Combined Production of Astaxanthin and β-Carotene in a New Strain of the Microalga Bracteacoccus aggregatus BM5/15 (IPPAS C-2045) Cultivated in Photobioreactor

Carotenoids astaxanthin and β-carotene are widely used natural antioxidants. They are key components of functional food, cosmetics, drugs and animal feeding. They hold leader positions on the world carotenoid market. In current work, we characterize the new strain of the green microalga Bracteacoccus aggregatus BM5/15 and propose the method of its culturing in a bubble-column photobioreactor for simultaneous production of astaxanthin and β-carotene. Culture was monitored by light microscopy and pigment kinetics. Fatty acid profile was evaluated by tandem gas-chromatography–mass spectrometry. Pigments were obtained by the classical two-stage scheme of autotrophic cultivation. At the first, vegetative, stage biomass accumulation occurred. Maximum specific growth rate and culture productivity at this stage were 100–200 mg∙L−1∙day−1, and 0.33 day−1, respectively. At the second, inductive, stage carotenoid synthesis was promoted. Maximal carotenoid fraction in the biomass was 2.2–2.4%. Based on chromatography data, astaxanthin and β-carotene constituted 48 and 13% of total carotenoid mass, respectively. Possible pathways of astaxanthin synthesis are proposed based on carotenoid composition. Collectively, a new strain B. aggregatus BM5/15 is a potential biotechnological source of two natural antioxidants, astaxanthin and β-carotene. The results give the rise for further works on optimization of B. aggregatus cultivation on an industrial scale.

Irradiance Optimation for Growing Spirulina fusiformis: Biomass, Phycocyanin, and Protein Production

The optimization of cyanobacterium microalgae cultivation technology to provide the need for food or feedstocks has recently attracted many investigators. An optimum operation on microalgae cultivation is important to reduce the excessive workload on the aquatic environment. Therefore, this study describes how the varied irradiance (2000 lux, 4000 lux, 6000 lux, 8000 lux, and 10,000 lux) treatments on a bubble column photobioreactor system affected biomass production, phycocyanin, and protein from cyanobacterium Spirulina fusiformis. The objective of this study was to obtain the optimum irradiance for producing maximum biomass, phycocyanin, and protein simultaneously. The results demonstrated some findings those were: 1) irradiance 10,000 lux made doubling time of growth earliest (only 24 hours) while 2,000 lux doubled within five days later; 2) light response curve showed that the increase of biomass concentration was linear with the increasing of irradiance; 3) a predictive model (Response Surface Method) proof that the most optimum quantity of the biomass (0.58 ±0.035 gL-1 dry weight), chlorophyll-a (0.090 ±0.023 % dry weight), and phycocyanin (2.44 ±0.00 gL-1 dry weight) were obtained on 10,000 lux, while protein contents of 79.18±5.47 % dry weight attained on the irradiance of 6000 lux. The maximum productivity of the biomass, chlorophyll-a, phycocyanin, and protein was ~Pbiomass of 24.95 mgL-1day-1; Pchl-a of 2.25E-02 mgL-1day-1; Pphycocyanin of 1.88E-02 mgL-1day-1; and Pprotein of 17.56 mgL-1day-1. Enhancement of irradiance up to 5 folds lead to the increasing of biomass chlorophyll-a, phycocyanin, and protein productivity, attained to 1.7, 5.01, 4.13, and 2.81 folds, respectively. The irradiance had a significant influence on the production of the metabolites; therefore, the irradiance must be optimized.

An Integrated Strategy for Nutraceuticals from Haematoccus pluvialis: From Cultivation to Extraction

The aim of this study was to develop an effective integrated cultivation system for Haematococcus pluvialis as a source of bioactive compounds such as astaxanthin, lutein, proteins, and fatty acids (FAs). The Chlorophyta H. pluvialis was cultivated in a vertical bubble column photobioreactor (VBC-PBR) under batch mode, allowing switching from green to red phase for astaxanthin induction. The combined effect of light intensity and nutrients on bioactive compound formation was investigated. Results showed that growth under lower nutrients availability and light intensity led to a higher concentration of biomass. Growth under high light intensity with an appropriate concentration of nitrate, sulfate, phosphate and magnesium led to ~85% and ~58% higher production of total carotenoids and fatty acids, respectively. Under high stress conditions, ~90% nitrate and phosphate consumption were observed.