Seaweed Samples Research Articles

Heavy metals and potential risks in edible seaweed on the market in Italy

The seaweed food has always been important in Asia, but recently increased in the Western diet.Superfood known for health benefits and rich in essential elements, can also accumulate high contents of heavy metals and iodine from the environment, becoming a health hazard. In particular for iodine, an appropriate labelling of seaweed is needed to warn the consumer of the potential risks. The aim of the study was to analyze the content of 20 heavy metals in seaweeds, distributed in Italy, by ICP-MS, also determining iodine and arsenic (total and inorganic fraction).A total of 72 samples of European and Asian seaweed of 8 genera were analyzed and the results correlated the content of heavy metals to genus, geographical origin and type of sample; 8.33% of the products lacked in the label of the indications of allergens, while 9.72% had irregularities in the label language.The highest concentration of elements was found in the Rhodophyta. The Aluminum level was the highest in the mixed seaweed (165.39 mg/kg) and for the Cadmium in the Asian seaweed (1.16 mg/kg). The amounts of Iron, Zinc and Magnesium, was highest in the Asian seaweed. The values of Arsenic (total and inorganic contents) were compared with the limits: 2.78% exceeds France and USA limits for inorganic, while higher content of total was found in Phaeophyta, which also showed the highest Iodine content (6770.80 mg/kg) that can be dangerous if not reported correctly in the label.

Risk assessment of iodine intake from the consumption of red seaweeds (Palmaria palmata and Chondrus crispus).

Seaweeds are a basic food in the Asian diet. The search for functional and healthy foods has increased the seaweed consumption in Europe and the USA. Seaweeds are a source of essential elements such as iodine. However, high intake levels of iodine can cause damages to human health. Red seaweeds like dulse (Palmaria palmata) and Irish moss (Chondrus crispus) are common in shops and large stores. The iodine level in 30 samples of red seaweeds (dulse and Irish moss) has been determined by redox volumetry with sodium thiosulfate to determine the iodine content of both species and to assess the iodine dietary exposure from dulse and Irish moss consumption. Irish moss (3.86 ± 1.49 mg/kg dry weight) has the highest average iodine content. Four grams per day of dehydrated Irish moss seaweeds contributes greatly to the iodine recommended daily intake (DRI) for children (25.7%). The consumption of analyzed seaweeds (4 g/day) does not pose a health risk. However, the consumption of 286 g/day of Irish moss would lead to exceeding the UL for the adult population set at 1100 μg/day. It is necessary that the consumer respects the consumption guidelines of the seaweed packers.

Preliminary screening of the aqueous extracts of twenty-three different seaweed species in Sri Lanka with in-vitro and in-vivo assays

