Optimization of R-Phycoerythrin Extraction by Ultrasound-Assisted Enzymatic Hydrolysis: A Comprehensive Study on the Wet Seaweed .

Enzyme-assisted extraction (EAE) and ultrasound-assisted extraction (UAE) are both recognized as sustainable processes, but little has been done on the combined process known as ultrasound-assisted enzymatic hydrolysis (UAEH), and even less on seaweed. The present study aimed to optimize the UAEH of the red seaweed for the extraction of R-phycoerythrin (R-PE) directly from the wet biomass by applying a response surface methodology based on a central composite design. Three parameters were studied: the power of ultrasound, the temperature and the flow rate in the experimental system.

, A Novel Cosmopolitan Species of Blue Diatoms.

Specimens of a new species of blue diatoms from the genus Simonsen were discovered in geographically distant sampling sites, first in the Canary Archipelago, then North Carolina, Gulf of Naples, the Croatian South Adriatic Sea, and Turkish coast of the Eastern Mediterranean Sea. An exhaustive characterization of these specimens, using a combined morphological and genomic approach led to the conclusion that they belong to a single new to science cosmopolitan species, sp. nov.

Data on the sensory characteristics and chemical composition of the edible red seaweed dulse () after dry and semi-dry storage.

The data article refers to the paper "Semi-dry storage as a maturation process for improving the sensory characteristics of the edible red seaweed dulse ()" [1]. The data refers to the analysis of samples of the edible seaweed species during storage in a dry (D, containing ca. 6 % moisture) and semi-dry state (SD, containing ca.

Extraction and Purification of R-phycoerythrin from Marine Red Algae.

This chapter focuses on the recovery of an R-Phycoerythrin (R-PE)-enriched fraction from marine algae. Since R-PE is a proteinaceous pigment, we have developed a simple and rapid two-step method devoted to the extraction and purification of R-PE from marine red algae. Here we describe a phosphate buffer extraction followed by anion exchange chromatography carried on a DEAE Sepharose Fast Flow column.

One-step purification of R-phycoerythrin from the red edible seaweed Grateloupia turuturu.

A one-step chromatographic method for the purification of R-phycoerythrin (R-PE) of Grateloupia turuturu Yamada is described. Native R-PE was obtained with a purity index of 2.89 and a recovery yield of 27% using DEAE-Sepharose Fast Flow chromatography with a three-step increase in ionic strength.

Marennine, promising blue pigments from a widespread Haslea diatom species complex.

In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, presents different biological activities: allelopathic, antioxidant, antibacterial, antiviral, and growth-inhibiting.

Physicochemical factors affecting the stability of two pigments: R-phycoerythrin of Grateloupia turuturu and B-phycoerythrin of Porphyridium cruentum.

Phycoerythrin is a major light-harvesting pigment of red algae, which could be used as a natural dye in foods. The stability of R-phycoerythrin of Grateloupia turuturu and B-phycoerythrin of Porphyridium cruentum in relation to different light exposure times, pHs, and temperatures was studied. Regarding the light exposure time, after 48h, the reduction in concentrations of B-phycoerythrin and R-phycoerythrin were 30±2.

Non-methylene interrupted and hydroxy fatty acids in polar lipids of the alga Grateloupia turuturu over the four seasons.

Phospholipids (PL) and glycolipids (GL) FA in the edible Rhodophyta Grateloupia turuturu, from Brittany, France, were investigated over four seasons. The major lipid class was GL in all seasons (around 45 %). More than 80 FA occurred in polar lipids, with chains from C12 to C26, identified as methyl esters and N-acyl pyrrolidides by gas chromatography-mass spectrometry (GC-MS).

Optimization of hydrolysis conditions of Palmaria palmata to enhance R-phycoerythrin extraction.

In this study, response surface methodology was applied to optimize R-phycoerythrin extraction from the red seaweed Palmaria palmata, using enzymatic digestion. Several algal treatments prior to digestion were first investigated. The extraction yield and the purity index of R-phycoerythrin, and the recovery of proteins and reducing sugars in the water-soluble fraction were then studied in relation to the hydrolysis time, the temperature and the enzyme/seaweed ratio.

