scholarly journals Examination of Photo-, Mixo-, and Heterotrophic Cultivation Conditions on Haematococcus pluvialis Cyst Cell Germination

2021 ◽  
Vol 11 (16) ◽  
pp. 7201
Author(s):  
Andreas Bauer ◽  
Mirjana Minceva
Keyword(s):  
Haematococcus Pluvialis ◽  
Industrial Process ◽  
Growth Conditions ◽  
Extraction Yield ◽  
Biotechnological Production ◽  
Cyst Cell ◽  
Cell Matrix ◽  
Heterotrophic Cultivation ◽  
Cell Wall Disruption ◽  
Cyst Cells

The microalgae Haematococcus pluvialis is used for the biotechnological production of astaxanthin. The red carotenoid accumulates in the cytoplasm under unfavorable conditions. Astaxanthin synthesis is associated with the transformation of motile vegetative cells into non-motile cyst cells. In the industrial process, after harvesting, the cyst cells are mechanically disrupted, dried, and finally, astaxanthin is extracted with supercritical CO2. The germination of the cyst cells represents an interesting alternative, replacing the mechanical cyst cell wall disruption. When cyst cells are exposed to favorable growth conditions, germination of the cyst cells occurs and zoospores are released after a certain time. These zoospores show a much weaker cell matrix compared to cyst cells. In this study, germination under phototrophic, mixotrophic, and heterotrophic conditions was examined. Glucose was used as the carbon source for mixotrophic and heterotrophic germination. Applying heterotrophic conditions, up to 80% of the cells were in the zoospore stage 49 h after the start of germination, and extraction yields of up to 50% were achieved using the solvent ethyl acetate for the extraction of astaxanthin from the algal broth containing zoospores. An extraction yield of up to 64% could be achieved by doubling the nitrate concentration and combining mixotrophic and heterotrophic cultivation.

scholarly journals Techno-economic analysis of a new downstream process for the production of astaxanthin from the microalgae Haematococcus pluvialis

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Andreas Bauer ◽  
Mirjana Minceva
Keyword(s):  
Cell Wall ◽  
Economic Analysis ◽  
Ethyl Acetate ◽  
Net Present Value ◽  
Haematococcus Pluvialis ◽  
Light Stress ◽  
Downstream Process ◽  
Cell Wall Disruption ◽  
Cyst Cells ◽  
Astaxanthin Extraction

AbstractThe biotechnological production of the carotenoid astaxanthin is done with the microalgae Haematococcus pluvialis (H. pluvialis). Under nutrient deficiency and light stress, H. pluvialis accumulates astaxanthin intracellularly and forms a resistant cyst cell wall that impedes direct astaxanthin extraction. Therefore, a complex downstream process is required, including centrifugation, mechanical cell wall disruption, drying, and supercritical extraction of astaxanthin with CO2. In this work, an alternative downstream process based on the direct extraction of astaxanthin from the algal broth into ethyl acetate using a centrifugal partition extractor (CPE) was developed. A mechanical cell wall disruption or germination of the cysts was carried out to make astaxanthin accessible to the solvent. Zoospores containing astaxanthin are released when growth conditions are applied to cyst cells, from which astaxanthin can directly be extracted into ethyl acetate. Energy-intensive unit operations such as spray-drying and extraction with supercritical CO2 can be replaced by directly extracting astaxanthin into ethyl acetate. Extraction yields of 85% were reached, and 3.5 g of oleoresin could be extracted from 7.85 g homogenised H. pluvialis biomass using a CPE unit with 244 mL column volume. A techno-economic analysis was done for a hypothetical H. pluvialis production facility with an annual biomass output of 8910 kg. Four downstream scenarios were examined, comparing the novel process of astaxanthin extraction from homogenised cyst cells and germinated zoospores via CPE extraction with the conventional industrial process using in-house or supercritical CO2 extraction via an external service provider. After 10 years of operation, the highest net present value (NPV) was determined for the CPE extraction from germinated zoospores.

scholarly journals Food Ingredients and Nutraceuticals from Microalgae: Main Product Classes and Biotechnological Production

