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Seaweed biomass has been identified as a potential fermentation substrate for third generation biofuel processes due to its high carbohydrate content and its potential for mass cultivation without competing for agricultural land, fresh water and fertilisers. This thesis aimed to develop and advance existing processes to convert brown seaweeds into bioethanol. The main kelp species chosen as biomass candidates were Laminaria digitata, Laminaria hyperborea, Saccharina latissima and Alaria esculenta due to their abundance in Scottish waters and their identified potential for mariculturing. These kelp species were chemically characterised to identify seasonal variations, to recommend suitable seaweed candidates for bioethanol production and predict best harvest times. This has only been demonstrated before on one species - L. digitata. The chemical composition analyses were carried out over a 14 months sampling period, which focused on the storage carbohydrates laminarin and mannitol and the structural carbohydrates alginate, cellulose, fucoidan and xylose. In addition to carbohydrates the protein, nitrogen, carbon, polyphenol, ash and metal content was also profiled. Chemical profiling identified all four kelps as potential fermentation candidates, where maximum carbohydrate contents coincided with lowest ash and polyphenol content, usually seen in autumn. Biomass pre-treatment and saccharification are up-stream processes aimed at enhancing extraction of carbohydrates and converting those into fermentable substrates. Conversion of seaweed biomass into fermentation substrate evaluated acids and enzymes for seaweed pre-treatment and saccharification. Methodologies focused on optimising saccharification yields were developed to identify process critical parameters and develop methods for routine analysis of seaweed biomass. Results demonstrated that dilute acid hydrolysis was were less effective in releasing fermentable sugars, and also resulted in higher salinities compared to enzymatic hydrolysis using hemicellulosic and cellulosic enzymes, which were the preferred method of saccharification. All seaweeds in this thesis were assessed as fermentation substrates using the yeasts S. cerevisiae and P. angophorae, that principally ferment glucose or mannitol, respectively. Small-scale fermentation assays were developed for both yeasts to maximise ethanol yields and achieve process robustness. Both yeasts achieved a maximum ethanol yield of 0.17 g g-1 using Laminaria spp. On the basis of results, S. cerevisiae is recommended as the most useful yeast at this present point for ethanol fermentation from seaweed hydrolysates because of its tolerance to high salinity and ethanol concentrations. As salinity can negatively affect non-halotolerant enzymes, isolation of marine microorganisms was therefore carried out with the aim to highlight their enzymatic potential in seaweed saccharification. This was achieved through the isolation of two members of the genus Pseudoalteromonas, where saccharification yields using crude intracellular enzyme preparations exceeded those of dilute acids. In addition, the fermentative potential of microbial isolates as future ethanologenic strains was also evaluated. Understanding of the metabolic pathways is needed to fully assess the potential of those strains for genetic alteration. In conclusion, this thesis has demonstrated that up to ca. 20 g l-1 of ethanol can be produced from kelp species that grow on the west coast of Scotland. The procedure developed and used to produce ethanol requires further development, specifically the need for ethanol-fermenting microorganisms that can utilize mannitol and alginate; use of marine-adapted enzymes for saccharifiction; and the development of processes to achieve substrate concentration with reduced salinities. Comparison of theoretical ethanol yields from seaweed biomass with ethanol yields from terrestrial crops showed that the complete utilisation of all three major seaweed carbohydrates (laminarin, mannitol and alginate) from kelp species is needed for the process to be able to compete with 1st generation biofuel processes.

