This investigation has determined the presence of biological nitrogen fixation in two reservoirs in the southwestern United States: Lake Arlington and Lake Ray Hubbard. Subsequent tests have gathered baseline data on the effects of various biological, chemical, and physical parameters on in situ nitrogen fixation in these reservoirs. Of specific importance is the relationship between nitrogen fixation arid occasional blooms of blue-green algae which produce such problems as testes and odors in these water-supply impoundments.

Made available in DSpace on 2014-06-11T19:30:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-06-16Bitstream added on 2014-06-13T20:40:56Z : No. of bitstreams: 1 peres_ck_dr_rcla.pdf: 2904346 bytes, checksum: 27131e4815a7863f30631e2bf2fe155e (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Algas verdes são organismos presentes em todo o mundo, ocorrendo em uma grande amplitude de condições ecológicas. Em ambientes lóticos, elas são importantes tanto para a produção primária quanto para a criação e manutenção de habitats para outros organismos. Neste contexto, o presente estudo teve como objetivo abordar a taxonomia, distribuição ambiental e considerações biogeográficas das algas verdes macroscópicas de ambientes lóticos localizados em Unidades de Conservação (UC) na região Sul do Brasil. Para tanto, foram amostradas 10 UC´s dos quatro principais biomas desta região, totalizando 105 riachos. Na abordagem taxonômica foram tratadas 16 espécies pertencentes às ordens Chaetophorales, Cladophorales, Klebsormidiales, Microsporales e Ulotrichales, além de três espécies de algas verdes coloniais. Uma espécie do gênero Basicladia foi considerada como novo registro para a ciência e Cladophora sterrocladia foi registrada pela primeira vez no Brasil. Na abordagem teórica foram discutidos os aspectos reprodutivos das famílias Oedogoniaceae e Zygnemataceae e a sua implicação em estudos taxonômicos e ecológicos. Uma hipótese relacionada à poliploidia foi sugerida para explicar a baixa frequência de ocorrência de espécimes portadores de estruturas reprodutivas em ambientes lóticos. A partir dos materiais destas duas famílias encontrados nos riachos do Sul do Brasil foi conduzida uma separação em 12 morfotipos baseados essencialmente no diâmetro celular. Estes morfotipos foram testados quanto a sua relação com as variáveis ambientais. Por fim, considerando o aspecto ecológico foi abordada a distribuição ambiental das algas verdes macroscópicas de riachos nos principais biomas da região Sul do Brasil, levando em consideração os padrões de riqueza, abundância e composição de espécies e a sua relação com a distância geográfica e as... / Green algae are organisms found throughout the world, occurring in a wide range of ecological conditions. In lotic environments, green algae are important both for primary production and for the creation and maintaining of habitats for other organisms. In this context, this study aimed to addressing the taxonomy, ecological distribution and biogeographical considerations of lotic macroscopic green algae in conservation units (UC) in Southern Brazil. For this purpose, 10 UC´s in four principal biomes of this region were sampled, amounting 105 streams. In the taxonomic approach were treated 16 species belonging to the orders Chaetophorales, Cladophorales, Klebsormidiales, Microsporales and Ulotrichales, and three species of colonial green algae. One species of the genus Basicladia was considered as a new record to the science and Cladophora sterrocladia was first recorded in Brazil. In the theoretical approach were discussed the reproductive aspects of Oedogoniaceae and Zygnemataceae families and their implication in the taxonomic and ecological studies. One hypothesis related to polyploidy was suggested to explain the low frequency of specimens bearing reproductive structures in lotic environments. Based on the materials found in southern Brazil was made a division into 12 morphotypes based essentially on cell diameter. These morphotypes were tested for their relationship with environmental variables. Finally, the ecological aspect addressed the environmental distribution of macroscopic green algae from streams of the main biomes of Southern Brazil, taking into account the richness, abundance and species composition and their relation to geographic distance and the environment variables. The results showed that the presence or absence of the group was essentially related to shading and, to a lesser degree, to pH and current velocity of the sampling segment. Once occurring in a given ... (Complete abstract click electronic access below)

