Measuring the greenhouse gas (GHG) intensity of biof uels has become increasingly important in recent years. Studies have shown a significant amount of variation in biofuels made from different feedstocks. In some cases, biofuels are only marginally better than fossil fuel counterparts. In other cases, there are significant improvements in GHG performance.
Digital library
-
-
Partnership aims for fuels, chemicals & co-products from brown seaweed
In California, Bio Architecture Lab announced an agreement with China’s Xunshan Group, the world’s largest grower of brown seaweed and a global ocean fishery and aquaculture company. Under terms of the agreement, the companies will develop an integrated seaweed bio-refinery to produce a low cost carbohydrate for the production of renewable chemicals, fuels, animal feed and a variety of other high value products using Xunshan’s seaweed and Bal’s conversion technology.
-
The incorporation of algae into aquafeed has come in and out of fashion over the past few decades so the aim of the session was to discuss all aspects of this growing and not well understood industry and to agree on four critical areas which will enhance improvement into the future.
It became clear during the discussions of the vast differences on this subject between EU/West where majority is wild harvest and used as hydrocolloids whereas in Asia the majority is farmed and used for food/feed. The need to concentrate in this Think-Tank on Macro as against Micro was also established however there was a complete understanding that both were immensely important and commonalities can be found between the two. Compared to other types of aquaculture, the production of seaweed (macroalgae) is only surpassed by freshwater fishes and represents over 30 per cent of the world wide industry.
Unicellular algae is a heterogeneous product; a mix of proteins, carbohydrates and lipids. In unicellular algae there is much variation in composition between species/strains and the proportion of these can even be affected by the growing conditions. Algae (both macro and micro) are excellent sources of Vitamin A, Vitamin B, Folic Acid, Antioxidants and Carotenoids. Extracts from Seaweed, in a similar fashion to terrestrial plant extracts, have been shown to have a wide range of biological activities.
The two major classes of molecules in seaweeds that have the most potential as functional food ingredients are polysaccharides and polyphenolics. Polyphenolics have proven antioxidant activity, and have been successfully incorporated into drinks and other food consumables. Seaweed polysaccharides are unique, abundant, and cost effectively isolated but need to be partially hydrolyzed for inclusion in various foods due to their gelling properties. Seaweed polysaccharides have been shown to have heparin-like anticoagulation activity, antiviral, immune-enhancing and anticancer activities, cholesterol lowering activity, lipid lowering effects, and blood pressure-lowering benefits amongst many other things.
-
Increasing resource demand, predicted fossil resources shortage in the near future, and environmental concerns due to the production of greenhouse gas carbon dioxide have motivated the search for alternative ‘circular’ pathways. Among many options, microalgae have been recently ‘revised’ as one of the most promising due to their high growth rate (with low land use and without competing with food crops), high tolerance to nutrients and salts stresses and their variability in biochemical composition, in so allowing the supply of a plethora of possible bio-based products such as animal feeds, chemicals and biofuels. The recent raising popularity of Cir- cular Bio-Economy (CBE) further prompted investment in microalgae, especially in combination with wastewater treatment, under the twofold aim of allowing the production of a wide range of bio-based products while bio- remediating wastewater. With the aim of discussing the potential bio-products that may be gained from microalgae grown on urban wastewater, this paper presents an overview on microalgae production with particular emphasis on the main microalgae species suitable for growth on wastewater and the obtainable bio- based products from them. By selecting and reviewing 76 articles published in Scopus between 1992 and 2020, a number of interesting aspects, including the selection of algal species suitable for growing on urban wastewater, wastewater pretreatment and algal-bacterial cooperation, were carefully reviewed and discussed in this work. In this review, particular emphasis is placed on understanding of the main mechanisms driving formation of microalgal products (such as biofuels, biogas, etc.) and how they are affected by different environmental factors in selected species. Lastly, the quantitative information gathered from the articles were used to estimate the potential benefits gained from microalgae grown on urban wastewater in Campania Region, a region sometimes criticized for poor wastewater management.
-
Synthetic dyes have been used for different purposes in various fields, but their continued usage has presented both environmental and health challenges. Therefore, alternative safer dye sources are inevitable. Algae have different pigments with potential for exploitation and usage in different socio- economic sectors. The aim of this study was to bio prospect dyes from macro-algal species of the Indian Ocean marine ecosystem. Six algal samples were collected from Coastal beaches along the Kenyan Indian Ocean during the wet and dry seasons. The samples were processed and used for pigment extraction and screening. Pigments were extracted using ethanol, acetone, diethyl ether and hexane in sequential with distilled water. Subsequently, the crude extracts were analyzed for pigment component using spectrophotometry and qualitatively for presence of active components. From the six species, Ulva reticulata was the best dye producer in ethanol and distilled water. All extracts were coloured green except those from Galaxaura subverticillata which gave a dark red extract in 80% hexane and a brown extract in distilled water. The crude extracts also contained different active components, with phenols being the most common component in ethanol and acetone extracts. This study demonstrates that macro-algae species from the Indian Ocean ecosystem contain useful pigments for biotechnological exploitation. Future studies should focus on increasing the pigment content through genetic manipulation of macroalgae and analysis of the pigments using modern methods such as the gas chromatography-mass spectrometry (GC-MS).