Made available in DSpace on 2016-01-13T13:27:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-11-24. Added 1 bitstream(s) on 2016-01-13T13:33:13Z : No. of bitstreams: 1 000856267.pdf: 2565945 bytes, checksum: 07754b874d035f18e023aeb27c324535 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As macroalgas lóticas têm sido consideradas, juntamente com perifíton, briófitas e macrófitas, um dos principais produtores primários de ambientes de riachos. Por essa razão, nas últimas décadas muitos trabalhos vêm sendo realizados na tentativa de entender-se a distribuição espaço-temporal desses organismos. A grande maioria desses trabalhos tem investigado exclusivamente os efeitos de variáveis ambientais sobre os padrões de distribuição ecológica das macroalgas de riachos. Entretanto, apenas a relação entre a ocorrência e distribuição desses organismos e as variações do ambiente tem demostrado ser pouco preditiva em relação ao estabelecimento e manutenção das macroalgas nestes ecossistemas. Assim, parece claro que, além do mosaico dinâmico de condições ambientais, outras forças que atuam sobre estes organismos devem ser consideradas na análise de suas distribuições ecológicas. Neste sentido, é possível imaginar que as interações bióticas, em pequena escala, que ocorrem entre os organismos que coexistem em um mesmo trecho de riacho também possam interferir de maneira significativa nas respostas ecológias desses organismos. As microalgas e macro-invertebrados herbívoros, por exemplo, são organismos que coexistem intimamente com as macroalgas e, portanto, devem possuir papel relevante na distribuição desses organismos no ambiente. De fato, alguns estudos têm sugerido que os fatores internos de uma comunidade parecem ser mais importantes para determinar as suas variações do que os fatores externos, pontuais ou sazonais, que atuam durante o período de colonização. Neste contexto, o presente estudo investigou as possíveis interações bióticas existentes entre as micro e macroalgas de riachos tropicais, através da condução de um estudo experimental. De forma mais específica, o primeiro objetivo foi avaliar a existência de competitição ou cooperação entre as algas bentônicas (micro e... / The stream macroalgae have been considered, along with periphyton, bryophytes and macrophytes, one of the main primary producers in streams environments. For this reason, in recent decades many studies have been performed to understand the spatiotemporal distribution of these organisms. Most of these studies have only investigated the effects of environmental variables on patterns of ecological distribution of macroalgae streams. However, only the relationship between the occurrence and distribution of these organisms and the changes in environment has been shown to be poorly predictive in relation to the establishment and maintenance of macroalgae in these ecosystems. Thus, it seems clear that, beyond the dynamic mosaic of environmental conditions, other forces acting on these organisms should be considered in the analysis of their ecological distributions. In this sense, it is possible to imagine that biotic interactions on a small scale, that occur between coexistent organisms in the same stream stretch can also significantly influence on the ecological responses of these organisms. Microalgae and herbivorous, for example, are organisms that coexist intimately with macroalgae and therefore must have a relevant role in the distribution of these organisms in the environment. In fact, some studies have suggested that the internal factors of community seem to be more important in determining their variations than external, occasional or seasonal factors that act during the period of colonization. In this context, the present study investigated the possible existing biotic interactions between micro and macroalgae in tropical streams, by conducting an experimental study. More specifically, the first objective was to evaluate the existence of competition or cooperation between benthic algae (micro and macroalgae) over a process of colonization on artificial substrates. In addition, we tried to correlate these interactions with the dynamic ... / FAPESP: 10/17563-0

abstract: Recognition of algae as a “Fit for Purpose” biomass and its potential as an energy and bio-product resource remains relatively obscure. This is due to the absence of tailored and unified production information necessary to overcome several barriers for commercial viability and environmental sustainability. The purpose of this research was to provide experimentally verifiable estimates for direct energy and water demand for the algal cultivation stage which yields algal biomass for biofuels and other bio-products. Algal biomass productivity was evaluated using different cultivation methods in conjunction with assessment for potential reduction in energy and water consumption for production of fuel and feed. Direct water and energy demands are the major focal sustainability metrics in hot and arid climates and are influenced by environmental and operational variables connected with selected algal cultivation technologies. Evaporation is a key component of direct water demand for algal cultivation and directly related to variations in temperature and relative humidity. Temperature control strategies relative to design and operational variables were necessary to mitigate overheating of the outdoor algae culture in panel photobioreactors and sub-optimal cultivation temperature in open pond raceways. Mixing in cultivation systems was a major component in direct energy demand that was provided by aeration in panel bioreactors and paddlewheels in open pond raceways. Management of aeration time to meet required biological interactions provides opportunities for reduced direct energy demand in panel photobioreactors. However, the potential for reduction in direct energy demand in raceway ponds is limited to hydraulics and head loss. Algal cultivation systems were reviewed for potential integration into dairy facilities in order to determine direct energy demand and nutrient requirements for algal biomass production for animal feed. The direct energy assessment was also evaluated for key components of related energy and design parameters for conventional raceway ponds and a gravity fed system. The results of this research provide a platform for selecting appropriate production scenarios with respect to resource use and to ensure a cost effective product with the least environmental burden. / Dissertation/Thesis / Doctoral Dissertation Design 2015

