Digital library

  • An integrated use of Macroalgae as bioproducts source and biosorbent for environmental applications

    Marine macroalgae are available in large quantities in many regions of the world and have been widely investigated as potential biosorbents for the removal of metals in wastewaters. However, few studies have been published on the biosorption of metals with seaweeds waste after the extraction of bioactive compounds.

    This dissertation presents the study about: 1) the valorisation of macroalgae biomass based on the biorefinery concept giving rise to added-value byproducts like polyphenols and polysaccharides, and 2) the use of the produced waste to remove Cu(II) from contaminated wastewaters.

    Chemical characterization of the two seaweeds studied, Ascophyllum nodosum and Ulva rigida, was performed. A.nodosum presented a higher percentage of ashes (13.8 ± 0.1 %) than U.rigida (10.9 ± 0.2 %). Regarding the percentage of polysaccharides, A. nodosum presented a lower percentage (45 ± 2 %) than U. rigida (48.7 ± 0.1 %). About the polyphenolic content, A. nodosum presented a higher value (0.95 mg GAE g-1) than U.rigida (0.33 mg GAE g-1).

    FTIR analyses of Ascophyllum nodosum, before and after Cu(II) biosorption, identified some of the main functional groups that play a key role in metal biosorption: carboxyl functional group – COOH and alcohol functional group - OH. FTIR analyses of Ascophyllum nodosum were performed before and after extraction of polyphenols, indicating that the lack of this bioactive compounds reduced the hydroxyl stretches.

    Preliminary biosorption tests for Cu(II) removal by Ascophyllum nodosum before and after extraction of polyphenols, present best results with A. nodosum virgin at pH values of 4 and 5. The adsorbed amount values obtained were in a range between 2.13- 2.25 mg g-1.

    The biosorption kinetics was found to be fast, with more than 50% of Cu(II) maximum adsorption equilibrium capacity attained within 15 minutes and equilibrium reached after 30 minutes. This kinetic data was fitted to pseudo first-order and pseudo second-order models.

    Author(s): JOÃO ALBANO DA CUNHA OLIVEIRA

  • An Integrated System to Produce Food, Fuel, Energy in Hawai'i

    A PDF of a demonstration project on "An Integrated System to Produce Food, Fuel, Energy in Hawai'i".

    Author(s): Bob Shleser

  • An improved chromosome preparation from male gametophyte of Laminaria japonica (Heterokontophyta)

    An improved method for the preparation of chromosomes from the male gametophyte of the alga Laminaria japonica Aresch. was described. The male gametophyte was pretreated with pDB (p-dich1orobenzene) and 8- hydroxyquinoline in order to clear cell wall and soften cytoplasm. The samples were treated by mordant iron alum [FeNH4 (S04h ·6H20] followed by staining with haemotoxylin. Well-spread and highly stained chromosomes were observed without precipitation. The chromosome number of male gametophyte of L. japonica was estimated to be 31.

    Author(s): Song Dong Shen, Ji Xun Dai, Li Ran Zhou

  • An Illustrated Review on Cultivation and Life History of Agronomically Important Seaplants

    Seaplants (a better alternative to the misnomer “Seaweeds”), by all means, are “future plants”; they have been projected as the future viand for ever-increasing human populations, viable and sustainable source for biofuel without disturbing global food scenario, as potential candidates for carbon capture and sequestration that is considered as a practical remedy for global warming, and they have a number of pharmaceutical, industrial and biotechnological applications. However, information on its cultivation methods or life history remain obscure to a majority of marine botanists. While life histories of seaweeds have traditionally been an exotic topic for specialists-language of which is ciphered with scientific jargons incomprehensible to general scientific audience, its agronomy had been a trade secret for coastal communities in East Asian countries, especially Japan, the Philippines and Indonesia. In this up-to-date illustrated review, current scientific understanding on the life-histories of agronomically pertinent seaweeds are presented in a fashion akin to popular science journalism with an overview of major coastal and offshore seaweed mariculture techniques, presented with the aid of clear-tounderstand illustrations. Also discussed in this report are recent advances in the algal natural products; including uses in hydrocolloid and pharmaceutical industries, Integrated Multi Trophic Aquaculture, energy production, environmental impacts of the seafarming and its counter measures, before concluding with an overview of future research avenues.

    Author(s): Felix Bast

  • An examination of the population genetics of Laminaria and other brown algae in the Laminariales using starch gel electrophoresis

    While some investigators have attempted to use isozyme electrophoresis to gain information on the genetics of brown algae, most have reported unsatisfactory results. Through exhaustive screening and modification of sample preparation techniques, gel and tray buffers systems, plus staining recipes, we have developed procedures that consistently provide scorable bands for over 20 enzyme systems in several laminarian algae. We have used our procedures to examine geographically diverse populations of Laminaria saccharina and L. longicruris, as well as L. digitata, L. groenlandica, Agarum cribrosum, Alaria esculenta, Chorda tomentosa, and Macrocystis pyrifera. Overall, these kelp species seem to have an extremely low degree of enzyme solymorphism, both within and between populations. While some rare alleles occurred in several enzyme systems, only 3–5 loci were found to be polymorphic. Our results are consistent with the few reported studies that have used molecular genetic techniques to look at the intraspecific variability of laminarian algae. We suggest that at the species level the Laminariales, and perhaps other groups of brown algae, are genetically extremely conservative as compared to other divisions of plants. We further suggest that isozyme electrophoresis provides a quick and useful tool for algal population genetic studies.

