Periodic Reporting for period 2 - GHaNA (The Genus Haslea, New marine resources for blue biotechnology and Aquaculture)
Berichtszeitraum: 2019-03-01 bis 2022-08-31
The H2020 ‘GHaNA’ (The Genus Haslea, New marine resources for blue biotechnology and Aquaculture, 2017-2023) project was a Marie Sklodowska-Curie Actions (MSCA) - Research and Innovation Staff Exchanges program dedicated to promote international and intersectoral collaboration. The consortium gathered 25 academic and private institutions from 13 different countries. The GHaNA project aimed at exploring the diversity of a peculiar marine microalgal resource, the diatom of the genus Haslea, for blue biotechnology applications in aquaculture, cosmetic, food and health industry. Some Haslea species are unique among microalgae, being able to produce large amounts of water-soluble bluish pigments, as the type species of the genus, Haslea ostrearia that synthesizes marennine, in reference to Marennes Bay (France), a region historically famous for its oyster industry. When released into seawater, marennine turns oysters green. The research on the origin of the color intrigued generations of botanists and chemists and the chemical nature of the pigment has not been elucidated yet. Marennine also displays biological activities such as antiproliferative, antioxidant, antibacterial, antiviral, with a great potential for industrial exploitation.
The main innovative outcomes of GHaNA are:
- an increased knowledge in the diversity of the genus Haslea (4 blue and 3 non-blue new species)
- the sequencing of H. ostrearia genome using Illumina and next-generation sequencing (NGS) techniques
- the observation of blue Haslea blooms in natural environments in the Mediterranean Sea and the Adriatic Sea
- the assessment of the photobiology and photoprotection mechanisms in H. ostrearia
- progress in the design of photobioreactors to develop automated culture of blue Haslea to ensure the production of marennine-like pigments using ultrafiltration membranes, and collect associated high-value compounds, e.g. terpenoids, lipids, silica skeletons from the residual waste biomass
- the description of isoprenoid biosynthesis pathway in H. ostrearia
- new insights on the structure of marennine, a polydisperse heteropolysaccharide associated to a still uncharacterized chromophore
- the assessment of prophylactic and anti-vibrio effects of marennine and application to bivalve hatchery
- first observation of marennine effects in angiogenesis and oncology
- preliminary results of marennine as natural pigment for textile industry
The main innovative outcomes of GHaNA are:
- an increased knowledge in the diversity of the genus Haslea (4 blue and 3 non-blue new species)
- the sequencing of H. ostrearia genome using Illumina and next-generation sequencing (NGS) techniques
- the observation of blue Haslea blooms in natural environments in the Mediterranean Sea and the Adriatic Sea
- the assessment of the photobiology and photoprotection mechanisms in H. ostrearia
- progress in the design of photobioreactors to develop automated culture of blue Haslea to ensure the production of marennine-like pigments using ultrafiltration membranes, and collect associated high-value compounds, e.g. terpenoids, lipids, silica skeletons from the residual waste biomass
- the description of isoprenoid biosynthesis pathway in H. ostrearia
- new insights on the structure of marennine, a polydisperse heteropolysaccharide associated to a still uncharacterized chromophore
- the assessment of prophylactic and anti-vibrio effects of marennine and application to bivalve hatchery
- first observation of marennine effects in angiogenesis and oncology
- preliminary results of marennine as natural pigment for textile industry
To address the biodiversity of the genus Haslea, many phytoplankton sampling campaigns were conducted. Samples were collected from sites along the coasts of all continents and strains characterized. The use of molecular markers has shown that some newly species belong to a group within the genus Navicula, a close relative of Haslea. These Haslea-like diatoms could be accommodated in a new genus, provisionally named Pseudo-haslea.
According to last experimental data, marennine is constituted by a glycosidic backbone to which a chromophore is linked. Work is in progress to understand the linkage between and the spatial disposition of the monosaccharides and to determine the nature of the chromophore.
Regarding photophysiology, the work investigated photoadaptation capacities and photoacclimation strategies, comparing Haslea strains originating from different geographic areas from the Arctic to the Equator. Haslea diatoms rapidly, but transiently, upregulate electron transport following changes in light environment. This is of essential importance for blue biotechnology, for photobioreactor control of biomass yield and possibly marennine or high-value compounds production.
The chemical diversity of isoprenoids and blue pigments produced by different Haslea strains has also been investigated. Transcriptomic together with genomic information was mined for the identification of enzyme candidates for the synthesis of highly branched isoprenoids and the corresponding genes were analyzed using heterologous expression systems for the characterization of bioactivity.
For aquaculture, the possible impact of marennine was studied on a broad panel of marine microorganisms and invertebrates. Different pathogenic bacteria of the genus Vibrio exposed to environmentally relevant concentrations of marennine revealed usually sensitive, being inhibited, more rarely stimulated. Experiments were conducted on embryos or larvae of different marine invertebrates, and challenge tests with pathogen cultures or with infected hosts protected by marennine were realized on Pacific oyster adults, blue mussel larvae and juvenile, American oyster larvae. Marennine demonstrated a significant protective effect at low concentration, but showed toxic effect at high concentration on larvae or transient negative impact on the physiology of adult oysters. These results could limit the conditions of use of marennine on larvae for shellfish aquaculture.