Biological activities of purified marennine, the blue pigment responsible for the greening of oysters.

Marennine, the blue pigment produced by the diatom Haslea ostrearia , exists in two different forms, the intra- and extracellular forms. We investigated the antibacterial, antiviral, and antiproliferative properties of both of these forms. Both forms of marennine inhibited the development of marine bacteria, in particular the pathogenic organism Vibrio aesturianus , at concentrations as low as 1 μg/mL, but they did not display any effect on a wide range of pathogenic bacteria that are relevant for food safety.

Search for hydrophilic marine fungal metabolites: a rational approach for their production and extraction in a bioactivity screening context.

In the search for bioactive natural products, our lab screens hydrophobic extracts from marine fungal strains. While hydrophilic active substances were recently identified from marine macro-organisms, there was a lack of reported metabolites in the marine fungi area. As such, we decided to develop a general procedure for screening of hydrophobic metabolites.

Antioxidant and free radical scavenging properties of marennine, a blue-green polyphenolic pigment from the diatom Haslea ostrearia (Gaillon/Bory) Simonsen responsible for the natural greening of cultured oysters.

Among microalgae, the marine diatom Haslea ostrearia has the distinctive feature of synthesizing and releasing, into the surrounding environment, a blue-green polyphenolic pigment called marennine. The oyster-breeding industry commonly makes use of this natural phenomenon for the greening of oysters grown in the ponds of the French Atlantic coast. This article reports the in vitro antioxidant properties of pure marennine.

Milli-calpain from sea bass (Dicentrarchus labrax) white muscle: purification, characterization of its activity and activation in vitro.

A calcium-activated neutral cysteine protease was purified to homogeneity from Dicentrarchus labrax white muscle using three steps: hydrophobic interaction, anion exchange, and gel filtration chromatographies. The purified enzyme showed a native molecular weight of 124 kDa with an oligomeric structure (large subunit of 80 kDa and small subunit of 24 kDa). It has been classified as a milli-calpain from its calcium sensitivity.

Improvement of the digestibility of the proteins of the red alga Palmaria palmata by physical processes and fermentation.

Palmaria palmata (dulse) is an edible red alga constituting a potential protein source in human diet. However, previous studies showed that the digestibility of dulse proteins is bad because of the cell-wall encapsulating cytoplasmic proteins and the presence of fibers. The water-soluble xylan, present in high proportions in dulse, could be involved to explain the weak digestibility of proteins.

Structural studies of the mix-linked beta-(1-->3)/beta-(1-->4)-D-xylans from the cell wall of Palmaria palmata (Rhodophyta).

The structure and organization of Palmaria palmata cell walls, which are largely involved in biological and physiological functions as well as in biotechnological and food applications of this red marine alga, are principally assumed by the interactions and linkages of major mix-linked beta-(1-->3)/beta-(1-->4)-D-xylans. These partly acidic polysaccharides are essentially held in the cell wall by H-bonds. The location of the acid groups and the distribution of 1-->3-linkage were studied following the endo-beta-(1,4)-xylanase hydrolysis of sequentially extracted xylans, and fine analysis of the oligosaccharides produced by anion exchange chromatography, high performance anion exchange chromatography (HPAEC)-PAD, nuclear magnetic resonance (NMR) and electrospray ion trap mass spectrometry (ESI-MS) techniques.

Molecular phylogeny and species identification of sardines.

The DNA sequence diversity of Sardina pilchardus (Walbaum, 1792) and some closely related species of Clupeomorpha was investigated using the mitochondrial DNA gene encoding cytochrome b. The nucleotide sequences of complete and partial mtDNA cytochrome b were determined in numerous specimens. Sequence divergence between species and genera was evenly distributed in the cytochrome b gene but rather high compared to reports for other fish species.