BackgroundSeaweeds are an important source of bioactive compounds which are applied in various aspects of medicinal investigations. The present study was conducted to investigate cytoxicity (in-vitro and in-vivo) and wound healing activity of different seaweed species in Sri Lanka. MethodsTwenty-three seaweed samples, belonging to Phaeophyta (Brown), Chlorophyta (Green) and Rhodophyta (Red) were used for the experiments. Samples were collected from the inter-tidal and the sub-tidal habitats around Sri Lankan coast (Southern, Northern and North-western). Aqueous seaweed extracts were tested for cytotoxic and wound healing activity; in-vitro and in-vivo. To determine toxicity of aqueous seaweed extracts, brine shrimp lethality assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay on mouse fibroblasts (L929) cell line were performed. Cell migration induction of seaweed extracts was assessed by scratch wound healing assay using L929 cell line. Based on the our previous experiments S.ilicifolium (SW23) was selected for the in vivo study to confirm our hypothesis. Albino mice (BALB/c) were divided into three groups (12 in each) and a circular area (44.07 ± 02.51 mm2) of full skin was excised to create a wound in mice group II and III. Group III received aqueous extract of Sargasum illicifolium (400 mg/kg BW/day for 12 days, orally), Group II received distilled water for 12 days whereas Group I was used as the control group and it was tested without forming wounds and without providing any treatment. Further, the expression level of Tumor Necrosis Factor (TNF-α) and Transforming Growth Factor-β (TGF-β) via RT-PCR were measured every three days until the end of the experiment. ResultsPhytochemical tests showed positive results to flavonoids in all the selected green seaweeds and alkaloids were observed in red seaweeds. In the toxicity assay, red seaweed, Acanthophora spicifera (SW17) was found to be highly effective on nauplii of brine shrimp (LC50 = 0.072 μg/μl). LC50 value of green seaweed species, Caulerpa racemosa (SW02 and SW08) and Caulerpa sertularioides (SW10) was not found within the tested concentration series. The highest cytotoxic effect on L929 cell line was exhibited by aqueous extracts of red seaweed; Jania adhaereus with 50.70 ± 7.304% cell viability compared with control group. The highest cell migration activity was observed in L929 cell line group treated with extracts of green seaweed namely; Halimeda opuntin (SW07) and extracts of brown seaweed namely; Stoechospermum polypodioides (SW11). Extracts of S. illicifolium (SW23) exhibited a significantly enhanced wound healing activity in mice group III within three days (P < 0.05) with an open wound area of 17.35 ± 1.94 mm2 compared with control group (26.29 ± 2.42 mm2). TGF-β gene expression peaked on 6th day of post-wound and subsequently decreased on 9th day of post-wound in mice group III. TNF-α expression was suppressed in mice group III whereas it was elevated in group II. TGF-β expression is enhanced in the treatment group compared to the control group. ConclusionsAqueous extracts of selected seaweeds are a significant source of potential compounds with wound healing properties, which might be helpful in the healing of various wounds. This also infers that many species of brown and red seaweeds have the potential of wound healing, specifically, Sargasum illicifolium and Jania adhaereus could be a potential candidate for in-vivo studies related to wound healing and cancer therapy in the near future.

Antioxidant status of selected sea weeds of Manamelkudi coast, Pudukkottai district

Manamelkudi, located along the Palk Strait of East coast of Tamil Nadu serve as treasure houses for valuable marine resources like sea grass and sea weeds. A study was undertaken at Agricultural College & Research Institute, Kudumiyanmalai during 2016-17 to evaluate the nutritional composition of the seaweeds in order to use them as potential food ingredients. Sea weed samples were collected from Manamelkudi village of Pudukkotai district and were identified as Gracilaria salicornia (C.Agardh) Dawson and Gracilaria edulis (S.G. Gmel.) P.C. Silva Gracilariaceae at Botanical Survey of India, Coimbatore. The samples were washed in sea and fresh water to remove associated organisms and other extraneous matters. The sea weeds were dried, powdered and used for assessing the antioxidant status. G. edulis showed higher activities of enzymic antioxidants superoxide dismutase (312.03 U/g) and catalase (50.1U/g) when compared to G. salicornia (SOD:266.27U/g and CAT:37.1U/g). Maximum levels of the non-enzymic antioxidants, (total phenol and flavonoid) was found in G. edulis when compared to G. salicornia (5.8 and 3.43mg/g; 5.23 and 3.3mg/g respectively). The extent of lipid peroxidation assessed revealed 70.5 and 32.1 percent inhibition by the ethanolic extract of G. edulis and G. salicornia respectively. The results were comparable with that of the standard antioxidant BHT. Phytochemical analysis revealed the presence of alkaloids, carbohydrates, saponins, proteins, aminoacids, phytosterols, phenolic compounds, flavonoids, terpenoids and tannins except saponins and terpenoids in G. salicornia. Thus it can be concluded from the present investigation that both the seaweeds are potentially rich in natural antioxidants and could be used as nutrient supplements in food industry.

DIVERSITY OF CULTIVABLE BACTERIA BY STRATEGIC ENRICHMENT ISOLATED FROM FARMED EDIBLE RED SEAWEED, Gracilaria sp.

