"Adelaide, Dec. 1959." / Includes bibliographical references. / 1 v. (various pagings) : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The studies included in this thesis have been carried out since 1946 in the Department of Botany, University of Adelaide. The 25 papers, reprints from various journals, have been grouped in two sections; firstly those on intertidal ecology; secondly taxonomic studies (in order of publication). One paper on a freshwater Charophyte is also included. / Thesis (D.Sc.)--University of Adelaide, Dept. of Botany, 1959

Thesis (M.E.S.)--The Evergreen State College, 2007. / Title from title screen (viewed 1/24/2008). Includes bibliographical references.

Seaweeds are organisms which live in oceans and seas. They have ability to perform photosynthesis and feed many species of aquatic organisms. Macroalgae, which can be divided by characteristic colors in: Red algae (Phylum Rhodopyta), Green algae (Phylum Chlorophyta) and Brown algae (Class Phaeophyceae). Seaweeds are used for centuries by Asians as an important part of their diet, and also as source of compounds to Pharmaceutical and Cosmetic industries. The Brazilian Northeastern has a large coastal area; it possesses several forms of marine organisms especially for being in a Tropical hot water zone. Based on the importance of macroalgae, a chemical study was conducted using five species of algae (Bryothamnion seaforthii; Colpomenia sinuosa; Dictyosphaeria versluysii, Digenea simplex and Galaxaura rugosa) to prepare methanolic extracts and sequential fractions. 72 substances were identified using the GC-MS technique under the following operation conditions: helium as the carrier gas; 1.52 mL/min flow rate; oven temperature 60 º (25 ºC/min 300 ºC, heating rate); Splitless; injected volume 1 μL; solvent cutting 3 minutes. The mass spectra were obtained in the same equipment by electron impact ionization (EI) at 70 eV; and the ion source was maintained at 300 ° C. Hexadecanoic acid, in all fractions; 1-isopropyl-1,3,4-trimethyl-cyclohexane, 1,4-diisopropyl-cyclohexane and isopentyl decanoate, first identified in seaweeds; several esters, hydrocarbons and fatty acids can be mentioned as identified substances. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Alga é uma forma de vida que vive em oceanos e mares e possui a capacidade de realizar fotossíntese e servir de alimento e/ou abrigo para muitas espécies de organismos aquáticos. As macroalgas, que podem ser divididas pela cor característica que possuem, em algas vermelhas (Filo Rhodophyta), verdes (Filo Chlorophyta) e pardas (Classe Phaeophyceae), são utilizadas pelos orientais como parte importante de sua alimentação há vários séculos, além de utilizá-las como fonte de produtos farmacêuticos e da indústria de cosméticos. O nordeste brasileiro possui uma vasta área litorânea e costeira sendo rico em diversas formas de vida marinha, principalmente por estar em uma zona tropical de águas quentes. Com base na importância destas macroalgas, foi realizado um estudo químico de cinco espécies de algas, Bryothamnion seaforthii, Colpomenia sinuosa, Dictyospharia versluysii, Digenea simplex e Galaxaura rugosa, através de extratos metanólicos e frações. A técnica de cromatografia gasosa acoplada à espectroscopia de massas foi utilizada com as seguintes condições de operação: hélio como gás de arraste; velocidade do fluxo, 1,52 mL/min; a temperatura inicial do forno foi 60 ºC, com uma taxa de aquecimento de 25 ºC/min até 300 ºC; “Splitless”, como modo de injeção; 1 μL de volume injetado; e corte do solvente em 3 minutos. O tempo total de corrida foi 25 minutos. Os espectros de massas foram obtidos no mesmo equipamento, através de ionização por impacto de elétrons (EI) de 70 eV; e a fonte de íons foi mantida a 300 ºC. Desse modo foram identificadas 72 substâncias, dentre as quais podem ser citadas: ácido hexadecanoico, presente em todas as frações; os hidrocarbonetos 1-isopropil-1,3,4-trimetilcicloexano, 1,4-di-isopropilcicloexano e decanoato de isopentila, identificados pela primeira vez em algas; além de diversos ésteres, hidrocarbonetos e ácidos graxos.