    Author(s): M. A. Miller, Charles Yarish, R. T. Eckert, A. C. Mathieson, H. P. Baldwin, Bruce P Allen, Chris Neefus

  • An Ethnobotanical Study of Some Edible Hawaiian Seaweeds

    In late 1972 the authors were given a superb opportunity to interview Hawaiians from Kauai to Hawaii to learn their uses of edible seaweed (limu). We contacted persons who had been recommended to us by former Kamehameha Schools classmates and friends, and took with us specimens of 15 common seaweeds, some of which had Hawaiian limu names known to us and some which were unknown to us. Speaking in Hawaiian to the older informants, we sought three kinds of information: 1) the Hawaiian common names used for a particular kind of seaweed; 2) a discussion of these common names and their meaning, and 3) uses of these and other algae by Hawaiians. We were pleased to learn that "country folk" still use many seaweeds for food, and that the older Hawaiians retain a large amount of information and folklore about these plants. 

    Author(s): Eleanor Horswill Williamson, Isabella Aiona Abbott

  • An essay on the effects of the fucus helminthocorton upon cancer, more especially in the stage denominated occult; with a concise enquiry into the origin and nature of the disease, and the probable way in which the dispersion of these tumours is effected

    Together with observations on the various modes of practice of regular practitioners, and others in the present day, enabling the reader at one view to become acquainted with every method now pursuing for the curse of this malady. 

    Author(s): William Farr

  • An Engineered Microbial Platform for Direct Biofuel Production from Brown Macroalgae

    Prospecting macroalgae (seaweeds) as feedstocks for bioconversion into biofuels and commodity chemical compounds is limited primarily by the availability of tractable microorganisms that can metabolize alginate polysaccharides. Here, we present the discovery of a 36-kilo-base pair DNA fragment from Vibrio splendidus encoding enzymes for alginate transport and metabolism. The genomic integration of this ensemble, together with an engineered system for extracellular alginate depolymerization, generated a microbial platform that can simultaneously degrade, uptake, and metabolize alginate. When further engineered for ethanol synthesis, this platform enables bioethanol production directly from macroalgae via a consolidated process, achieving a titer of 4.7% volume/volume and a yield of 0.281 weight ethanol/weight dry macroalgae (equivalent to ~80% of the maximum theoretical yield from the sugar composition in macroalgae).

    Author(s): Adam J. Wargacki , Effendi Leonard, Maung Nyan Win, Drew D. Regitsky, Christine Nicole S. Santos, Peter B. Kim, Susan R. Cooper, Ryan M. Raisner, Asael Herman, Alicia B. Sivitz, Arun Lakshmanaswamy, Yuki Kashiyama, David Baker, Yasuo Yoshikuni

  • An Engineered Microbial Platform for Direct Biofual Production from Brown Macroalgae

    Prospecting macroalgae (seaweeds) as feedstocks for bioconversion into biofuels and commodity chemical compounds is limited primarily by the availability of tractable microorganisms that can metabolize alginate polysaccharides. Here, we present the discovery of a 36–kilo–base pair DNA fragment from Vibrio splendidus encoding enzymes for alginate transport and metabolism.

    The genomic integration of this ensemble, together with an engineered system for extracellular alginate depolymerization, generated a microbial platform that can simultaneously degrade, uptake, and metabolize alginate. When further engineered for ethanol synthesis, this platform enables bioethanol production directly from macroalgae via a consolidated process, achieving a titer of 4.7% volume/volume and a yield of 0.281 weight ethanol/weight dry macroalgae (equivalent to ~80% of the maximum theoretical yield from the sugar composition in macroalgae).

    Author(s): Adam J. Wargacki, Effendi Leonard, Maung Nyan Win, Drew D. Regitsky, Christine Nicole S. Santos, Peter B. Kim, Susan R. Cooper, Ryan M. Raisner, Asael Herman, Alicia B. Sivitz, Arun Lakshmanaswamy, Yuki Kashiyama, David Baker, Yasuo Yoshikuni

  • An ecosystem model for optimising production in integrated multitrophic aquaculture systems

    Integrated multitrophic aquaculture (IMTA) aims to be an ecologically balanced aquaculture practice that co-cultures species from multiple trophic levels to optimise the recycling of farm waste as a food resource. It provides an opportunity for product diversification and an increase in economic return if managed at the optimal stocking densities for each co-cultured species. A generic IMTA ecosystem model, incorporating dynamic energy budgets for a number of co-culture species from different trophic levels was developed to design IMTA farms for optimisation of multispecies productivity. It is based on the trophic similarity in the ecophysiological behaviour of cultured organisms to describe the uptake and use of energy. This approach can accommodate different species within a trophic group and is transferable to IMTA operations based on finfish–shellfish-detritivore-primary producer systems. Model simulations were firstly performed considering the monoculture of mussels and finfish, each “farm” interacting with the natural variability of the local environment. The next step was running the IMTA model with the co-culture groups added in: one run was with finfish as the key species in co-culture with seaweed and sea cucumbers and the other with mussels as the key culture species in association with seaweed and sea cucumbers. Scenario simulations show that conversion from monoculture to IMTA would considerably reduce waste products and increase farm productivity. Although the development of IMTA practices will depend on acceptable levels of waste products, feasibility and profitability of culture operations, the IMTA model provides a research tool for designing IMTA practices and to understand species interactions and predict productivity of IMTA farms. The refinement of the model and its power to predict multispecies productivity depends on emerging data from trial and commercial sea-based IMTA operations.

    Author(s): Jeffrey S. Ren , Jeanie Stenton-Dozey, David R. Plew, Jianguang Fang, Mark Gall

Pages