Regarding the formation issue, one of the most valuable impacts of GHaNA relates to the many early stage researchers who made secondments in the consortium hosting institutions. They were trained in the use of new instruments, techniques, databases and programs. They also attended trainings about safety issues, transferable skills, learned foreign languages and participated in social activities to discover the hosting countries. This has boosted their careers, by making them more efficient, mobile across different countries, independent, more organized and experienced researchers.
The project was presented by the different partners involved to high school students visiting the universities, to the non-specialist public during events such as the European researchers nights, during science festivals and radio emissions. Haslea and marennine inspired the artwork of two French filmmakers and a glass sculptor.
According to last experimental data, marennine is constituted by a glycosidic backbone to which a chromophore is linked. Work is in progress to understand the linkage between and the spatial disposition of the monosaccharides and to determine the nature of the chromophore.
Regarding photophysiology, the work investigated photoadaptation capacities and photoacclimation strategies, comparing Haslea strains originating from different geographic areas from the Arctic to the Equator. Haslea diatoms rapidly, but transiently, upregulate electron transport following changes in light environment. This is of essential importance for blue biotechnology, for photobioreactor control of biomass yield and possibly marennine or high-value compounds production.
The chemical diversity of isoprenoids and blue pigments produced by different Haslea strains has also been investigated. Transcriptomic together with genomic information was mined for the identification of enzyme candidates for the synthesis of highly branched isoprenoids and the corresponding genes were analyzed using heterologous expression systems for the characterization of bioactivity.
For aquaculture, the possible impact of marennine was studied on a broad panel of marine microorganisms and invertebrates. Different pathogenic bacteria of the genus Vibrio exposed to environmentally relevant concentrations of marennine revealed usually sensitive, being inhibited, more rarely stimulated. Experiments were conducted on embryos or larvae of different marine invertebrates, and challenge tests with pathogen cultures or with infected hosts protected by marennine were realized on Pacific oyster adults, blue mussel larvae and juvenile, American oyster larvae. Marennine demonstrated a significant protective effect at low concentration, but showed toxic effect at high concentration on larvae or transient negative impact on the physiology of adult oysters. These results could limit the conditions of use of marennine on larvae for shellfish aquaculture.
Regarding the formation issue, one of the most valuable impacts of GHaNA relates to the many early stage researchers who made secondments in the consortium hosting institutions. They were trained in the use of new instruments, techniques, databases and programs. They also attended trainings about safety issues, transferable skills, learned foreign languages and participated in social activities to discover the hosting countries. This has boosted their careers, by making them more efficient, mobile across different countries, independent, more organized and experienced researchers.
The project was presented by the different partners involved to high school students visiting the universities, to the non-specialist public during events such as the European researchers nights, during science festivals and radio emissions. Haslea and marennine inspired the artwork of two French filmmakers and a glass sculptor.
A new method of great application potential has been developed to extract marennine from the supernatant. It provides a very concentrated solution using a simpler and more efficient protocol than previously in use, and a patent describing this new procedure has been filed, which has raised some interests in industry companies from the textile, food and health sectors. To exploit the patent, a funding has been obtained from the Société d’Accélération du Transfert de Technologies Ouest Valorisation to work on the production of biomass and the chemical structure analyses.
Two new projects were funded by the Région Pays de la Loire, to study marennine redox behavior in view of its application as sensitive element in oxygen or pH sensors, and to work on the characterization of the protein and carbohydrate fractions of Haslea biomass. Moreover, two PhD projects were funded to identify marennine-like pigments and up-scale Haslea production in photobioreactors (co-funding Institut France-Québec pour la coopération scientifique en appui au secteur maritime).
New challenges have emerged with GHaNA, mainly resulting from the worldwide observation of blue Haslea blooms in natural environments, and the fast development of omics and blue biotechnologies. A PhD project aimed at studying the development of yearly blue Haslea blooms, to understand the determinism of these blooms and the possible impacts on marine flora and fauna.
Last, recent results on marennine bioactivity opened a new and promising research avenue concerning anti-angiogenic, anti-cancer and anti-inflammatory activities.
Two new projects were funded by the Région Pays de la Loire, to study marennine redox behavior in view of its application as sensitive element in oxygen or pH sensors, and to work on the characterization of the protein and carbohydrate fractions of Haslea biomass. Moreover, two PhD projects were funded to identify marennine-like pigments and up-scale Haslea production in photobioreactors (co-funding Institut France-Québec pour la coopération scientifique en appui au secteur maritime).
New challenges have emerged with GHaNA, mainly resulting from the worldwide observation of blue Haslea blooms in natural environments, and the fast development of omics and blue biotechnologies. A PhD project aimed at studying the development of yearly blue Haslea blooms, to understand the determinism of these blooms and the possible impacts on marine flora and fauna.
Last, recent results on marennine bioactivity opened a new and promising research avenue concerning anti-angiogenic, anti-cancer and anti-inflammatory activities.