Research on bacteria associated with various red seaweed species are emerging due to the interest to understand bacteria-seaweed interaction and functional roles of bacteria in a seaweed environment. Edible red seaweed, Gracilaria sp. is farmed primarily in China, followed by Indonesia and Malaysia but little is known on its associated bacteria and potential functions. This study aimed to isolate and identify cultivable bacteria from extracts of seaweed samples collected from a seaweed cultivation farm in Kedah, Malaysia. The results are hoped to provide insights into beneficial bacteria that exist in the farmed seaweed environment. Through cultivation on strategic enrichment media, 18 isolates OTUs were identified from bacterial phyla Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria. These phyla are ubiquitous in seawater and some isolates were homologous to bacteria in marine host cluster. Further investigation on these isolates is hoped to reveal how the isolated bacteria can be beneficial in a seaweed environment or for other biodiscoveries.

Optimization of the floating-type seaweed dryer

A floating-type solar dryer was designed and fabricated in order to answer the need for a faster and more efficient drying of seaweeds. Based on the results of the several field tests conducted, the developed seaweed dryer was capable of producing good quality dried seaweed products at a shorter drying time as compared to the traditional solar drying methods employed by seaweed farmers. The developed seaweed dryer was likewise proven to be highly adaptable to varying weather conditions. However, like most solar-type dryers, the performance of the fabricated seaweed dryer is greatly affected by weather variations. On a good sunny day, short drying time is expected unlike in cloudy or rainy weather conditions and even during nighttime where air drying can be done, the longer drying period is anticipated. Due to the different drying environments, the optimal dryer settings both for the daytime and cloudy or nighttime conditions must be determined. The optimization study conducted focused on the effects of varying the air inlet of the dryer by opening the foldable sidings to different height levels and the timely operation of exhaust fans in maximizing the combined effect of solar and air drying. An eight-hour drying test was conducted to determine the amount of moisture removed from the seaweed samples which was measured at 30 min interval. The analysis revealed that fully-opened sidings without running exhaust fans setting resulted in the highest moisture reduction in nighttime conditions. On the other hand, the sidings which were opened one-fourth from the bottom without running exhaust fans and sidings half-opened with running exhaust fans settings yielded the highest moisture reduction in daytime condition. In addition, no significant interaction was found between the level of sidings height openings and the operation of the exhaust fans during the nighttime condition. Conversely, there was a significant interaction between the level of sidings height openings and the operation of exhaust fans during the daytime condition.

A novel Enterostomula (Platyhelminthes, Prolecithophora) species from two brackish lakes in Japan.

BackgroundThe genus Enterostomula Reisinger, 1926 belongs to the family Pseudostomidae and comprises generally small and often conspicuously coloured species living on hard bottoms, in gravel and amongst algae. The Pseudostomidae comprises approximately 44 known species from Europe as well as North and South America. Previously, only one species, Allostoma durum, had been recorded in Japan. Known Enterostomula species are predominantly found in marine and brackish habitats.New informationI collected seaweed and sand samples from two brackish lakes near the coast of Shimane Prefecture, Japan and isolated turbellarians from them. The animals were observed as both living and preserved. Here, I describe a novel Enterostomula species with two dorsal black bands and a thick bursal wall.

Chemical Composition and Evaluation of the α-Glucosidase Inhibitory and Cytotoxic Properties of Marine Algae Ulva intestinalis, Halimeda macroloba, and Sargassum ilicifolium.

