Biofuels from the Sea: Seaweed May Prove a Viable Future Biofuel, Especially If Harvested

Biofuels from the Sea: Seaweed May Prove a Viable Future Biofuel, Especially If Harvested in Summer

ScienceDaily (July 4, 2011) — Seaweed may prove a viable future biofuel -- especially if harvested in summer. The use of kelp (Laminaria digitata) could provide an important alternative to terrestrial grown biofuels; however the suitability of its chemical composition varies on a seasonal basis. Harvesting the kelp in July when carbohydrate levels are at their highest would ensure optimal sugar release for biofuel production.

"The storage carbohydrate and soluble sugars get converted into ethanol in the fermentation process, so we need as much as possible," explains Dr. Jessica Adams, a lead researcher at Aberystwyth University. "Metals can inhibit the yeast too so we also want these to be as low as possible."

Collecting monthly samples of kelp from the Welsh coast researchers used chemical analysis to assess the seasonal variability. Their results, which will be presented at the Society for Experimental Biology Annual Conference in Glasgow on the 4th of July, showed that the best month for biofuel harvest was in July when the kelp contained the highest proportions of carbohydrate and the lowest metal content.

Kelp can be converted to biofuels in different ways including fermentation or anaerobic digestion producing ethanol and methane or pyrolysis, (a method of heating the fuel without oxygen) which produces bio-oil. The chemical composition of the seaweed is important to both of these processes.

Research into biofuels has focused on terrestrial plants; however these have the serious drawback of the conflict between using land to grow food or fuel. Marine ecosystems are an untapped resource that account for over 50% of global biomass and seaweeds themselves are capable of producing more biomass per square metre than fast growing terrestrial plants such as sugar cane.

"Seaweed biofuel could be very important in future energy production," says Dr. Adams. "What biofuels provide that other renewables such as wind power cannot is a storable energy source that we can use when the wind drops." Future work will improve the viability of the process by identifying and extracting high value substances, such as pigments and phenols, before the rest of the seaweed is used to produce biofuel.

Directions: For each article, Please summarize the article in paragraph form (8-10 sentences). Please address the following questions in your summary.

1. Restate the article source and date.

2. Who conducted the research? (if given)

3. Where was the research conducted and time period?

4. What were their findings? (discuss them in detail)

5. How is this study important to marine science?

6. How is this relevant to what we are studying now?(and your opinion of the article)

Seaweed Does the Heart Good?

ScienceDaily (Sep. 13, 2011) — Researchers at Teagasc have been investigating lipids from a variety of Irish and Canadian seaweed species for their heart-health properties.

In both Ireland and Canada (province of Newfoundland and Labrador), seaweeds have a long tradition of use. In Ireland, for example, approximately 36,000 tonnes of seaweed are harvested annually. Seaweed species of commercial interest in Ireland include Laminaria digitata and Fucus species (Fucus vesiculosus, Fucus serratus and Fucus spiralis), which are harvested primarily for their valuable carbohydrates, Laminarin and Fucoidan, respectively. The value-added sector of the seaweed industry in Ireland has emerged to produce attractive, high-quality products for use as functional body care products and cosmetics.

However, there is, to date, limited activity aimed at exploiting Irish seaweed resources as materials for functional food ingredients with enhanced health benefits that go beyond basic nutrition for the consumer. The NutraMara Research Programme is currently working at developing the area of marine-origin functional foods in Ireland.

Seaweeds are known to contain a number of heart-health compounds, including ACE inhibitors, antioxidants and essential fatty acids (lipids).

As part of a research collaboration with the Memorial University, Newfoundland, Michelle Tierney and Dr Maria Hayes developed methods for the isolation of total lipids from a number of seaweed species.

"Seaweeds are a known source of essential fatty acids, which are thought to reduce thrombosis and atherosclerosis -- factors important in the reduction of the risk of heart disease," explains Dr Hayes.

Of the eight Irish and Newfoundland seaweed species used in this study, the Irish seaweed, Pelvetia canaliculata, had the highest percentage of total lipids per dry weight, followed by the sustainable Irish seaweed Ascophyllum nodosum. Further work is currently underway at the Teagasc Food Research Centre, Ashtown, concerning the bioactivity profiles and bioactive component isolation of all seaweed lipid extracts.