Team:ShanghaiFLS China/Experiments
i. The following data were acquired after 108 h 50 mL YNM (1.34% yeast nitrogenous base with 0.5% methanol, 50 µg/mL histidine and 40 µg/mL biotin) incubation, sampled every 12 h. The starting concentration was 1 OD600.
ii. 0.5% Methanol was added to the media every 24 hours to maintain the methanol concentration.
iii. A short-term methanol induction experiment was performed after the 108 h incubation to characterize the instant response to methanol induction after the yeast cells are accustomed to methanol media, hence indicating the overall induction activity of the construct. The yeast cells were collected, rinsed and stored at 4 ˚C overnight to allow GFP to fully degrade. The strains were then incubated in higher-concentration 50 mL YNM media (1.34% yeast nitrogenous base with 0.75% methanol, 50 µg/mL histidine and 40 µg/mL biotin) for 12 hours and sampled every 2 hours. The starting concentration was 3 OD600.
iv. For each experimental construct, two identical strains were created (labeled 1 and 2) and three parallels were performed for each strain.
v. A Biotek Synergy 2 plate reader was used to measure the GFP mean fluorescence intensities and the OD600 absorbance of our samples.
vi. Methanol concentration measurements were performed with a Shenzhen Sieman M100 Biosensors Analyzer.
vii. OD600 is used as an indicator of yeast concentration in the experiment.
viii. Measured unit cell GFP production is the ratio of the GFP mean fluorescence intensities to the OD600 absorbance measured by the plate reader. It shall serve as an indicator of the expression level of GFP at the sampled time point.
ix. Aggregate unit cell GFP production is the calculated total unit cell GFP fluorescence intensity. It accounts for the GFP that has degraded over the incubation period to more accurately reflect the aggregate production rate.
x. Total GFP production is the product of the yeast concentration and the aggregate unit cell GFP. It reflects the total GFP production of the reaction system of the strain.
xi. Total GFP production per gram methanol is the ratio of the total GFP production to the total methanol consumption. It reflects the overall conversion rate of methanol to the product.