Seaweed has tremendous potentials as an alternative source of high-quality food products that have attracted research in recent times, due to their abundance and diversity. In the present study, three selected seaweed species commonly found in the Malaysian Peninsular, Ulva intestinalis, Halimeda macroloba, and Sargassum ilicifolium, were subjected to preliminary chemical screening and evaluated for α-glucosidase inhibitory and cytotoxic activities against five cancer cell lines. Chemical composition of U. intestinalis, H. macroloba, and S. ilicifolium methanolic extracts was evaluated by Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Our results revealed the highest total carotenoids (162.00 μg g−1 DW), chlorophyll a (313.09 ± 2.53 μg g−1 DW), and chlorophyll b (292.52 ± 8.84 μg g−1 DW) concentrations in U. intestinalis. In the α-glucosidase inhibitory activity, S. ilicifolium demonstrated the lowest efficacy with an IC50 value of 38.491 ppm compared to other species of seaweed. H. macroloba extract, on the other hand, was found to be the most cytotoxic toward MCF-7 and HT 29 cells with IC50 of 37.25 ± 0.58 and 21.32 ± 0.25 μg/mL, respectively, compared to other cell lines evaluated. Furthermore, H. macroloba extract was also found to be less toxic to normal cell (3T3) with IC50 of 48.80 ± 0.11 μg/mL. U. intestinalis extract exhibited the highest cytotoxicity toward Hep G2 cells with IC50 of 23.21 ± 0.11 μg/mL, whereas S. ilicifolium was less toxic to MDA- MB231 cell with IC50 of 25.23 ± 0.11 μg/mL. Subsequently, the GC-MS analysis of the methanolic extracts of these seaweed samples led to the identification of 27 metabolites in U. intestinalis, 22 metabolites in H. macroloba, and 24 metabolites in S. ilicifolium. Taken together, the results of this present study indicated that all the seaweed species evaluated are good seaweed candidates that exhibit potential for cultivation as functional food sources for human consumption and need to be promoted.

The Effectivity of Plantation Depth on Seaweed Sargassum sp. Growth Using Longline Method

Due to many benefits of seaweed Sargassum sp. makes no longer possible to harvest directly from the habitat, because it may cause disruption of equilibrium in marine ecosystems.One profitable method is longline method. This research objective is to determine the effect of different plantation depth on the growth of seaweed Sargassum sp. with longline cultivation method. This research use four treatments with variation of plantation depths: 25, 50, 75 and 100 cm with 24 seaweed samples and repetition as much as six times per week for 4 weeks, total of 96 samples. The main parameter of this research is the growth of seaweed Sargassum sp. The supporting parameters are water quality parameters such as mineral content, temperature, DO, pH and salinity. The data was treated with ANOVA and continued by Duncan’s test. The results showed that variation of plantation depth gave a highly significant influence (P <0.01) on the growth of seaweed Sargassum sp. with longline method. Treatment with 25 cm plantation depth had the best growth. In the fourth week, there was a significant growth resulted final weight 659.03% from its initial with specific growth rate 6.73%/day or nearly 5 times the growth depth of 100 cm

Hot Water Blanching Pre-Treatments: Enhancing Drying of Seaweeds (Kappaphycus alvarezii S.)

It is really important to dry seaweeds in a shorter drying time without affecting its quality. Thus, this research aimed to investigate the effect of the application of hot water blanching pre-treatments on the drying rate, sensory, and nutritional attributes of seaweed (Kappaphycus Alvarezii, S.). Seaweed samples were blanched (88oC) at 5, 15 and 30 seconds duration and dried using solar glass dryer and heated air mechanical dryer. All samples were replicated three times. Complete Randomized Design (CRD) was used in both dryers and T-Test in comparing between dryers. Simple cost analysis was also performed to assess the annual cost and custom rate of using two methods of drying.It revealed that in heated air mechanical dryer, samples blanched for 5 and 15 seconds dry faster (8 hours). In solar glass dryer, seaweed samples blanched at 5 seconds dry earlier (32.67 hours). Results imply that hot water blanching affects drying time in drying seaweeds and hot water blanching pre-treatments increased drying rate at the initial hour of drying. It verified that models fitted show good predicting capacity and reveals a good correlation coefficient. Hot water blanching pre-treatments and types of dryers did not significantly affect the total ash contents of the seaweed powder, while in crude protein levels, it revealed that hot water blanching pre-treatment was not significant within the dryers but significantly different between drying methods. Moreover, pre-treatments undergone within the dryer were significantly different in crude fiber levels but insignificant in comparison between dryers. It also implied that the color of the seaweed powder dried in solar glass dryer was preferred by panels and all seaweed samples dried using heated air mechanical dryer turned to dark color. Results revealed that hot water blanching pre-treatments and types of dryer do not affect the texture and odor preference of the panels and general acceptability scores of the seaweed powder were insignificantly different within dryers. It also showed that using solar glass dryer and heated air mechanical dryer, it is profitable to blanch the seaweeds before drying.