Nya ideer, ny teknik och nya fibrer, möjligheterna är oändliga. Det krävs att den textila industrin förändras för att stoppa de farliga miljöutsläpp som sker idag. Bomull är ett av de mest använda och populära material på grund av dess egenskaper. Trots den stora utveckling som har skett, är miljövänlig bomull fortfarande ett icke hållbart material. Ny forskning har visat att alger kan bearbetas och bilda, tack vare sin cellulosa, ett textilt material. Denna studie syftar till att ta reda på huruvida textilt material baserat på algers cellulosa och bomull skiljer sig åt i dess egenskaper. Undersökningen innefattar också en miljömässig analys som presenterar om ett materiellt byte från bomull till alger är önskvärt. Resultatet har tagits fram tack vare en litteraturstudie samt en mailintervju med ett forskningsföretag som arbetar med att framställa textila material baserat på algers cellulosa. Det har tydligt framgått att framställningen av ett textilt material baserat på algens cellulosa är en mer miljövänlig process än att tillverka textilt material av bomull. Resultatet har också visat att det finns en del gemensamma egenskaper mellan materialen men även egenskaper som skiljer dem åt. Studien har tydligt visat att alger kan vara en del av framtidens fibrer, dock krävs det fortsatt forskning inom området för att det verkligen ska bli ett material att räkna med. / New ideas, new technologies and new fibers, the possibilities are endless. It is necessary that the textile industry change to stop the hazardous environmental emissions that are currently taking place. Cotton is one of the most widely used and popular material because of its characteristics. Despite the great developments that have taken place for more environmentally friendly cotton, it is still an unsustainable material. New research has shown that algae can be processed and formed thanks to its cellulose, into a textile material. This study aims to find out whether textile materials based on algae cellulose and cotton differ in its properties. The survey also contains an environmental analysis that presents whether a material change from cotton to algae is desirable. The result has been produced thanks to a literature study and an interview with a research company that works with producing textile material based on algae cellulose. It has been cleared that producing a textile material based on algae cellulose is a more environmentally friendly process than making textile materials from cotton. The result has also shown that there are some common properties between the materials, but also properties that distinguish them. The study has clearly shown that algae can be a part of the future fibers. However, continued research in the area is needed for it to really become a material to count on.

Call number: LD2668 .T4 1984 L43 / Master of Science

Doctor of Philosophy / Department of Biology / Walter K. Dodds / Streams exist in a state of dynamic equilibrium with frequent floods and drought. The frequency and intensity of stream disturbances are projected to increase with greater water withdrawal for agriculture and biofuel production, watershed development, and altered climate. Changes in the hydrologic regime may alter stream ecosystems. I studied how stream communities return after disturbances and how nutrients, consumers, and substrata heterogeneity influence recovery trajectories. Large consumers were excluded from pools following a severe drought to assess how community structure and function returned in their absence. Large consumers reduced algal biomass, primary productivity, and nutrient uptake rates, and delayed macroinvertebrate recolonization. However, grazer effects were temporary and their influence weakened after five weeks. In a second experiment, I assessed the relative influence of grazer density and nutrient loadings on algal recovery from flood. Nutrients had a stronger effect on recovery than grazers, but the strength of each varied temporally. Grazer control decreased and nutrient control increased over time. A third experiment addressed the physical properties of stream substrata on algal development. The relationship among algal accumulation and substrata surface topography was assessed by growing algae on substrata with varying orientation and roughness. Total algal biomass decreased on surfaces with angles > 45 degrees, and peaked at an intermediate roughness (pit depth of [similar to]17 [Mu]m). Rougher surfaces collected more tightly attached (grazer resistant) forms and less loosely attached (grazer susceptible) forms. Individual algal forms responded differently to grazing pressure, nutrient availability, and surface features. I developed a method using Fourier-transform infrared microspectroscopy to measure single-cell physiological responses in benthic algae. Nutrients and consumers were strong regulators of ecosystem succession following disturbance, but nutrient influence was stronger. The influence of nutrients and consumers were context dependent, and changed over the course of recovery. Rougher surfaces increase algal growth and shifted algal assemblages to more grazer resistant forms, which may decrease the influence of large consumers on stream function. Altering the severity and frequency of disturbances can change the trajectory of stream recovery and ultimately change community composition and stream metabolic activity, which may alter ecosystem services such as water purification and recreation.