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1626
Author(s):  
Regina Kratzer ◽  
Michael Murkovic
Keyword(s):  
Growth Conditions ◽  
Food Supplement ◽  
Natural Food ◽  
Biotechnological Production ◽  
Microalgal Biomass ◽  
Food Ingredients ◽  
Fishmeal Replacement ◽  
Economic Production ◽  
Energy Inputs ◽  
Food Dyes

Microalgal products are an emerging class of food, feed, and nutraceuticals. They include dewatered or dried biomass, isolated pigments, and extracted fat. The oil, protein, and antioxidant-rich microalgal biomass is used as a feed and food supplement formulated as pastes, powders, tablets, capsules, or flakes designed for daily use. Pigments such as astaxanthin (red), lutein (yellow), chlorophyll (green), or phycocyanin (bright blue) are natural food dyes used as isolated pigments or pigment-rich biomass. Algal fat extracted from certain marine microalgae represents a vegetarian source of n-3-fatty acids (eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), γ-linolenic acid (GLA)). Gaining an overview of the production of microalgal products is a time-consuming task. Here, requirements and options of microalgae cultivation are summarized in a concise manner, including light and nutrient requirements, growth conditions, and cultivation systems. The rentability of microalgal products remains the major obstacle in industrial application. Key challenges are the high costs of commercial-scale cultivation, harvesting (and dewatering), and product quality assurance (toxin analysis). High-value food ingredients are commonly regarded as profitable despite significant capital expenditures and energy inputs. Improvements in capital and operational costs shall enable economic production of low-value food products going down to fishmeal replacement in the future economy.

scholarly journals Novel Insights into the Biotechnological Production of Haematococcus pluvialis-Derived Astaxanthin: Advances and Key Challenges to Allow Its Industrial Use as Novel Food Ingredient

2020 ◽  
Vol 8 (10) ◽  
pp. 789 ◽  
Author(s):  
Samuel Jannel ◽  
Yanis Caro ◽  
Marc Bermudes ◽  
Thomas Petit
Keyword(s):  
Haematococcus Pluvialis ◽  
Biological Activities ◽  
Biochemical Properties ◽  
Added Value ◽  
Human Consumption ◽  
Biotechnological Production ◽  
Food Ingredient ◽  
Industrial Sustainability ◽  
Natural Forms ◽  
Biotechnological Processes

Astaxanthin shows many biological activities. It has acquired a high economic potential and its current market is dominated by its synthetic form. However, due to the increase of the health and environmental concerns from consumers, natural forms are now preferred for human consumption. Haematococcus pluvialis is artificially cultured at an industrial scale to produce astaxanthin used as a dietary supplement. However, due to the high cost of its cultivation and its relatively low biomass and pigment productivities, the astaxanthin extracted from this microalga remains expensive and this has probably the consequence of slowing down its economic development in the lower added-value market such as food ingredient. In this review, we first aim to provide an overview of the chemical and biochemical properties of astaxanthin, as well as of its natural sources. We discuss its bioavailability, metabolism, and biological activities. We present a state-of-the-art of the biology and physiology of H. pluvialis, and highlight novel insights into the biotechnological processes which allow optimizing the biomass and astaxanthin productivities. We are trying to identify some lines of research that would improve the industrial sustainability and economic viability of this bio-production and to broaden the commercial potential of astaxanthin produced from H. pluvialis.

Pigment Composition of Haematococcus pluvialis Green Alga under the Action of Several Inducers of Astaxanthin Accumulation

2020 ◽  
Vol 36 (4) ◽  
pp. 29-33
Author(s):  
R.G. Goncharik ◽  
E.A. Kulikov ◽  
A.A. Selishcheva
Keyword(s):  
Sodium Chloride ◽  
High Intensity ◽  
Sodium Acetate ◽  
Haematococcus Pluvialis ◽  
Basic Research ◽  
Biotechnological Production ◽  
Fundamental Research ◽  
Simultaneous Decrease ◽  
Valuable Compounds ◽  
High Intensity Light

