Abstract
We have developed a direct frequency comb spectroscopy instrument, which we have tested on Saccharomyces cerevisiae (baker's yeast) by measuring its CO(2) output and production rate as we varied the environmental conditions, including the amount and type of feed sugar, the temperature, and the amount of yeast. By feeding isotopically-enhanced sugar to the yeast, we demonstrate the capability of our device to differentiate between two isotopologues of CO(2), with a concentration measurement precision of 260 ppm for (12)C(16)O(2) and 175 ppm for (13)C(16)O(2). We also demonstrate the ability of our spectrometer to measure the proportion of carbon in the feed sugar converted to CO(2), and estimate the amount incorporated into the yeast biomass.