GROWTH AND COMPOSITION OF Arthrospira (Spirulina) platensis IN A TUBULAR PHOTOBIOREACTOR USING AMMONIUM NITRATE AS THE NITROGEN SOURCE IN A FED-BATCH PROCESS

Abstract

-NH 4 NO 3 simultaneously provides a readily assimilable nitrogen source (ammonia) and a reserve of nitrogen (nitrate), allowing for an increase in Arthrospira platensis biomass production while reducing the cost of the cultivation medium. In this study, a 2 2 plus star central composite experimental design combined with response surface methodology was employed to analyze the influence of light intensity (I) and the total amount of added NH 4 NO 3 (M t ) on a bench-scale tubular photobioreactor for fed-batch cultures. The maximum cell concentration (X m ), cell productivity (P X ) and biomass yield on nitrogen (Y X/N ) were evaluated, as were the protein and lipid contents. Under optimized conditions (I = 148 µmol·photons·m -2 ·s -1 and M t = 9.7 mM NH 4 NO 3 ), X m = 4710 ±34.4 mg·L -1 , P X = 478.9 ±3.8 mg·L -1 ·d -1 and Y X/N = 15.87 ±0.13 mg·mg -1 were obtained. The best conditions for protein content in the biomass (63.2%) were not the same as those that maximized cell growth (I = 180 µmol·photons·m -2 ·s -1 and M t = 22.5 mM NH 4 NO 3 ). Based on these results, it is possible to conclude that ammonium nitrate is an interesting alternate nitrogen source for the cultivation of A. platensis in a fed-batch process and could be used for other photosynthetic microorganisms.

Quantitative analysis of Spirulina platensis growth with CO2 mixed aeration

“…In contrast, the biomass amounts obtained in Chen et al [10], Cruz-Martínez et al [20], da Silva et al [6] and Xie et al [11] produced comparable to or higher than those in this study. There is no definite clue but they possibly achieved such high biomass concentrations as well as high growth rates by using small diameters of reactors, which could both provide a favorable condition for light energy distribution through the reactor.…”

“…Increased algal production attenuates light capacity, which in turn affects growth rates, making any increased production self-limiting in nature [14]. CO 2 and nutrient concentrations are also significant parameters [3,5,[7][8][12][13][14][15][16][17][18][19][20]. In particular, dissolution of CO 2 governs pH, which will eventually affect algae levels.…”

Evaluation of green microalgae isolated from central and north coast of Sao Paulo as source of oil

“…However, to produce Single Cell Protein, for example, it would worth it to evaluate the physico-chemical condition for increasing the biosynthesis of these biomolecules, mainly light intensity and nitrogen content. In this context, there are several studies showing the possibility of increasing protein content in Arthrospira platensis in different types of photobioreactor by fed-batch process (Cruz-Martínez et al, 2015); repeated fed-batch (Matsudo et al, 2009) or continuous process (Avila-Leon et al, 2012;Matsudo et al, 2012) Concerning fatty acids profile, linoleic and -linolenic acid, commonly known as -6 fatty acids, are precursors of arachidonic acid, which is important in the synthesis of eicosanoids in human body (Verlengia and Lima, 2002). These eicosanoids may play a role as mediators in processes associated to inflammation, immune system modulation, and platelet aggregation (Kus et al, 2011).…”

Microscopic and Biochemical Identification of Spirulina spp. for its Biomass Cultivation by Using Different Types of Photobioreactors at Lab and Pilot Scale

“…This study tends to be very useful in the identification and growth of Spirulina on a distinct scale. However, it also dictates the improved methods for the agronomy of Spirulina species in the lab as well as on a pilot scale by exploiting three different types of photobioreactors including tabular photobioreactors [3,8], fed-batch photobioreactors [6,12], and attached photobioreactors [15] that boost the production of Spirulina biomass by enhancing its biochemical composition (as illustrated in Table 2 & 4). Whereas, the comparison between all three methods shows that the tubular photobioreactors yield the highest biomass productivity due to effective light intensity (as shown in Figure 5).…”

“…9.5 and temperature nearly at 29° C with a continuous supply of CO2 on daily basis in tubular photobioreactors. The temperature was maintained using a thermal chamber while sodium nitrate was used as a nitrogen source resulting in better production of Spirulina in tubular photobioreactors [3,8].…”