15 Sustainability Metrics in the Microalgae-Based …
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15.5 Astaxanthin from Haematococcus Pluvialis
The cultivation of Haematococcus pluvialis shows lower pigment productivity
compared to Dunaliella salina. This microorganism can produce and accumulate astaxanthin up to concentrations of 1–8% per dry weight. Once the cost of
the final product also depends on productivity, the astaxanthin is produced from
Haematococcus pluvialis at a selling price of US$2,500/kg (Acién et al. 2017).
Moreover, the cultivation of Haematococcus pluvialis is more complex than
Dunaliella salina, once this microorganism does not accumulate astaxanthin under
optimal growth conditions. Thus, commercial producers, they use a two-system
strategy for astaxanthin production (Fig. 15.7b). In the growth phase, vegetative
cells are produced under optimal growth conditions for a period of 2 days. Once the
cultures of Haematococcus pluvialis are easily contaminated with other fast-growing
strains such as Scenedesmus or Chlorella, the growth phase is ideally performed in
a batch mode using tubular photobioreactors to avoid external contamination. The
carotenogenesis phase is performed for a period of 5–10 days, being induced under
nutrient deprivation conditions and high irradiance in raceway ponds (Olaizola and
Huntley 2003; Acién et al. 2014).
The two-system strategy is successfully used to commercially produce Haematococcus in the large-scale (Cezare-Gomes et al. 2019). Notoriously, some parameters
require optimization for an optimal economic and environmental performance front
these production systems. Thus, by the way, this adopts strategies for the improvement of the production process such as the use of deep ocean water at 14 °C to cool
culture systems using heat exchangers, besides sedimentation for the harvesting of
the haematocysts (Lorenz and Cysewski 2000).
Over 95% of the astaxanthin available on the market is produced synthetically, whereas astaxanthin from Haematococcus comprises <5% of the commercial products (Hu 2019). This is reflex of the relatively lower production costs
of synthetic astaxanthin (US$1,000/kg) compared to astaxanthin produced naturally (US$2,500/kg). However, the synthetic astaxanthin is not allowed in human
consumption or other human-related applications, making biologically produced
astaxanthin the preferred option in these specific markets (Acién et al. 2017).
15.6 Phycocyanin from Arthrospira Platensis
Phycocyanin is the subunit most commonly used among phycobiliproteins (Kannaujiya et al. 2019). It is the blue pigment extracted from Arthrospira platensis that in
2013 became the first natural blue food coloring to be approved by the FDA. Since
then, demand for phycocyanin has increased drastically, particularly in the Americas
and Europe, which have seen a rapid shift in consumer demand toward natural food
colorings (Buchweitz 2016).
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15.5 Astaxanthin from Haematococcus Pluvialis
The cultivation of Haematococcus pluvialis shows lower pigment productivity
compared to Dunaliella salina. This microorganism can produce and accumulate astaxanthin up to concentrations of 1–8% per dry weight. Once the cost of
the final product also depends on productivity, the astaxanthin is produced from
Haematococcus pluvialis at a selling price of US$2,500/kg (Acién et al. 2017).
Moreover, the cultivation of Haematococcus pluvialis is more complex than
Dunaliella salina, once this microorganism does not accumulate astaxanthin under
optimal growth conditions. Thus, commercial producers, they use a two-system
strategy for astaxanthin production (Fig. 15.7b). In the growth phase, vegetative
cells are produced under optimal growth conditions for a period of 2 days. Once the
cultures of Haematococcus pluvialis are easily contaminated with other fast-growing
strains such as Scenedesmus or Chlorella, the growth phase is ideally performed in
a batch mode using tubular photobioreactors to avoid external contamination. The
carotenogenesis phase is performed for a period of 5–10 days, being induced under
nutrient deprivation conditions and high irradiance in raceway ponds (Olaizola and
Huntley 2003; Acién et al. 2014).
The two-system strategy is successfully used to commercially produce Haematococcus in the large-scale (Cezare-Gomes et al. 2019). Notoriously, some parameters
require optimization for an optimal economic and environmental performance front
these production systems. Thus, by the way, this adopts strategies for the improvement of the production process such as the use of deep ocean water at 14 °C to cool
culture systems using heat exchangers, besides sedimentation for the harvesting of
the haematocysts (Lorenz and Cysewski 2000).
Over 95% of the astaxanthin available on the market is produced synthetically, whereas astaxanthin from Haematococcus comprises <5% of the commercial products (Hu 2019). This is reflex of the relatively lower production costs
of synthetic astaxanthin (US$1,000/kg) compared to astaxanthin produced naturally (US$2,500/kg). However, the synthetic astaxanthin is not allowed in human
consumption or other human-related applications, making biologically produced
astaxanthin the preferred option in these specific markets (Acién et al. 2017).
15.6 Phycocyanin from Arthrospira Platensis
Phycocyanin is the subunit most commonly used among phycobiliproteins (Kannaujiya et al. 2019). It is the blue pigment extracted from Arthrospira platensis that in
2013 became the first natural blue food coloring to be approved by the FDA. Since
then, demand for phycocyanin has increased drastically, particularly in the Americas
and Europe, which have seen a rapid shift in consumer demand toward natural food
colorings (Buchweitz 2016).