Detailed analyses of the lipid class and fatty acid composition were carried out for the marine microalgal species Nannoch/oropsis oculata (Droop) (CCAP strain no. 849/1) of the division Eustigmatophyceae (Hibberd). The alga was grown in batch and continuous culture using a novel culturing apparatus, the cage culture turbidostat, the construction of which is detailed in full. The total lipid extract yielded by the alga varied in a growth-phase dependent manner within the range 25 % to 80 % of the lyophilised cell mass. Of this between 40 % and 70 % was recovered as fatty acid methyl esters (FAME) upon transesterification. The total fatty acid composition of N. oculata consisted mainly of 16:0, 16:1 and 20:5(n-3), these three fatty acids often accounting for greater than 80 % of the total fatty acid mass. Between 9 % and 50 % of the mass of total FAME was accounted for by 20:5(n-3), the balance being accounted for by variations in the relative proportions of 16:0, 16:1, 18:1, 18:2 and 20:4. During periods of low cellular division rate, such as the lag- and stationary-phases, the proportion of polyunsaturated fatty acids (PUFA) (mainly 20:5(n-3» decreased. The total fatty acids became increasingly saturated as higher proportions of shorter chain length fatty acids accumulated, mainly in triacylglycerols (TAO). Increased cellular proportions of total lipid resulted from TAO accumulation which occurred on account of preferential partitioning of carbon into TAO biosynthesis whilst cellular division was suspended. The fatty acid composition of the TAO was more saturated at high synthesis rate and vice-versa at lower rates. The galactolipids, monogalactosyldiacylglycerol (MODO) and digalactosyldiacyl glycerol (DODO) were rich in 20:5(n-3) during exponential cell division containing up to 77 % and 53 % 20:5(n-3) respectively. Phosphatidylcholine (PC) was the only cl~s to contain significant proportions of CIS fatty acids during exponential growth, thus implicating its involvement in the acyl chain elongation reactions between the Cl6 and C20 fatty acids. Culture incubation temperature in the range 5 °C to 25°C did not influence the fatty acid composition of N. oculata. The effect of temperature upon culture dynamics at the lower culture incubation temperatures gave an apparent decrease in the PUFA content of the total fatty acid at a given point on the cultures growth curves. By expressing the data in tenns of culture doubling periods during the exponential-phases of growth it was found that temperature had no real effect upon fatty acid unsaturation or chain length. at either the total or the individual lipid class FAME level after the cells had passed through five doubling periods. Increasing the culture medium salinity from one quarter to one and a half times that of normal seawater decreased the un saturation and chain length of the fatty acids at both total and individual lipid class levels. The change resulted from the progressive accumulation of 18:1 and 18:2"at the expense of 20:5. Variation of salinity did not affect the dynamics of the cultures in the same respect as temperature in that a lag-phase was not observed on the cultures growth curves. However. such a phase was evident in the fatty acid profile of the cells in the period following inoculation. The 'effects of culture illumination intensity in the range 45 Jill m-2 sec-I to 170 Jill m 2 sec-! were examined under continuous culture conditions using the cage culture turbidostat Accumulation of saturated TAG by the cells at the higher illumination intensities gave an apparent decrease in the rate of PUFA biosynthesis. The polar lipid classes were found to be more highly unsaturated at higher illumination intensities. At lower illumination intensity TAG accumulation was reduced and the total fatty acid composition was accordingly more unsaturated. The fatty acid composition of the TAG component was more unsaturated but those of the polar lipid classes were less unsaturated than at higher illumination intensity. Increased illumination increased the degree of un saturation of the polar lipid cl~sses. Excess fixed carbon was partitioned into TAG biosynthesis. primarily as 16:0 and 16:1. The net accumulation of this lipid class even at high cell division rates resulted in a low overall unsaturation level. The effects of decreasing nitrate concentration in the range 1.0 mM N03 - to 0.001 mM N03 - had a similar basis to those of illumination in that the changes in the total fatty acid composition were largely governed by the rate of TAO accumulation. At high nitrate concentrations the cellular division rate was relatively high and the proportion of TAO in the total lipid extract was low. Consequently, both total and individual lipid classes contained high proportions of unsaturates, particularly 20:5(n-3). However, when the nitrate concentration was decreased, such that it began to limit the rate of cellular division, TAG accumulated Cursory analyses of the molecular species of the galactolipid classes, MODO and DODO, and phospholipid class PC are presented. The effects of environmental variables are discussed in tenns of the changes which may occur in the growth phase distribution of the cells in asynchronous culture, along with the concommitant changes in the lipid composition of the cells. The potential linkage of the elongation and desaturation reactions with both MODO and PC is also discussed briefly with reference to future research.

