Temporal variations in growth of the giant kelp Macrocystis pyrifera were examined in relation to ambient nutrient availability and chemical composition of mature blades, the primary site of nutrient and carbohydrate storage in M. pyrifera. The effect of nutrient availability on growth was well approximated by a Monod rectangular hyperbola, with growth saturating at ambient nitrate concentrations between 1 and 2 FM. M. pyrlfera was unable to generate nutrient reserves that would last beyond 30 d. Nitrogen reserves were stored as free amino acids, and generally constituted about 10 % of total tissue nitrogen. Total nitrogen content was never more than 2 .5% of dry weight. There was no significant corrc.lation between growth and tissue nitrogen. In contrast, carbohydrate levels were negatively correlated with growth rates, tissue nitrogen content, and ambient nutrient availability. Although concentrations of nitrogen and carbohydrate reserves showed familiar variations described for other kelps, the physical environment in southern California is probably not amenable to M. pyrifera making strategic use of these reserves. Nutrient availability appears to be too low to permit accumulation of more than 30 d reserve of nitrogen, and light levels are probably never low enough to make stored carbohydrate reserves necessary for survival.
Digital library
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Background: Seaweeds are taxonomically diverse benthic algae, which are rich in bioactive compounds. These compounds have a potential application in medicine.
Objectives: The aim of the study was to investigate the bioactive properties of three seaweed samples, Enteromorpha antenna, Enteromorpha linza and Gracilaria corticata were collected from the shoreline of Mahabalipuram, Tamilnadu.
Materials and Methods: Bioactive components were extracted by using various solvents. Antioxidant analysis methods like scavenging activity of nitric oxide, hydrogen peroxide, hydroxyl radicals, free radical scavenging (DPPH), FRAP (ferric reducing ability plasma) ability and reducing power were carried out. MTT assay was employed to study the anticancer activity against cancer cell lines Hep-G2, MCF7 and normal VERO cell lines.
Results: It was found that methanolic extracts elicited higher total phenolic content, higher percentage scavenging activity of nitric oxide, hydrogen peroxide, hydroxyl radicals, free radical scavenging (DPPH), FRAP (ferric reducing ability plasma) ability and reducing power. Different concentrations of crude methanolic extracts of seaweeds showed potential antimicrobial activity by well diffusion method. Crude methanolic extract of G. corticata had significant anticancer activity followed by E. antenna and E. linza on cancer cell lines Hep-G2, MCF7 and normal VERO cell lines by MTT assay.
Conclusions: The methanolic extracts of seaweeds Enteromorpha antenna, Enteromorpha linza and Gracilaria corticata possess high total phenolic content and shows a good free radical scavenging activity and hence are proven to have better antioxidant activity and they might be good candidates for further investigations in order to develop potential anticancer drugs.
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Six antimicrobial-producing seaweed-derived Bacillus strains were evaluated in vitro as animal probiotics, in comparison to two Bacillus from an EU-authorized animal probiotic product. Antimicrobial activity was demonstrated on solid media against porcine Salmonella and E. coli. The marine isolates were most active against the latter, had better activity than the commercial probiotics and Bacillus pumilus WIT 588 also reduced E. coli counts in broth. All of the marine Bacillus tolerated physiological concentrations of bile, with some as tolerant as one of the probiotics. Spore counts for all isolates remained almost constant during incubation in simulated gastric and ileum juices. All of the marine Bacillus grew anaerobically and the spores of all except one isolate germinated under anaerobic conditions. All were sensitive to a panel of antibiotics and none harbored Bacillus enterotoxin genes but all, except B. pumilus WIT 588, showed some degree of β-hemolysis. However, trypan blue dye exclusion and xCELLigence assays demonstrated a lack of toxicity in comparison to two pathogens; in fact, the commercial probiotics appeared more cytotoxic than the majority of the marine Bacillus. Overall, some of the marine-derived Bacillus, in particular B. pumilus WIT 588, demonstrate potential for use as livestock probiotics.
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Utilisable crude protein (uCP), methane (CH4) production and other fermentation parameters were analysed in vitro for a diet in which grass silage was replaced by different levels of seaweed protein fractions prepared from three seaweed species: Saccharina latissima, Alaria esculenta and Palmaria palmata. Ten fractions from these three species in which the protein content had been increased and the salt content reduced by simple processing were tested, with inclusion levels in the diet based on the nitrogen content of the fractions. Following an extraction procedure, four fractions from Saccharina latissima, three from Alaria esculenta and one from Palmaria palmata, were incrementally included in the diet by replacing high quality silage with approximately 0, 0.15, 0.30 and 0.45 g/g DM, while two high-protein fractions of Palmaria palmata were tested at replacement levels of 0, 0.075, 0.15 and 0.225 g/g DM. To estimate fermentation parameters, 500 mg of each diet were incubated in bottles with 60 mL buffered rumen fluid. Estimated uCP increased linearly with increasing replacement rate of grass silage with seaweed protein fractions (from 158 g/kg DM to 206 g/kg DM on average for all fractions). Increasing protein fraction from the brown seaweed Saccharina latissima in the diet significantly increased true organic matter digestibility (OMD) (from on average 0.786 to 0.821). Organic matter digestibility decreased with increasing level of Alaria esculenta fractions (from on average 0.785 to 0.733), which also gave a linear decrease in CH4 production (from on average 45.3 to 38.5 mL/g organic matter). As a result of decreased CH4 production and OMD, total volatile fatty acid concentration decreased with increasing level of Alaria esculenta fractions (from on average 69.5 to 63.0 mmol/L). Thus, positive and species-specific effects of seaweed on estimated uCP and fermentation parameters were observed in vitro when protein fractions remaining after an extraction procedure on seaweed partly replaced grass silage in the feed ration.