Syftet med denna studie var att undersöka vilka effekter luftföroreringar har på lavar och grönalger som växer på lindar, genom att jämföra lavfloran i urban miljö och i landsbygdsmiljö. Mer specifikt var syftet att utreda hur avstånd till närmaste väg, trafikintensitet och trädets exponerade respektive icke-exponerade sida gentemot en väg påverkar lavfloran i urban miljö. 18 utvalda lavarter samt grönalger eftersöktes på 86 lindar i urban miljö och 37 i landsbygdsmiljö inom Norrköpings kommun. Resultaten visade att artantalet, samt förekomsten och täckningsgraden för flertalet lavar var större i landsbygdsmiljö jämfört med urban miljö. Kortare avstånd till närmaste väg och hög trafikintensitet hade negativ effekt på flertalet lavar. I båda fallen visades det motsatta för grönalger. Det fanns ingen skillnad i förekomster av lavar om de exponerades utåt mot vägen eller bort från vägen. / The aim of this study was to investigate which effects air pollution has on epiphytic lichens and green algae in urban and rural environment, respectively.  More specifically, the aim was to investigate the effects on the lichen flora of distance to the nearest road, traffic volume and to compare the effect of tree sides exposed and not exposed to roads in the urban environment. 18 selected lichen selected species and green algae as a taxonomic group where searched on 86 lime trees in urban and 37 in rural environments in the Norrköping municipality. The species number was higher and the majority of the lichens occurred more often and showed a higher cover on trees in rural areas compared to trees in the urban environment. Shorter distance to the nearest road and high traffic volume had a negative impact on the majority of lichens. In both cases the opposite was shown for the green algal group. The lichens occurred equally often on the sides of the trees that were exposed to the road as on the sides that were not exposed to the road.

No description available.

The potential of the unicellular green algae Chlorella vulgaris and Scenedesmus obliquus and the filamentous green algae Cladophora glomerata and Hydrodictyon reticulatum as protein sources in Oreochromis niloticus and Tilapia zillii diets was investigated. When O. niloticus and T. zillii were fed with fresh C. vulgaris and S. obliquus, a high percentage of the ingested algae was found to be undigested. Heat treatment of the algae at 40°, 60°, 80° and 100°C produced increased growth and protein utilizations in the fishes compared to those fed the untreated algae. Feeding C. vulgaris treated at 100°C for 30 minutes and S. obliquus treated at 100°C for 15 minutes was found to have produced the best growth responses in O. niloticus and T. zillii. C. glomerata meal and H. reticulatum meal were each fed separately as fishmeal substitutes in pelleted rations formulated to contain 30% protein with varying proportions of this supplied by the fishmeal and the algal meal. A diet containing 25% protein supplied by the algal meal alone was also fed. When 5% of the fishmeal protein was replaced with algal protein (both C. glomerata and H. reticulatum) and fed to T. zillii, the growth and protein utilization values recorded were superior to those obtained for the control 30% fishmeal protein diet. Higher levels of algal protein substitution were, however, found to produce poorer growth and protein utilization values in both fish species. Diets containing only algal protein (both C. glomerata and H. reticulatum) produced the poorest growth responses in both fish species. Hydrodictyon reticulatum was found to be limiting in methionine and histidine. Supplementation of these essential amino acids produced improved growth in both O. niloticus and T. zillii. It was concluded from these studies that the green algae evaluated may be suitable partial dietary protein sources for tilapias.

Thesis (Doctoral)--Universiteit van Amsterdam, 1982.

The literature on the effects of phytohormone on algae is clouded with contradictory reports. Reports have been published which substantiate and deny the effects of phytohormones in enhancing the growth and developmental processes in algae. The overall aim of this study was to investigate the response, if any, of the phytohormones indole-3-acetic acid (IAA), gibberellic acid A3 (GA) and kinetin on the physiology of the green alga, Scenedesmus quadricauda. Results obtained for the uptake of 14^C-IAA an(j l4C-kinetin by Scenedesmus strongly support the presumption that the alga does not absorb the hormones. The retention of the phytohormones by the alga is due to adsorption, and is independent of hormone concentration. Most of the label was adsorbed by the outer pectic layers of the cell wall.