Placophora binderi can be described as an "obligate epiphyte" as it does not respond well to any culture conditions and is found growing only on other algae in the natural environment. This habit may have arisen as a response to the best available substrate in a harsh environment (Harlin 1971; Moss 1982). Any nutrient transfer which may occur between Placophora binderi and its basiphyte, usually various species of Codium, is probably by diffusion as rhizoids do not penetrate the basiphyte cells but simply lie between the Codium utricles providing better anchorage. A triphasic life history exists with isomorphic gametophyte, carposporophyte and tetrasporophyte generations. The male and female gametophytes are dioecious. This study confirms Scagel's (1953) observations for the development of the juvenile, mature and reproductive thallus. The juvenile develops as an erect polysiphonous thallus which produces a prostrate lobe as an adventitious branch from the basal segments. This prostrate lobe develops into the dorsiventrally flattened mature thallus. Reproductive structures are produced on erect branches which are initiated at the mature thallus margins. The gametophyte develops on evanescent trichoblasts produced on erect reproductive branches while the tetra sporophyte develops within these erect branches. The female gametophyte has a four-celled carpogonial branch with an auxiliary cell forming after fertilisation from the supporting cell. At the electron microscope level several vesicle types were seen in the reproductive organs. In the male, spermatial vesicles are produced which probably aid in release of the spermatia (Kugrens 1980). These are also visible under the light microscope. In carposporogenesis and tetrasporogenesis, three vesicle types are produced. Striated vesicles appear for a short while during the early stages and probably function as protein stores. Fibrillar vesicles are large and visible under the light microscope. These probably act as carbohydrate storage organelles (Triemer and Vasconcelos 1979; Kugrens and West 1973c; Tripodi 1971). Cored vesicles appear late in sporogenesis and probably aid in adhesion once the spores have settled (Chamberlain and Evans 1973; Wetherbee 1978). Carpospores follow the "serial release" type pattern observed in Polysiphonia (Boney 1978). Tetraspores are released singly via a rupture in the tetrasporangial wall as in Ceramium rubrum (Chamberlain and Evans 1973). Both carpospores and tetraspores germinate in the typical bi-polar Ceramium-type pattern described by Dixon (1973)

This study of the brown algal genus Laminaria Lamour consisted of (1) a critical review of the taxonomy and distribution of taxa of Laminaria occurring in the northeast Pacific, (2) a description of the life histories and growth patterns of long and short stipe forms of L. groenlandica and L. saccharina, (3) an evaluation of the roles of temperature, salinity, and water motion as possible determinants of local distributions of long and short stipe forms of L. groenlandica and L. saccharina, and (4) an evaluation of the roles of temperature, salinity, exposure, and submarine illumination in determining the vertical distribution of L. saccharina. These studies were made from 1961 to 1965. Ten species of Laminaria are recognized for the northeast Pacific: L. groenlandica Rosenv.; L. farlowii Setchell; L. saccharina (L.) Lamour.; L. setchellii Silva; L. dentigera Kjellman; L. longlpes Bory; L. sinclairii (Harvey ex Hooker f. et Harvey) Farlow, Anderson et_ Eaton; L. ephemera Setchell; L. yezoensis Miyabe; and L. complanata (Setchell et Gardner) Setchell. Laminaria cordata Dawson is considered conspecific with L. saccharina, L. personata Setchell and Gardner is regarded conspecific with L. yezoensis, and L. platymeris De la Pyl. (sensu Setchell and Gardner) is considered conspecific with L. groenlandica. Pour forms of L. groenlandica are recognized for the northeast Pacific. These forms are not considered as legitimate taxonomic entities but are distinguished merely to provide a means of facilitating discussion. The known habitat requirements for all ten species were broadened and the known distributions of all species, excepting L. groenlandica, were extended. Laminaria saccharina and L. groenlandica produced sori in the late spring and winter. New sporophytes of L. groenlandica appeared