Variability and Potential of Seaweeds as Ingredients of Ruminant Diets: An In Vitro Study.

Simple SummaryThe use of seaweeds as ingredients of ruminant diets can be an alternative to conventional feedstuffs, but it is necessary to assess their nutritive value. The aim of this study was to analyze the chemical composition and in vitro rumen fermentation of eight brown, red and green seaweed species collected in Norway during both spring and autumn. The in vitro ruminal fermentation characteristics of 17 diets composed of oat hay:concentrate in a 1:1 ratio, with the concentrate containing no seaweed or including one of the 16 seaweed samples, was also studied. Species and season determined differences in chemical composition and in vitro fermentation of seaweeds. Most of the tested seaweeds can be included in the diet (up to 200 g/kg concentrate) without negative effects on in vitro ruminal fermentation.This study was designed to analyze the chemical composition and in vitro rumen fermentation of eight seaweed species (Brown: Alaria esculenta, Laminaria digitata, Pelvetia canaliculata, Saccharina latissima; Red: Mastocarpus stellatus, Palmaria palmata and Porphyra sp.; Green: Cladophora rupestris) collected in Norway during spring and autumn. Moreover, the in vitro ruminal fermentation of seventeen diets composed of 1:1 oat hay:concentrate, without (control diet) or including seaweeds was studied. The ash and N contents were greater (p < 0.001) in seaweeds collected during spring than in autumn, but autumn-seaweeds had greater total extractable polyphenols. Nitrogen in red and green seaweeds was greater than 2.20 and in brown seaweeds, it was lower than 1.92 g/kg DM. Degradability after 24 h of fermentation was greater in spring seaweeds than in autumn, with Palmaria palmata showing the greatest value and Pelvetia canaliculata the lowest. Seaweeds differed in their fermentation pattern, and autumn Alaria esculenta, Laminaria digitata, Saccharina latissima and Palmaria palmata were similar to high-starch feeds. The inclusion of seaweeds in the concentrate of a diet up to 200 g/kg concentrate produced only subtle effects on in vitro ruminal fermentation.

A novel determination method for diuron in seaweed samples: Combination of quadruple isotope dilution strategy with liquid chromatography - quadrupole time of flight - tandem mass spectrometry for superior accuracy and precision

This paper proposed an accurate and sensitive analytical method based on the combination of Liquid Chromatography-Quadrupole Time of Flight-Tandem Mass Spectrometry (LC-QTOF-MS/MS) system with Quadruple Isotope Dilution-Mass Spectrometry (ID4MS) strategy for the determination of diuron at trace levels. In order to achieve accurate and reliable determination of the analyte, ID4MS strategy that uses stable isotopically labelled analogues was employed. Diuron-d6 was synthesized in the laboratory using a novel strategy and employed in ID4MS for the preparation of three calibration blends and seaweed sample blend. The analytical performance of the LC-QTOF-MS/MS method was evaluated and the respective detection and quantification limits obtained were 14.6 µg kg−1 and 46.5 µg kg−1. Good linearity was obtained with a correlation coefficient of 0.9995 over the dynamic range from 50 to 1000 µg kg−1. The validity of the method was successfully tested by carrying out spiking experiments in seaweed samples. The percent recovery value showed superior enhancement for ID4MS strategy (99.97 ± 0.41%) confirming the applicability of the method to complex matrices with great accuracy and precision.