The transduction of stress signals in plants is known to involve complex hysiological responses. In D. salina a range of stresses results in hyperaccumulation of ft-carotene and an understanding of stress responses in this organism has important biotechnological implications. In this thesis an attempt was made to elucidate the physiological components involved and establish a role for pH in response to high light stress. In order to achieve this the effect of high light stress on photosynthesis and cell productivity was measured. Results showed that photosynthetic carbon assimilation, oxygen evolution and cellular productivity was initially inhibited by exposure to high light intensities, but this inhibition was transient and was overcome by a rapid increase in all three parameters. The response of the carbon pool intermediates was also investigated. It was shown that on exposure to high light ft-carotene declined but then showed a rapid increase after about 4 hours of exposure. It was also demonstrated that the initial loss of ft-carotene was due to loss of this pigment from the photosynthetic pigment bed and that the hyper-accumulation of ft-carotene was due to accumulation of ft-carotene in lipoidal globules located in the chloroplast stroma. It was further demonstrated that there was mass movement of carbon in the xanthophyll cycle shortly after exposure to high light. This was characterized by the de-epoxidation of violaxanthin to antheraxanthin with a further de-epoxidation to zeaxanthin, thereby decreasing the epoxidation state of the cycle. Furthermore, it was shown that there was relocation of carbon from violaxanthin to the plant growth regulator abscisic acid. It was also shown for the first time in D. salina that the production of ft-carotene and operation of the epoxidation state of the xanthophyll cycle has a periodicity which is established after exposure to successive cycles of a light regime. Chlorophyll fluorescence was used together with well established ammonia stress responses to acquire a general overview of energy dissipation from the photosynthetic pigment bed. In conjunction with an understanding of xanthophyll cycle operation during exposure to high light stress it has been possible to establish a relationship between chlorophyll florescence, xanthophyll cycle operation and intracellular pH. It was also shown using chlorophyll fluorescence that after 4 hour exposure to high light a maximum fluorescence peak could no longer be induced indicating a transition at about this point from a state of reversibility to commitment of the full stress response. Nuclear magnetic resonance was used to follow intracellular pH fluxes during exposure to high light. A novel technique was developed for studying photosynthetically active organisms in the dark using nuclear magnetic resonance. These results showed that on exposure to high light stress there is rapid acidification of the chloroplast stroma and to a lesser degree of the acidic vacuole. The pH of these compartments is re-established after about 4 hours which is co-incident with the onset of fl-carotene hyper-accumulation and the loss of the induction of the chlorophyll fluorescence peak indicating an intimate relationship for fl-carotene, chlorophyll fluorescence, xanthophyll cycle operation and pH. The results from this study allow for the proposal of a general physiological stress transduction response mechanism for D. salina which is common for a range of different stresses and where intracellular pH plays a central role.