throughout the year, whereas those of L. saccharina appeared in late winter and early fall. Depending upon culture conditions, two morphologically distinct forms of gametophytes were produced by both species: large gametophytes were produced in conditions of high temperature and low salinity; and small gametophytes in conditions of low temperature and high salinity. Abnormal sporophytes were observed under conditions conducive to formation of large gametophytes. Patterns of growth for the blades of the two species were essentially the same.. The growth rate decreased with increase in distance from the blade base, and the position of greatest longitudinal growth coincided with the position of greatest lateral growth. The distributions of L. saccharina and the two forms of L. groenlandica about Vancouver Island were correlated with temperature, salinity, and water motion. The two forms of L. groenlandica were absent from areas of high temperature and low salinity; L. saccharina was absent from areas subjected to surf. These field conclusions were subjected to laboratory and field tests involving gametophytes and sporophytes of both species. The distributions of the two forms of L. groenlandica can be explained on the basis of temperature and salinity distributions. Both forms require low temperature and high salinity for survival. Laminaria saccharina has a wide range of tolerance to temperature and salinity. Surf appears to be the agent controlling the distribution of this species. The upper limits of L. saccharina, as observed in Burrard Inlet, are thought to-be directly related, to air temperature and insolation and indirectly related to tidal characteristics. The lower limits appear to reflect the compensation depth of this species. / Science, Faculty of / Botany, Department of / Graduate

Developmental studies were made on certain intertidal algal communities at three sites on Juan de Fuca Strait, B.C. The object was to describe the form and structure of these communities and to provide an interpretation that would account for the manner in which they occur. Periodic observations were made on communities developing on denuded rock surfaces and on in situ communities. By using the denuded-quadrat method, a method familiar to terrestrial plant ecologists, species-distribution indices of frequency and abundance were taken to quantitatively describe the stages of recolonization. Data relative to the developmental process, such as life span and period of reproduction of the species involved, were also gathered. The experimental data reveal a pattern of development that is consistent and predictable. Despite the presence of an orderly sequence of events, there is no evidence to indicate that this is an expression of ecological succession. The partial or even total elimination of a population is concluded not to be due to any changes in habitat originated by that population. Instead its elimination, partial or otherwise, is considered to be a consequence of the degree of establishment of the proceeding population. The successional phenomenon, which can be altered by seasonal populants, is related to the morphological nature of the colonizing species. Unicellular forms appear before filamentous ones, and filamentous forms appear before parenchymatous ones. Such a succession is interpreted as being indicative of the relative growth rates and life spans of the growth forms. The length of time in which a population occupies an area is determined by these factors. The presence or absence of growth space can he a main cause for local distributional patterns, especially for ephemeral species. The dynamic structure of the communities studied is attributed to species interaction involving three interrelated factors: (1) the morphology of the organisms; (2) the phenological nature of germination, growth, reproduction, and of spore or gamete release; and (3) the competition for space. / Science, Faculty of / Botany, Department of / Graduate

