Samples of algal suspension (3 mL) were collected daily from
the bioreactor tubes to be harvested and filtered with Whatman
GF/C filters to monitor N consumption rates. Solution N concentration
was measured on a Lachat QuikChem 8500 Automated Ion
Analyzer using the total N, in-line persulfate digestion, imidazole
buffer method that is available from the manufacturer (Lachat
Instruments, Loveland, CO). Total C and N in algae were measured
by a Perkin-Elmer Model 2400 CHN analyzer (Waltham, MA).