Evaluation of biological activities of some seaweed and seagrass species in the coastal area of Vietnam

Although seaweeds and seagrasses have been used for food and traditional medicine for centuries, merely a small amount of them is exploited and used. Positive biological activities of seaweed and seagrass products on humans, animals and plants have also been recorded for a long time. Vietnam is a tropical country with 3,260 km long coastline and about 350 species of seaweeds, including 60 widely used species. In this study, 57 seaweed and seagrass samples were extracted using CHCl3/MeOH solvent systems and their crude extracts were tested for selected biological actives, including antimicrobial, antioxidant activities and cytotoxicity. The results revealed that 13 out of 57 extracts (accounting for 24.07%) were cytotoxic to one of the two tested cancer cell lines (Hepatocellular carcinoma cell line Hep-G2 and human lung adenocarcinoma cell line LU-1), and 4 extracts (accounting for 7.4%) were cytotoxic to both cancer cell lines. In antimicrobial activity assay, 18 of all 57 extracts (accounting for 37.5%) were capable of inhibiting 1 to 2 test microorganisms and 16 extracts (accounting for 33.33%) inhibited at least 3 test microorganisms. There were solely 1 extract (accounting for 1.85%) of the 57 extracts performing antioxidant activity in DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging assay.

Heavy Metals Bioaccumulation Capacity on Marine Algae Biomass from Romanian Black Sea Coast

Knowledge of environmental pollution with an impact on health is essential for a sustainable environment and useful for people. The coastal areas of the world�s seas and oceans are polluted with different pollutants from technological sources and from other sources of socio-human activities. The pollutants studied are heavy metals Cd, Cu, Zn and Pb. In the paper are presented researches regarding the heavy metal concentrations determined in samples from marine water, sediments and algal mass, harvested from six stations from different areas of the Romanian Black Sea in two different years 2017 and 2018. The analyses were performed in the Chemistry Laboratories of the Faculty of Pharmacy, Ovidius University in Constanta, by a spectrophotometric method using Atomic Absorption Spectrometer ContrAA-700, Analytic Jena AG. For marine water in 2018 the following concentrations were obtained: Zn ] Pb ] Cu ] Cd and in 2017 the order was different: Zn ] Cu ] Pb ] Cd. For sediments in 2017 the order of concentrations is Cu ] Zn ] Pb ] Cd and in 2018 the highest values in the sediment are recorded by the next high values Cu ] Pb ] Zn ] Cd. Constant climate change and increased eutrophication in recent years have led to a massive increase in marine biomass in the Black Sea. For seaweed samples there are accumulations in the order of Zn ] Cu ] Pb ] Cd in both years. Bioaccumulation factors in water BCF water, were higher in algae for Zn and Cu. From the analysis of bioaccumulation factors, it can be noticed that seawater algae accumulate heavy metals from seawater and sediment (confirmed by BCF water ] 1 or BCF sed. ] 1). The accumulation of heavy metals in seaweed shows the existence of pollutants and marine pollution factors. Marine algae are the best biomarkers of pollution.

Effect of drying techniques on color and bioactive potential of two commercial edible Indonesian seaweed cultivars

Seaweeds (Kappaphycus alvarezii and Sargassum duplicatum) are potentially rich sources of bioactive compounds and functional constituents that are used in food applications. Sun, oven, vacuum, and freeze-drying techniques are commonly used seaweed drying techniques and could be classified as cheap (sun and oven) and expensive (vacuum and freeze) drying techniques based on ovens’ market price. Therefore, the study was designed to investigate the effect of cheap (sun and oven) and expensive (vacuum and freeze) drying techniques based on color and antioxidant potential of K. alvarezii and S. duplicatum using phenolic and antioxidant assays. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were employed to discriminate the drying techniques by instrumental color analysis. The results revealed that oven-dried seaweed extracts exhibited higher levels of phenolic (0.30 to 0.36 mg GAE g−1) and antioxidant potential (3.59 to 79.68%). PCA and HCA discriminated the drying techniques into two well-defined groups/clusters I (oven, vacuum, and freeze-drying) and II (sun drying) and revealed higher ΔE values of sun-dried seaweed samples, which was interpreted as color was preserved using drying techniques of cluster I. Overall, oven, vacuum, and freeze-drying techniques reported similarities in color characteristics and could be an alternate drying technique to preserve the color of seaweed cultivars. Therefore, oven drying technique is recommended due to low cost (compared with vacuum and freeze-drying) and an affordable alternative to sun drying, the preferred technique in fishing communities of low-and-middle-income countries, for the development of seaweed-enriched functional foods.