Appropriate sampling and experimental programs resulted in a qualitative and quantitative assessment of seaweed litter biomasses, decomposition rates and concomitant changes in nitrogen content; detritus biomass and decomposition rates; and faunal distribution patterns for the significant species within a successional seaweed community in the Strait of Georgia, British Columbia, Canada. A simulation model incorporating suitable data obtained from these sampling and experimental programs facilitated prediction of detritus formation rates, biomass, nitrogen content and the seasonal availability of detritus as a food resource for fauna. Soluble matter release rates from decomposing seaweed litter and its nitrogen content were also determined. Of the ca 43 taxa identified within the seaweed litter collections, Fucus distichvs L. (41%), Irldaea cordata (Turner) Bory (26%), Nereocystis 1uetkeana (Mertens) Postels and Ruprecht (27%), and Laminaria (4%) (L. saccharina (L.) Lamouroux and L. groenlandica Rosenvinge) accounted for more than 97% of total litter deposition. The mean peak summer biomass of all litter was ca 5 g ash-free dry weight (AFDW)/m² with this figure approaching zero during January and February. Litter distribution was patchy and there was sufficient evidence to conclude that most litter was retained, and underwent decomposition, in the immediate vicinity of its place of deposition. Litter decomposition experiments performed on the 10 most significant contributors to seaweed community structure indicated that decomposition of seaweed litter occurs rapidly compared to vascular plant litter. The time required for seaweed litter to disappear from 2 mm mesh litter bags ranged from six days, for the lamina of Nereocystis luetkeana, to ca 70 days, for Fucus distichus. Some similarity in decomposition rates was observed amongst species displaying taxonomic and/or morphologic affinities. Assessment of nitrogen content of decomposing seaweed litter revealed that nine of the 10 species assayed lost nitrogen less rapidly than total litter biomass. As determined by assaying microbial consumption of particulate material, the time required for detritus (particle size < 1 mm, dry) to fully decompose was short. Of the 10 species tested, Iridaea cordata detritus decomposed most rapidly at a rate of 5.7% per day while rates for Gigartina papillata (C. Agardh) J. Agardh, Laminaria groenlandica, Laminaria saccharina and Nereocystis luetkeana ranged from 2-4% per day. Data for the remaining species were less conclusive although all decomposed at rates less than one percent per day. Variation in specific decomposition rates was shown to be correlated with the structural composition of the detritus. Those species with a relatively small percentage of crude fibre as a component of their particulate fraction decomposed more rapidly than those species with a higher percentage of crude fibre. For the two most rapidly decomposing species, Iridaea cordata and Nereocystis luetkeana, a trend toward a more rapid decomposition rate as mean particle size decreased was evident. Natural detritus (particle size < 2 mm, wet) biomass accumulation within the study site peaked at ca 1.4 g AFDW/m² during the latter half of August 19 76. This value represents 1-5% of the quantity of detritus predicted to have been formed from seaweed litter alone and a lesser percentage of the total quantity of seaweed detritus formed. Exportation out of the seaweed zone is believed to be responsible for this discrepancy. The predicted rates of detritus formation and soluble matter release from decomposing seaweed litter peaked at ca 0.6 and 0.5 g AFDW/m²per day, respectively, in early September 1976 from a low near zero in February. In total, ca 56% of litter biomass formed detritus, the remainder being released as soluble matter. The mean nitrogen contents of the detritus formed and the soluble matter released were 2.48 ± 0.03% and 1.36 ± 0.03% of their dry weights, respectively. The annual contribution of seaweed litter biomass via detritus and soluble matter to local coastal waters is estimated to be in the range of 70-85 g C/m². Detritus formed from seaweed litter was determined to have a C:N ratio of 10-13:1, rendering it suitably nutritious for utilization by fauna as a food resource, however it could not be shown conclusively that the coincidence, en masse, of specific fauna and maximum detritus availability was a response to the availability of detritus as a food resource. The possibility of such a correlation is discussed with reference to two species of caprellids, Caprella alaskana Mayer and Metacaprella anomala Mayer, and the benthic gastropod Lacuna marmorata Dall. / Science, Faculty of / Botany, Department of / Graduate

No description available.