-
This study examined the bioaccumulation of the heavy metals copper (Cu) and zinc (Zn) by the giant kelp, Macrocystis pyrifera, by exposing meristematic kelp tissue to elevated metal concentrations in seawater within laboratory aquaria. Specifically, we carried out two different experiments. The first examined metal uptake under a single, ecologically-relevant elevation of each metal (30 ppb Cu and 100 ppb Zn), and the second examined the relationships between varying levels of the metals (i.e., 15, 39, 60, 120, 240, and 480 ppb Cu, and 50, 100, 200, 300, 500, and 600 ppb Zn). Both experiments were designed to contrast the uptake of the metals in isolation (i.e., when only one metal concentration was elevated) and in combination (i.e., when both metals’ concentrations were elevated). Following three days of exposure to the elevated metal concentrations, we collected and analyzed the M. pyrifera tissues using inductively coupled plasma atomic emissions spectroscopy. Our results indicated that M. pyrifera bioaccumulated Cu in all treatments where Cu concentrations in the seawater were elevated, regardless of whether Zn concentrations were also elevated. Similarly, M. pyrifera bioaccumulated Zn in treatments where seawater Zn concentrations were elevated, but this occurred only when we increased Zn alone, and not when we simultaneously increased Cu concentrations. This suggests that elevated Cu concentrations inhibit Zn uptake, but not vice versa. Following this, our second experiment examined the relationships among varying seawater Cu and Zn concentrations and their bioaccumulation by M. pyrifera. Here, our results indicated that, as their concentrations in the seawater rise, Cu and Zn uptake by M. pyrifera tissue also rises. As with the first experiment, the presence of elevated Zn in the water did not appear to affect Cu uptake at any concentration examined. However, although it was not statistically significant, we observed that the presence of elevated Cu in seawater appeared to trend toward inhibiting Zn uptake, especially at higher levels of the metals. This study suggests that M. pyrifera may be useful as a bio-indicator species for monitoring heavy metal pollution in coastal environments.
-
Bioactive peptides and carbohydrates are sourced from a myriad of plant, animal and insects and have huge potential for use as food ingredients and pharmaceuticals. However, downstream processing bottlenecks hinder the potential use of these natural bioactive compounds and add cost to production processes. This review discusses the health benefits and bioactivities associated with peptides and carbohydrates of natural origin and downstream processing methodologies and novel processes which may be used to overcome these.
-
Seaweed is more than the wrap that keeps rice together in sushi. Seaweed biomass is already used for a wide range of other products in food, including stabilising agents. Biorefineries with seaweed as feedstock are attracting worldwide interest and include low-volume, high value- added products and vice versa. Scientific research on bioactive compounds in seaweed usually takes place on just a few species and compounds. This paper reviews world- wide research on bioactive compounds, mainly of nine genera or species of seaweed, which are also available in European temperate Atlantic waters, i.e. Laminaria sp., Fucus sp., Ascophyllum nodosum, Chondrus crispus, Porphyra sp., Ulva sp., Sargassum sp., Gracilaria sp. and Palmaria palmata. In addition, Undaria pinnatifida is included in this review as this is globally one of the most commonly produced, investigated and available species. Fewer examples of other species abundant worldwide have also been included. This review will supply fundamental information for biorefineries in Atlantic Europe using seaweed as feedstock. Preliminary selection of one or several candidate seaweed species will be possible based on the summary tables and previous research described in this review. This applies either to the choice of high value- added bioactive products to be exploited in an available species or to the choice of seaweed species when a bioactive compound is desired. Data are presented in tables with species, effect and test organism (if present) with examples of uses to enhance comparisons. In addition, scientific experiments performed on seaweed used as animal feed are presented, and EU, US and Japanese legislation on functional foods is reviewed.
-
Macroalgae or seaweed are relative un-explored and promising sources of novel molecules for the food industry including peptides and carbohydrates for their use as functional foods and nutraceuticals. Several algae-derived bioactive compounds have shown a wide range of biological activities both in vitro and in vivo, i.e. anti- hypertensive and antioxidant, that are strongly associated with the chemical structure of the peptides or car- bohydrates. Multiple improvements in the purification and analytical tools to characterize these compounds have been reported in recent years, aiming to gain further insight into the complexity of different molecular structures of bioactive peptides and carbohydrates. This paper discusses the variable composition of algae and the opportunities of the use of this biomass to obtain novel functional bioactive peptides and carbohydrates for functional food applications. The main biological activities of the discovered bioactive peptides and carbohy- drates together with the analytical procedures used to purify and characterize multiple compounds are also discussed.
-
Most marine macroalgae such as red seaweeds are potential alternative sources of useful bioactive compounds. Beside serving as food source, recent studies have shown that red seaweeds are rich sources of bioactive poly- saccharides. Red seaweed polysaccharides (RSPs) have various physiological and biological activities, which allow them to be used as immunomodulators, anti-obesity agents, and prebiotic ingredients. Lack of summary information and human clinical trials on the various polysaccharides from red seaweeds, however limits industrial-scale utilization of RSPs in functional foods. This review summarizes recent information on the ap- proaches used for RSPs extraction and purification, mechanistic investigations of their biological activities, and related molecular principles behind their purported ability to prevent diseases. The information here also pro- vides a theoretical foundation for further research into the structure and mechanism of action of RSPs and their potential applications in functional foods.
Pages
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.