An improved rapid analytical method for the arsenic speciation analysis of marine environmental samples using high-performance liquid chromatography/inductively coupled plasma mass spectrometry.

Arsenic contamination in marine environments is a serious issue because some arsenicals are very toxic, increasing the health risks associated with the consumption of marine products. This study describes the development of an improved rapid method for the quantification of arsenic species, including arsenite (AsIII), arsenate (AsV), arsenocholine (AsC), arsenobetaine (AsB), dimethylarsinic acid (DMA), and monomethyl arsonic acid (MMA), in seaweed, sediment, and seawater samples using high-performance liquid chromatography/inductively coupled plasma-mass spectrometry (HPLC/ICP-MS). ICP-MS based on dynamic reaction cells was used to eliminate spectral interference. Ammonium nitrate- and phosphate-based eluents were used as the mobile phases for HPLC analysis, leading to shorter overall retention time (6 min) and improved peak separation. Arsenicals were extracted with a 1% HNO3 solution that required no clean-up process and exhibited reasonable sensitivity and peak resolution. The optimized method was verified by applying it to hijiki seaweed certified reference material (CRM, NMIJ 7405-a) and to spiked blank samples of sediment and seawater. The proposed method measured the concentration of AsV in the CRM as 9.6 ± 0.6 μg/kg dry weight (dw), which is close to the certified concentration (10.1 ± 0.5 μg/kg dw). The recovery of the six arsenicals was 87-113% for the sediment and 99-101% for the seawater. In the analysis of real samples, AsV was the most abundant arsenical in hijiki and gulfweed, whereas AsB was dominant in other seaweed species. The two inorganic arsenicals (AsIII and AsV) and AsV were the most dominant in the sediment and seawater samples, respectively.

Macrocystis pyrifera source of nutrients for the production of carotenoids by a marine yeast Rhodotorula mucilaginosa.

To evaluate an aqueous extract of Macrocystis pyrifera as a nutrient source for the production of carotenoids by a marine Rhodotorula mucilaginosa isolated from seaweed samples. The effect of different culture conditions on the concentration of biomass and total pigments was evaluated using a Box-Behnken experimental design. The seaweed extract contained 15% ww-1 of protein and 20% ww-1 of carbohydrate; the main sugar in this fraction was trehalose (78%). The culture conditions that maximize the total pigment concentration (1·84±0·03mgl-1 ) were initial pH equal to 7, yeast extract as nitrogen source at a concentration of 4gl-1 , seaweed extract concentration at 25% v v-1 , incubation performed at 25°C and 150revmin-1 during 6days. Under optimal growth conditions, three carotenoids were identified among the pigments produced by R. mucilaginosa, lycopene (38·4±9·4%), β-carotene (21·8±1·5%) and astaxanthin (1·8±0·3%). Carotenoids of commercial interest (lycopene, β-carotene and astaxanthin) can be produced using a marine R. mucilaginosa cultivated with an aqueous extract of M. pyrifera as nutrient source. The total pigment concentration in the culture ranged between 0·82 and 1·84mgl-1 , and was significantly affected by the concentration of the seaweed extract, and yeast extract. This work demonstrates that M. pyrifera can be used as a nutrient source for the production of carotenoids by the marine yeast.

Determination of Iodine Species in Seafood by Ionic Liquid–Based In-line Solid-Phase Extraction-Capillary Electrophoresis