Submitted by Natalie Mendes (nataliermendes@gmail.com) on 2015-11-12T23:29:45Z No. of bitstreams: 1 Ramos 2013 - Algas verdes cocoides (Chlorophyta) de duas ?reas do pantanal dos Marimbus (Baiano e.pdf: 8915844 bytes, checksum: 4608fb4b95cdad6269d11095980552c4 (MD5) / Made available in DSpace on 2015-11-12T23:29:45Z (GMT). No. of bitstreams: 1 Ramos 2013 - Algas verdes cocoides (Chlorophyta) de duas ?reas do pantanal dos Marimbus (Baiano e.pdf: 8915844 bytes, checksum: 4608fb4b95cdad6269d11095980552c4 (MD5) Previous issue date: 2013-03-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This study aimed at surveying the coccoid green algae flora of two areas of the Pantanal dos Marimbus (Baiano and Remanso), EPA Marimbus Iraquara, located in the Chapada Diamantina, Bahia, Brazil. Material was obtained from 120 samples collected during the dry (April, June and August 2011) and in the rainy season (October and December 2011, and February 2012). During this study 121 taxa of coccoid green algae were identified, described, illustrated and commented, which are distributed in two classes, four orders and 46 genera, 109 species, three varieties typical and seven other does not typical of their respective species, and two taxonomic formae. 17 (14%) of the total of taxa identified are pioneer citations for Brazil, 51 taxa (42%) for the Northeast Region of Brazil, and 19 taxa (15,7%) for the Bahia State. Most taxa recorded were classified in the Sphaeropleales (76%), followed by Chlorellales (17%), Trebouxiales (3%) and Chlorococcales ?sensu stricto? (2%), while the taxa considered ?incertaesedis? were represented by 3% of the total taxa identified. Among the taxa studied in both areas, 14 were exclusive of the rainy period and only seven of the dry one, while 100 taxa were common to both climatic periods. The species richness was clearly higher in the Marimbus do Baiano with 115 taxa (95%), while the Marimbus do Remanso showed 99 taxa (82.5%). Of the 121 taxa studied, 22 were unique to the Marimbus do Baiano and six to the Marimbus do Remanso. According to the S?rensen similarity index (86.9%), the similarity between the Marimbus do Baiano and do Remanso was considered high. Most taxa inventoried (48%) was classified as rare on Pantanal Marimbus, followed by infrequent (42%), frequent (7%) and very frequent (3%). Considering that about 90% of the taxa found are listed first for the Bahia State, we strongly suggest continuing studies of biodiversity of inland water algae to increase knowledge of phycoflora in Bahia State and Brazil. / O presente estudo ? o levantamento flor?stico das algas verdes coc?ides ocorrentes em duas ?reas do Pantanal dos Marimbus (Baiano e Remanso), APA Marimbus Iraquara, localizada na Chapada Diamantina, Bahia, Brasil. Os materiais estudados provieram de 120 amostras coletadas no per?odo seco (abril, junho e agosto de 2011) e no chuvoso (outubro e dezembro de 2011 e fevereiro de 2012). Foram identificados, descritos, ilustrados e comentados 121 t?xons de algas verdes coc?ides, distribu?dos em duas classes, quatro ordens e 46 g?neros, 109 esp?cies, tr?s variedades t?picas e sete n?o t?picas de suas respectivas esp?cies e duas formas taxon?micas. Do total de t?xons inventariados, 17 t?xons (14%) s?o cita??es pioneiras para o Brasil, 51 t?xons (42%) para a Regi?o Nordeste do Brasil e 19 t?xons (15,7%) para o Estado da Bahia. A maior riqueza de t?xons foi registrada para a ordem Sphaeropleales (76%), seguida de Chlorellales (17%), Trebouxiales (3%) e Chlorococcales ?sensu strictu? (2%), enquanto que os t?xons considerados ?incertae sedis? foram representados por 3% do total. Dentre os t?xons estudados nas duas ?reas, 14 foram exclusivos do per?odo de chuva e apenas sete do per?odo de seca, enquanto que 100 t?xons foram comuns a ambos os per?odos clim?ticos. A riqueza espec?fica foi claramente maior no Marimbus do Baiano, com 115 t?xons (95%), enquanto que o Marimbus do Remanso apresentou 99 t?xons (82,5%). Dos 121 t?xons inventariados, 22 t?xons foram exclusivos do Marimbus do Baiano e seis do Marimbus do Remanso. De acordo com o ?ndice de Similaridade de S?rensen (86,9%), a similaridade entre os Marimbus do Baiano e do Remanso foi elevada. A maior parte dos t?xons inventariados (48%) foi classificada como de ocorr?ncia rara no Pantanal dos Marimbus, seguido de pouco frequente (42%), frequente (7%) e muito frequente (3%). Considerando que cerca de 90% dos t?xons encontrados s?o referidos pela primeira vez para o Estado da Bahia, sugere-se a continuidade dos estudos de biodiversidade de algas de ?guas continentais para ampliar o conhecimento da ficofl?rula na Bahia e no Brasil.

Algal blooms are a common occurrence in water bodies of all shapes and sizes throughout the United States and countries around the world. The State of Florida is no exception to this phenomenon. Cyanobacteria, or blue-green algae, have proven to be of special concern due to its proliferation and potential to produce toxins that are harmful to humans, livestock and wildlife. A casual drive along the roads and in the neighborhoods of central Florida will confirm algal conditions in many areas. The potential for exposure to harmful and possibly fatal toxins associated with these algal blooms are becoming more evident as urban development progresses. Detailed studies have been previously performed for large lakes and rivers in the State of Florida, but no studies have been performed regarding stormwater ponds. Since stormwater ponds in residential neighborhoods are a common source for irrigation, research in this area is warranted due to the potential health effects associated with Cyanobacteria. This research was conducted to determine if Cyanobacteria does exist in stormwater ponds and to what extent. Cyanobacteria were found to be in stormwater ponds of various sizes, locations and watersheds in the central Florida area. Even though the algae and its associated toxins were encountered in the stormwater ponds evaluated for this study, the levels detected were much lower than the values discovered in previous studies performed in the larger lakes and rivers around the State.