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The cultivation of seaweeds contributes significantly to the national economy and provides employment to the economically backward communities of Sabah, Malaysia. Cultivation of seaweeds on a commercial scale requires a large number of propagules with desirable phenotypic traits which include high growth rates and resistance to diseases. Thus, seaweed tissue culture can be considered as one of the best methods to provide a large amount of seedlings for commercial cultivation. The parameters which have been determined to have a significant effect on the growth of in vitro propagated Eucheuma seaweeds are the sterilization techniques, media composition, light intensity and aeration. Eucheuma seaweeds were surface sterilized by washing with optimized concentration of disinfectants and antibiotics. The appropriate medium was determined to be Provasoli’s Enriched Seawater (PES) while optimum light intensity was in the range of 6,000 lux. Continuous aeration was important to provide enough carbon dioxide for carbon fixation. Hormone IAA:BAP was provided with concentration ratio of 5:1 mg/l. Temperature was maintained in the range of 25 to 30°C while salinity of the seawater was kept constant at 32 ppt.
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Livestock production, particularly enteric methane production, contributes to greenhouse gas emissions globally. Various mitigation strategies developed to reduce enteric emissions have limited success. Although in vitro studies have shown a considerable reduction in methane emissions using Asparagopsis spp., no studies have been conducted to investigate the effect of any species of Asparagopsis in dairy cattle. Our objective was to evaluate quantitatively the response of cows consuming Asparagopsis armata on methane production (g/kg), yield (g/kg feed intake) and intensity (g/kg milk yield). Twelve post-peak lactating Holstein cows were randomly assigned to three treatments (control, 0.5% and 1% inclusion levels of A. armata on organic matter basis) in a 3 × 3 Latin square design with three 21-day periods. Enteric methane emissions were measured using the GreenFeed system. Methane production by cows decreased significantly by 26.4% at the low (0.5%) level of A. armata inclusion and 67.2% at the high (1%) level of inclusion. Feed intake was reduced by 10.8 and 38.0%, in cows fed the low and high level of macroalgae inclusion, respectively. Methane yield decreased significantly by 20.3 and 42.7% in cows fed diet including 0.5% and 1% A. armata inclusion levels, respectively (P = <0.0001). Methane intensity significantly decreased by 26.8% from cows fed at 0.5% level and 60% at the 1.0% A. armata inclusion level. Bromoform concentrations in milk were not significantly different between treatments. Our in vivo results showed that A. armata has potential to be used as a feed additive to reduce enteric methane emissions.
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This presentation covers
- What seaweeds are
- The history of seaweed cultivation
- The use of seaweed in food, merchandise, medicine, biofuel, fertilizers, animal feed, and etc.
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A PDF on "Industrial utilization of seaweed in Norway".
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This study was conducted during the growing season of 2016 in a private orchard at AL-Abbasyia , Najaf Governorate on the local fig cv. Aswod Diala . The trees were sprayingwithamino acids(Amister and Gusto) at concentrations of 500 mg / L each other, Bleed of grape 100% and seaweed Ascophyllum nodosum at concentrations of 4% in single way or in combination at 15 march and 15 May,2016 . Results showed that sprayingwithamino acids ,bleed grape and seaweed extracttreatments and their interactions caused a significant increase percentage of leaf area ,total chlorophyll,length of shoots , percentage of carbohydrate in branches , percentage of nitrogen in branches , percentage of carbohydrate / nitrogen in branches , percentage of nitrogen in leaves, percentage of phosphor in leaves, percentage of potassium in leaves ,diameter of fruit , length of fruit , weightof fruit , percentage humidity of fruit , percentage dray matter of fruit, number of days to ripening ,percentage of total soluble sold , fruit firmnessand total yield of trees compared with control treatment . There were significant differences between above mentioned treatments. TheBleed of grape was more effective than amino acids(Amister and Gusto) and seaweed in that respect , but the combination of amino acids(Amister and Gusto) , Bleed of grape and seaweed gave the best results in the treatment ( Am + Gu+Bg + Bs) for the season of experiment.
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The European Commission opened a discussion about limiting first generation food based biofuels in favour of advanced biofuels. The main reason was to limit the uncertainty in estimates of indirect land use change emissions (ILUC) of food based biofuels. Brown seaweeds represent a valuable solution. The lack of lignin makes them suitable for degradation processes such as anaerobic digestion (AD). The main output of AD is biogas which can be upgraded to biomethane and used as a transport fuel. The most common Irish brown seaweeds namely Laminaria sp. and Ascophyllum nodosum were subject to AD. The effects of beating pretreatment time (5e10e15 min) and changes in the seaweeds volatile solids (VS) concentration (1e2.5e4%) on methane production were investigated through a response surface methodology (RSM). Laminaria sp. showed the highest methane yield of 240 ml CH4 g1 VS when the pretreatment time was set at 15 min and at VS concentration of 2.5%. In the case of Ascophyllum nodosum, the best yield of 169 mL CH4 g1 VS was found at the longest pretreatment time tested and at the minimum concentration of VS. The RSM analysis revealed that the VS concentration had the strongest impact on the methane yield.
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Marine Agronomy Group, CAFNRM, UH-Hilo
200 W. Kawili st., HI 96720, USA
Contact: Marine.Agronomy.Group@gmail.com
Funding for this web portal is provided by the World Wildlife Fund and the University of Hawaii-Hilo.