Ionic liquid (IL)–based in-line solid-phase extraction (SPE)-capillary electrophoresis (CE) method was developed for determination of three iodine species (3,5-diiodo-l-thyronine, l-tyrosine, 3,5-diiodo-l-tyrosine) in seafood. The background electrolyte (BGE) used was 5 mM sodium tetraborate. The small SPE extractor filled with Oasis HLB sorbent was constructed and embedded 7.5 cm away from the entrance to the capillary, then the ILs were used as eluting solvents to elute analytes and separate the target compounds to improve the detection sensitivity in CE. Several parameters including the elution solvent, the elution time, pH of sample solution, and sample loading time were investigated. The LODs were 0.48 ng/mL for 3,5-diiodo-l-thyronine, 4.7 ng/mL for l-tyrosine, and 5.2 ng/mL for 3,5-diiodo-l-tyrosine under optimal experimental conditions. Compared with normal hydrodynamic injection, sensitivity enrichment factors for this enrichment strategy ranged from 11 to 9635. The in-line SPE-CE method was then applied to analyze kelp and seaweed samples, and the recoveries ranged from 87 to 117%.

Algicoccus marinus gen. nov. sp. nov., a marine bacterium isolated from the surface of brown seaweed Laminaria japonica.

A Gram-staining-negative, strictly aerobic, non-motile, ovoid- to rod-shaped bacterium, designated as HZ20T, was isolated from the surface of a brown seaweed (Laminaria japonica) sample collected from the East China Sea. Colonies are 1.0-2.0mm in diameter, smooth, circular, convex and yellow after grown on MA at 28°C for 72h. The strain was found to grow at 4-50°C (optimum, 37°C), pH 5.0-9.5 (optimum, pH 7.0-7.5) and with 0-10% (w/v) NaCl (optimum, 1.0-1.5%). Chemotaxonomic analysis showed ubiquinone-8 as the only quinone, C17:0 cyclo, C16:0, summed feature 8 (C18:1ω7c and/or C18:1ω6c) and summed feature 2 (C12:0 aldehyde/unknown 10.9525/C16:1 iso I/C14:0 3OH) as the major fatty acids (> 5%), and diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, one unidentified amino phospholipid, two unidentified phospholipids, five unidentified glycolipid and two unidentified lipids as the polar lipids. The DNA G + C content was 55.5mol%. 16S rRNA gene sequences of the isolate showed highest similarities to Bordetella flabilis AU10664T (97.1%), Parapusillimonas granuli Ch07T (97.1%), Paracandidimonas soli IMT-305T (97.1%), Kerstersia gyiorum LMG5906T (97.0%) and Bordetella sputigena LMG 28641T (97.0%). The phylogenetic trees using 16S rRNA gene and genome sequences both showed that the strain HZ20T formed a deep branch separated from other related genera, indicating that it represents a novel species of a novel genus. The calculated average nucleotide identity (ANI) and percent of conserved proteins (POCP) values using genome sequences of strain HZ20T and related strains also support this conclusion. Based on the phenotypic properties and phylogenetic distinctiveness, we propose strain HZ20T (= MCCC 1K03465T = KCTC 62330T) to represent a novel species of a novel genus with the name Algicoccus marinus gen. nov. sp. nov.

Antibacterial Activity From Seaweeds Turbinaria ornata and Chaetomorpha antennina Against Fouling Bacteria

Biofouling is a serious problem for marine industries, it can damage many constructions which are submerged in the water and the bacteria are the inisiator of that problem. Commercial antifouling agents which have been using widely is not that effective regarding to the after-effect in the ecosystem. Thus, investigating on natural products which can against fouling bacteria is really essential. This research reported the potentials of seaweeds Turbinaria ornata and Chaetomorpha antennina against fouling bacteria which have been tested on the inhibition zone and phytochemical contents. The seaweed samples were extracted using various solvents such as hexane, ethyl acetate and methanol. The results showed that C. antennina had more potentials against the fouling bacteria than T. ornata regarding to the maximum inhibition zone. C. antennina extract had 6 mm at 10 μl/disk when T. ornata only had 2 mm at 10 μl/disk. In addition, C. anteninna extracts also had more phytochemical contents (phenol, flavonoid, steroid, saponin, alkaloid and triterpenoid) than T. ornata extracts (phenol, steroid, saponin, and alkaloid). Having larger maximum inhibition zone and more phytochemical contents indicated that C. anteninna can be the natural source candidate for antibacterial agent especially fouling bacteria.