Optimization of Fermentation Conditions for Carrageenase Production by Cellulophaga Species: A Comparative Study

Carrageenases appear in various species of marine bacteria and are widely used for the degradation of carrageenans, the commercially significant sulphated polysaccharides. The carrageenase production ability of six different Cellulophaga species was identified, with ι-carrageenase being the most abundant carrageenolytic enzyme. C. algicola was the most potent strain, followed by C. fucicola and C. geojensis, whereas C. pacifica was the least effective carrageenase producer among the studied strains. The enzyme production was maximized using the one-factor-at-a-time optimization method. The optimal incubation temperature was identified as 25 °C and the incubation time was set as 48 h for all tested species. The optimal medium composition for Cellulophaga strains was determined as 30 g/L sea salt, 1.4 g/L furcellaran, and 3 g/L yeast extract. An ultrafiltered enzyme extracted from C. algicola had the highest activity at around 40 °C. The optimal pH for enzymatic degradation was determined as 7.8, and the enzyme was fairly stable at temperatures up to 40 °C.

The effect of Sulphated cellulose on System of Haemostasis

Experimental studies and analyses of new compounds with different mechanisms of action on systemic haemostasis are relevant for the identification and development of potential pharmacological preparations. The modified sulphated polysaccharides with anticoagulant and antithrombin activity were studied for haemostasis. Platelet-rich plasma was obtained by centrifugation at 200g for 10 minutes. The remaining citrate blood was further centrifuged at 1500g for 10 min to obtain platelet-poor plasma. The antithrombin activity of the compounds was evaluated In vitro by their effect on the recalcification time, thrombin and prothrombin time of rabbit and human blood plasma stabilized with a 3.8% sodium citrate solution in the ratio 9:1. The results showed that the anticoagulant activity of the studied sulphates increased with an increasing degree of sulphation. Sulphated polysaccharides showed strong anticoagulant activity In vitro. The experimental results showed a significant increase in the coagulation time of blood plasma in tests for prothrombin and thrombin time. These properties of these components are of particular interest, and further detailed studies of the physicochemical characteristics and mechanisms of action of these molecules should be performed, which will eventually allow them to be used as heparin-like drugs.

Immunomodulatory and Antiviral Effects of Macroalgae Sulphated Polysaccharides: Case Studies Extend Knowledge on Their Importance in Enhancing Shellfish Health, and the Control of a Global Viral Pathogen Ostreid Herpesvirus-1 microVar

Macroalgae are the primary source of non-animal sulphated polysaccharides (SPs) in the marine environment with fucoidans derived from brown algae (Phaeophyta) and carrageenans from red algae (Rhodophyta). Much research has been carried out on SP effects on Asian shrimp species (genera Penaeus and Metapenaeus) but their effect on commercially important bivalve mollusc species is limited and in Pacific oyster Crassostrea gigas is unknown. Knowledge of their impact on bivalve pathogens and Palaemon shrimp is unknown. The objectives of this study were to assess the effects of Fucus vesiculosus (Phaeophyta), Mastocarpus stellatus (Rhodophyta) and algal derivatives (fucoidan and κ-carrageenan) on C. gigas performance, and on ostreid herpesvirus-1 microvar (OsHV-1 μVar) and bacteria Vibrio spp. development. Both pathogens have been associated with significant oyster mortalities and economic losses globally. The effects of sulphated galactan from Gracilaria fisheri (Rhodophyta) on European common prawn Palaemon serratus, an important fishery species, was also assessed. Findings indicate a rapid and prolonged increase in total blood cell count, lysozyme (enzyme that destroys pathogens), and a difference in the ratio of blood cell types in treated individuals compared to their control counterparts. A significantly lower OsHV-1 μVar prevalence was observed in treated oysters and κ-carrageenan was found to suppress viral replication (loads), while OsHV-1 μVar was not detected in the fucoidan treated oysters from Day 8 of the 26-day trial. No antibacterial effect was observed however, the oysters did not succumb to vibriosis. These findings contribute further knowledge to macroalgae sulphated polysaccharide biotherapeutic properties, their twofold effect on animal health and viral suppression.

Seaweeds

Seaweeds are microalgae growing in coastal regions and resistant to salinity. Seaweeds are rich resources of natural nutrients some of which cannot be obtained from terrestrial plants. Bioactive compounds of seaweeds such as sulphated polysaccharides, peptides, minerals, phlorotannins, carotenoids and sulfolipids have proven health benefits against various diseases. Traditionally, seaweeds are used as folk medicine for treating diseases like goiter, wounds, burns, rashes, inflammation, diabetes and also gaining attention of pharmaceutical industries due to their anti-cancer, anti-aging, anti-angiogenesis, anti-bacterial, anti-viral and antioxidant properties. Seaweeds polysaccharides have wide applications in foods as well as in pharmaceutical industry due to their bio-chemical properties such as stabilizer, emulsifier and gelling property. In food industry, seaweed polysaccharides are used as a functional ingredient in many products such as frozen foods, ice-cream, jam, jelly, beverages etc. Several commercial food preparations from seaweeds are also available in the market such as sea salt, nori snack wasabi, pink rock salt, seaweed thins toasted coconuts, crunchy seaweed chips, raw unroasted seaweed under different brand names. The present review is a compilation of nutritional, pharmacological and food properties of seaweeds along with its potential towards development of functional foods.

Highly Sensitive Fluorescence Sensor for Carrageenan from a Composite Methylcellulose/Polyacrylate Membrane

Carrageenans are linear sulphated polysaccharides that are commonly added into confectionery products but may exert a detrimental effect to human health. A new and simpler way of carrageenan determination based on an optical sensor utilizing a methylcellulose/poly(n-butyl acrylate) (Mc/PnBA) composite membrane with immobilized methylene blue (MB) was developed. The hydrophilic Mc polymer membrane was successfully modified with a more hydrophobic acrylic polymer. This was to produce an insoluble membrane at room temperature where MB reagent could be immobilized to build an optical sensor for carrageenan analysis. The fluorescence intensity of MB in the composite membrane was found to be proportional to the carrageenan concentrations in a linear manner (1.0–20.0 mg L−1, R2 = 0.992) and with a detection limit at 0.4 mg L−1. Recovery of spiked carrageenan into commercial fruit juice products showed percentage recoveries between 90% and 102%. The optical sensor has the advantages of improved sensitivity and better selectivity to carrageenan when compared to other types of hydrocolloids. Its sensitivity was comparable to most sophisticated techniques for carageenan analysis but better than other types of optical sensors. Thus, this sensor provides a simple, rapid, and sensitive means for carageenan analysis.