Starch productivity in cyclically operated photobioreactors with marine microalgae—effect of ammonium addition regime and volume exchange ratio

Abstract

Large-scale production of microalgal storage compounds will likely involve marine microalgae. Previously, we described a method to enrich microalgae with a high storage compound productivity from a natural inoculum. Here, this strategy was implemented under marine conditions in a sequencing batch reactor. The influence of the volume exchange ratio and the moment of ammonium addition in the day-night cycle on the storage compound productivity are described. Storage compound productivity was maximal if ammonium was supplied at the start of the dark period rather than the light period, irrespective of the volume exchange ratio. Increasing the volume exchange ratio from 33 to 50 % per cycle induced a decrease in storage compound production if ammonium was supplied in the light whereas the storage compound productivity was comparable when ammonium was supplied in the dark. The latter indicates a shift of cell division processes to the light period at increasing volume exchange ratio, although ammonium uptake completely occurred in the dark period.

Microalgae production in a biofilm photobioreactor

“…Therefore, the productivity of the simulated suspension diminished while the biofilm productivity appeared to be unaffected by the dark zone. This simulation thus confirmed previous conclusions that dark zones should be prevented in microalgal suspension cultures (de Mooij et al 2014;Takache et al 2012).…”

“…The reported a x were weighted to the light source used for cultivation by Zijffers et al and, therefore, were recalculated to the non-weighted a x . The a x for C. reinhardtii is based on five studies (de Mooij et al 2014;Fouchard et al 2009;Takache et al 2012;Vejrazka et al 2011;Vejrazka et al 2012). An overview of the a x found in literature is depicted in (Dubinsky et al 1986).…”

“…However, it should be noted that, for suspension cultivation, optimal yields are typically obtained by preventing dark zones in the reactor (de Mooij et al 2014;Takache et al 2012). Therefore, a 7-day batch cultivation is not the most optimal cultivation strategy for suspension cultivation.…”

Hydraulic retention time effects on wastewater nutrient removal and bioproduct production via rotating algal biofilm reactor

“…Harvested biofilms in fed-batch mode as same as biomass growth analysis, were dried at 103 o C then, prepared for lipid determination procedure via colorimetric method the same as described by Mishra et al (Mishra et al, 2014) and starch determination using modified methods (Asada et al, 2012;Mooij et al, 2014 …”

Effective role of medium supplementation in microalgal lipid accumulation

“…Lipid was extracted following the lipid extraction protocol described by Mooij, de Graaff, van Loosdrecht, and Kleerebezem (). Myristic, palmitic, palmitoleic, stearic, oleic, linoleic, and linolenic acid were used as standards.…”