The content of astaxanthin, including its mono- and diesters, and photosynthetic pigments, has been analyzed in cells of H. pluvialis strain IBCE-H17 under the combined prolonged action of several inducers of astaxanthin accumulation. The effective induction of the astaxanthin accumulation, mainly in the form of monoesters of fatty acids, was shown after a 20-day cultivation under high-intensity light and with the addition of 1-2 g/l of sodium acetate to the culture medium. A simultaneous decrease in the content of chlorophylls and lutein in the H. pluvialis cells was observed under these conditions. The use of sodium acetate in combination with sodium chloride did not lead to noticeable changes in the content of astaxanthin compared with the use of sodium acetate alone. The obtained data can be helpful in the biotechnological production of Haematococcus biomass enriched with economically valuable compounds. astaxanthin, Haematococcus pluvialis, pigments, sodium acetate, sodium chloride, high-intensity light. This work was supported by Grant no. Б19РМ-010 of the Belarusian Republican Foundation for Fundamental Research and Grant no. 19-54-04003 of the Russian Foundation for Basic Research.

scholarly journals Electro-Fenton Based Technique to Enhance Cell Harvest and Lipid Extraction from Microalgae

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3813 ◽  
Author(s):  
Shuai Zhang ◽  
Yuyong Hou ◽  
Zhiyong Liu ◽  
Xiang Ji ◽  
Di Wu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Lipid Extraction ◽  
Extraction Yield ◽  
Biofuel Production ◽  
Transmission Electron ◽  
Cell Wall Disruption ◽  
Dry Cell Weight ◽  
Major Bottleneck ◽  
Wet Microalgae ◽  
Disruption Method

Currently, lipid extraction remains a major bottleneck in microalgae technology for biofuel production. In this study, an effective and easily controlled cell wall disruption method based on electro-Fenton reaction was used to enhance lipid extraction from the wet biomass of Nannochloropsis oceanica IMET1. The results showed that 1.27 mM of hydroxide radical (HO•) was generated under the optimal conditions with 9.1 mM FeSO4 in a 16.4 mA·cm−2 current density for 37.0 min. After the electro-Fenton treatment, the neutral lipid extraction yield of microalgae (~155 mg) increased from 40% to 87.5%, equal to from 12.2% to 26.7% dry cell weight (DCW). In particular, the fatty acid composition remained stable. The cell wall disruption and lipid extraction processes were displayed by the transmission electron microscope (TEM) and fluorescence microscopy (FM) observations, respectively. Meanwhile, the removal efficiency of algal cells reached 85.2% within 2 h after the reaction was terminated. Furthermore, the biomass of the microalgae cultured in the electrolysis wastewater treated with fresh nutrients reached 3 g/L, which is 12-fold higher than that of the initial after 24 days. These finds provided an economic and efficient method for lipid extraction from wet microalgae, which could be easily controlled by current magnitude regulation.

scholarly journals c-Src-Mediated Epithelial Cell Migration and Invasion Regulated by PDZ Binding Site

2007 ◽  
Vol 28 (2) ◽  
pp. 642-655 ◽  
Author(s):  
Martin Baumgartner ◽  
Gerald Radziwill ◽  
Mihaela Lorger ◽  
Andreas Weiss ◽  
Karin Moelling
Keyword(s):  
Cell Migration ◽  
Basement Membrane ◽  
Normal Growth ◽  
Growth Conditions ◽  
Regulatory Function ◽  
Migration And Invasion ◽  
Src Tyrosine Kinase ◽  
Surrounding Matrix ◽  
Cell Matrix ◽  
C Terminus

ABSTRACT c-Src tyrosine kinase controls proliferation, cell adhesion, and cell migration and is highly regulated. A novel regulatory mechanism to control c-Src function that has recently been identified involves the C-terminal amino acid sequence Gly-Glu-Asn-Leu (GENL) of c-Src as ligand for PDZ domains. Herein, we determined the biological relevance of this c-Src regulation in human breast epithelial cells. The intact GENL sequence maintained c-Src in an inactive state in starved cells and restricted c-Src functions that might lead to metastatic transformation under normal growth conditions. c-Src with a C-terminal Leu/Ala mutation in GENL (Src-A) promoted the activation and translocation of cortactin and focal adhesion kinase and increased the motility and persistence of cell migration on the basement membrane. Src-A promoted increased extracellular proteolytic activity, and in acinar cultures, it led to the escape of cells through the basement membrane into the surrounding matrix. We ascribe the regulatory function of C-terminal Leu to the role of GENL in modulating c-Src activity downstream of cell matrix adhesion. We propose that the C terminus of c-Src via its GENL sequence presents a mechanism that restricts c-Src in epithelia and prevents progression toward an invasive phenotype.

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