Carbon Flux

In addition to measuring the OD730 of our Synechocystis, we also measured the dry weight in grams of the culture between the third and eighth day. We also measured the dry weight of an equal volume of BG-11 to obtain the dry weight of the Synechocystis alone. Our measurements were made by weighing 10mL of culture in pre-weighed aluminum weigh boats that had been dried for 24 hours in a 900 C oven. In order to calculate the approximate carbon flux from our data, several other plots were created.
First, we selected a linear portion of our growth curve, and fitted the curve to a line in order to determine the rate of change of OD730 per day.

Second, a graph of gDW vs OD730 and fitted to a line to determine the rate of change of gDW per OD730.

With all these data, we were able to calculate the influx of carbon into the cell, assuming that all the increase in mass of the culture was from bicarbonate. The calculations used to obtain the flux are shown below

Since the molar mass of bicarbonate is 61.017 g/mol, the influx of bicarbonate into the cell can be calculated to be: