location : S 190 B

Adapted from Bennetto's system, a microbial fuel cell system was used to investigate the effects of different amounts of sugar and oxygen on the effectiveness of cellular respiration of baker's yeast. Data gathered from trials with 0.5g, 1.0g, 1.5g, and 2.0g of sugar showed that an increase in initial sugar input may have encouraged the yeast to use the anaerobic metabolic pathway, even in aerated conditions. A possible explanation is catabolic repression, the deactivation of the aerobic cellular pathway, which enables yeast to lower the excess sugar concentration by using the faster but less energy-efficient anaerobic metabolic process.

Further experimentation was performed with multiple cells connected in series and in parallel, and with varied loads, to test effective power output. Microbial fuel cell systems have great potential in its conceivable capabilities to produce electricity by digesting and processing organic material or waste.