Cultivation of Haematococcus pluvialis for astaxanthin production on angled bench-scale and large-scale biofilm-based photobioreactors

Abstract

The green microalga, Haematococcus pluvialis, is currently cultivated for natural astaxanthin in suspended systems. Immobilised cultivation in a twin-layer (TL) porous substrate bioreactor is a potential revolution in microalgal biotechnology worldwide. For the first time in Vietnam, small-scale (0.05 m2) and large-scale (2 m2) biofilm-based photobioreactor systems arranged at an angle of 150 were successfully designed, assembled, and operated; the temperature, humidity, air, and light conditions for H. pluvialiscultivation were successfully controlled. Studies were conducted of both systems to determine theoptimal storage time of algae after harvest from suspension before inoculation into the TL system, carbon dioxide supply method, light intensity, and initial cell density. In the 0.05 m2 and 2 m2 systems, dry biomass productivity reached 12 g m-2 d-1 (3% astaxanthin content in the dry biomass) and 11.25 g m-2 d-1 (2.8% astaxanthin) after 10 days of cultivation. The 2 m2biofilm-based photobioreactor system provides many advantages in scaling up astaxanthin production from H. pluvialis.

Biomass and Astaxanthin Productivities of Haematococcus pluvialis in an Angled Twin-Layer Porous Substrate Photobioreactor: Effect of Inoculum Density and Storage Time

“…The experiments were carried out on small scale (0.1 × 0.5 = 0.05 m 2 growth area) and large scale (0.5 m 2 × 4 growth area) angled TL-PSBRs [24]. The non-sterile culture medium was stored in 40 L plastic chambers.…”

“…Furthermore, harvesting the biomass is technically less complicated in low-angled TL-systems compared to vertical systems [16]. In Vietnam, the angled Twin-Layer photobioreactor system for immobilized cultivation of microalgae provides significant advantages over traditional suspended cultivation such as saving of water, energy and cultivation time [24]. This study investigates several factors affecting biomass and astaxanthin accumulation of H. pluvialis cultivated in a small-scale angled TL-PSBR: initial biomass (inoculum) density, algae storage time before immobilization and influence of different light intensities.…”

Biofilm cultivation of marine dinoflagellates under different temperatures and nitrogen regimes enhances DHA productivity

“…It should be noted that no external addition of CO 2 was used in this study; addition of 2% CO 2 has recently been shown to enhance biomass productivity in S. voratum CCAC 0047 (Langenbach and Melkonian 2019). Moreover, pilot-scale TL-PSBRs have been successfully developed and tested in Germany (Naumann et al 2013;Schultze et al 2015), Vietnam Tran et al 2019), China and Spain (unpubl. data) and are currently considered for scale-up.…”

Technological innovations in the cultivation of Haematococcus pluvialis microalgae: review

“…A temperatura, irradiação, concentração de nitrato e fosfato, pH e da interação desses fatores, são responsáveis por diferenças significativas no crescimento da microalga H. pluvialis (Borowitzka et al, 1991;Boussiba, 2000;García-Malea et al, 2006;Orosa et al, 2005;Tran et al, 2019).…”

“…Essa demanda deve-se ao carbono estar presente em todas as moléculas orgânicas produzidas, tais como as proteínas, carboidratos, ácidos nucléicos, lipídios e outras. Culturas de microalgas podem tornar-se limitadas em carbono, mesmo em baixa densidade celular (Lombardi;Maldonado, 2011;Tran et al, 2019) e, dependendo da velocidade de crescimento, haverá rápido consumo do carbono disponível com elevação do pH da cultura para valores superiores a pH 9.0 em sistemas não tamponados (Lourenço, 2006;Santos, 2015).…”