Brown algae have been the focus of metal ecotoxicology research for over 60 years, mainly because of their high metal accumulation capacity and reputed resistance. Now that Ectocarpus siliculosus has been positioned as a model for the study of brown algae, and that the genome has been recently sequenced and annotated, new lines of research have been made possible on these ecologically and economically important organisms, including the field of ecotoxicology. Several strains of E. siliculosus have been collected and isolated from locations around the world, thus providing the opportunity to study inter-population differences in their responses to environmental stress. This investigation can be split into three main sections. In the first part Cu exposure experiments were carried out under laboratory conditions using three strains of E. siliculosus: Es524 from a Cu polluted location in Chile, REP10-11 from a metal polluted (including Cu) location in England and LIA4A from a pristine site in Scotland. Strains were exposed for 10 d to concentrations ranging between 0 and 2.4 μM Cu. We measured different parameters: relative growth rates; metal accumulation (extracellular and intracellular); phytochelatins and the expression of related enzymes; oxidative stress responses as manifested in lipid peroxidation and levels of H2O2, and levels of pigments; levels of antioxidants glutathione and ascorbate (in reduced and oxidised forms), and phenolic compounds; and the activity of the antioxidant enzymes superoxide dismutase, catalase, and ascorbate peroxidise. Strain Es524 was the most efficient in counteracting the effects of Cu stress as manifested by a combination of Cu exclusion production of metal chelators, upregulation of oxidative enzymes, and strong antioxidant metabolism. REP10-11 also showed effective Cu defences, especially related to glutathione-ascorbate interactions. LIA4A was the least tolerant strain, with metabolic defences significantly less effective against Cu exposure. In part two a novel transplantation experiment was developed to compare responses in the field with those obtained in the laboratory. The study was carried out at a metal polluted and a low-impacted site in central Chile using strain Es524 (as in the laboratory experiments) and Es147, isolated from a low metal-polluted site in Chile. From the biomass, we conducted similar measurements of Reactive Oxygen Metabolism (ROM) as for the laboratory experiments described in the first part. In agreement with the laboratory experiments, strain Es524 displayed a higher resistance to metal stress. Because they behaved similarly between strains, the best suggested biomarker candidates for future assessments are metal accumulation, glutathione and ascorbate in reduced and oxidised forms, phenolic compounds, and the activity of superoxide dismutase. The method is simple, widely applicable in temperate environments, cost-effective, and provides a reliable representation of metal bioavailability in the environment. In the final part of the study a novel technique for the co-extraction of RNA and DNA, using a high pH Tris-HCl buffer, from small amounts of biomass of different strains of E. siliculosus was successfully developed. The extraction of nucleic acids from brown algae is considered to be difficult and the product is of poor quality due to the high concentrations of interfering secondary metabolites such as phenolics and polysaccharides. The protocol devised here provided high yields of pure RNA and DNA that are suitable for molecular analyses. This investigation provides new insights on metal stress metabolism in brown algae, and demonstrates that metal resistance is dependent on inherited defences developed over a long history of exposure. Furthermore, the good agreement between the results obtained in the laboratory with those from the field study confirms that the responses expressed under controlled laboratory conditions are representative of stress metabolism of E. siliculosus under natural conditions.

Brown algae are important primary producers and habitat formers in coastal environments and are believed to have evolved multicellularity independently of the other eukaryotes. The phaeoviruses that infect them form a stable lysogenic relationship with their host via genome integration, but have only been extensively studied in two genera: Ectocarpus and Feldmannia. In this study I aim to improve our understanding of the genetic diversity, host range and distribution of phaeoviruses. Sequencing and phylogenetic analysis of amplified fragments of three core phaeoviral genes (encoding major capsid protein (MCP), DNA polymerase and superfamily III helicase) of phaeovirus infected algae confirmed the suspected phaeoviral identity of viruses infecting E. fasciculatus, F. simplex, Pilayella littoralis, Myriotrichia clavaeformis and Hincksia hincksiae. Furthermore, this approach revealed multiple virus sequence variants within individual strains, and moreover that the variants formed two distinct subgroups. Subgroup A was highly conserved and observed in multiple algal genera, whereas subgroup B was much more diverse, but only found in Feldmannia species. Transcriptome sequencing of an actively infected F. irregularis strain revealed polymorphisms within key viral genes, suggesting that multiple variants were indeed active within this strain. High resolution melt curve (HRM) technology was used to develop a high throughput screening method for detecting phaeoviral MCP as a proxy for detection of phaeoviruses. This technique was also able to assign 88% of those detected to one of the subgroups, based on their differing melting temperature distributions. This was then applied to 1034 Ectocarpus isolates collected from around Europe and South America, and in accordance with previous studies of phaeoviral infection, 43-79% of strains contain virus sequence (depending on species). 17% of the isolates tested even contained sequence from both subgroups. 82 Laminariales strains, close relatives of the Ectocarpales, were also screened because they comprise commercially important kelp species but are not known to be infected by viruses. 10-17% of these tested positive for phaeoviral MCP, which when sequenced formed a separate group within the phaeoviruses. This finding could have a major impact on the kelp farming industry if the viruses are found to affect reproduction as happens in the Ectocarpales. The discovery of two subgroups is contrary to current beliefs that the phaeoviruses are a single monophyletic group, and that each species of alga has its own phaeovirus, casting doubt on the usefulness of the current convention of naming each phaeovirus after its host. It appears that the subgroup B viruses have begun to evolve away from the stable, K-selected subgroup A viruses towards a more r- type strategy with higher mutation and diversification. This study has identified potential mechanisms that may influence this shift, including mutations in a region of the DNA polymerase known to negatively affect DNA replication fidelity, combined with an active integrase and lack of a proofreading exonuclease, along with the observed infection of individuals with both phaeovirusal subgroups. The resulting mutations and recombinations could lead to the diversity observed here, and may provide a suitable model for the study of other emergent virus infections.

The work in this thesis is an extension of a large study carried out by this college at Rothamsted Experimental Station (J. Featherstone-Witty, Ph.D thesis, 1974; with Keay, and Froggatt in press) and was aimed at scaling down the fieldwork to lysimeter investigations in order to elucidate the true value of algal inoculation as a replacement for synthetic fertilizers. Two lysimeters (each measuring 5m. x 3m.) were constructed above ground on concrete rafts with a built in facility to collect drainage water from the four quarters of each lysimeter. Both units were filled with calcareous soil (pH. 8). Each unit was divided into 4 treatments and sown to spring wheat. Previous indications were that this variety would benefit more from algal release of nitrogen than winter wheat because of a later maturation, and hence greater likelihood of the ears receiving nitrogen released from algal cells during late summer. A continuous record was kept of variations in soil, crop and drainage water nitrogen together with surface nitrogen fixation measurements (using the acetylene reduction technique), so that estimates of the efficiency of algal inoculation, to increase soil-N levels, could be made. Laboratory studies have suggested nitrogen fixation occurs only in soils low in nitrogen (less than about 4ppm) and algal cells apparently release very little extracellular nitrogen when grown on solid surfaces. These low levels of nitrogen would not support crop yields equivalent to those achieved by the application of synthetic fertilizers. Results from the two year lysimeter study suggest no improvement in crop yield for the algal inoculated treatments, compared with the controls, though total crop nitrogen, for the algal treatments was approximately 7% higher than the fertilizer treatments and 60% higher than the mean value for the two controls; ear nitrogen was as much as 46% higher than the controls. Algal inoculation, together with herbicide application, proved the best treatment, improving both crop dry weight and nitrogen composition significantly.

Microalgae synthesize and store large volumes of lipids (potentially over 25% of dry weight) which could provide a renewable source of biodiesel. Traditional extraction techniques often produce poor lipid yields particularly from microalgae with robust cell walls. This project investigated the role of power ultrasound as a cell disruption step in lipid extraction from four microalgal species. Nile Red staining was used to assess the time when ultrasound induced increased membrane permeability in each species and lipids were extracted using an ultrasound assisted Bligh and Dyer extraction method. A 20 kHz probe system (40% amplitude, 0.086 W/cm3) caused increased lipid recovery from dry biomass in all cases; D. salina (no cell wall) from 15 to 22.5% of dry biomass after 1 minute (26% when stressed with 35 g/L NaCl). C. concordia (thin cell wall) from 7.5 to 10.5% of dry biomass after 2 minutes (27% with 25% nitrogen reduction in growth media). N. oculata (thick cell wall) from 6.5 to 10% of dry biomass after 16 minutes (31.5% when stressed with 30 g/L NaCl). The stressed cultures yield could be improved to 35% when ultrasound was combined with S070 beating beads. Chlorella sp. (thick cell wall) from 6.3 to 8.7% of dry biomass, after 16 minutes (44% was achieved when harvested at day 9 instead of 15). A Dual Frequency Reactor (16 and 20 kHz, 0.01 W/cm3) flow system with S070 beads demonstrated that high lipid extraction yields could be achieved on a larger level with N. oculata. After 4:48 minutes sonication 24% lipid recovery was achieved. This system could theoretically increase daily microalgal oil production from 3.96 to 5.76 L per day when compared to conventional techniques, at an extra production cost of only 2.9 p/litre (1.5% increase). D. salina, N. oculata and C. concordia resumed normal growth following sonication at 20 kHz after 1-20 days (8 minutes treatment for D. salina, 60 minutes treatment for N. oculata and 16 minutes treatment for C. concordia). It was found that the supernatant of sonicated D. salina and C. concordia when added to established cultures were able to boost their growth.