As cianobactérias são microrganismos fotossintetizantes oxigênicos com ampla plasticidade metabólica e estrutural, que apresentam potencial biotecnológico para exploração na biossorção de metais pesados e biodegradação de poluentes orgânicos. Devido as suas fortes interações com cátions e ao contínuo suprimento de biomassa barata,as cianobactérias podem ser candidatas promissoras à biossorventes para remoção de metais e radionuclídeos. Dessa maneira, numa tentativa de encontrar uma cianobactéria com esse perfil para remover 226Ra de uma mina de urânio desativada da Unidade de Tratamento de Minérios (UTM) pertencente às Indústrias Nucleares do Brasil (INB), Caldas, MG, doze linhagens de cianobactérias foram isoladas desse ambiente. Essas linhagens foram morfologicamente caracterizadas como Aphanothece sp. CENA75, Rhabdoderma sp. CENA114, Synechococcus cf. lividus CENA79, Aphanocapsa cf. holsatica CENA80, Geitlerinema acutissimum CENA85, Pseudanabaena galeata CENA84, Pseudanabaena sp. CENA81, Leptolyngbya cf. tenerrima CENA76, Leptolyngbya sp. CENA83, Phormidium formosum CENA86, Phormidium violaceum CENA82 e Nostoc sp. CENA87. A análise molecular dos isolados, baseada em seqüências quase completas do gene RNAr 16S (1325 pb), estava de acordo com a análise morfológica, com exceção das linhagens Rhabdoderma sp. CENA114 e Phormidium violaceum CENA82. As seqüências de RNAr 16S dessas duas linhagens mostraram valores baixos de identidades (<92%) com seqüências do GenBank, o que pode representar novas espécies de cianobactérias. Altas percentagens de identidades (>96%) das seqüências do gene de RNAr 16S foram encontradas entre as linhagens restantes e as do GenBank. A árvore filogenética construída usando o método ?Neighbour Joining? mostrou que as linhagens unicelulares das ordens Chroococcales e as filamentosas da Oscillatoriales eram polifiléticas, conforme já relatado. A distribuição e abundância da população de cianobactérias nos efluentes da UTMINB foram investigadas pelo método da contagem de células viáveis (número mais provável, NMP). O NMP mostrou uma população de cianobactérias variando de 4.0 x 100 to ?2.4 x 108 cells?mL-1. Os locais Cava da Mina, com pH médio de 3,88, e o sistema de tratamento da usina, com pH 8,0, mostraram os mais baixos e mais altos valores de NMP, respectivamente. Para identificar os isolados de cianobactérias prejudiciais, um teste imunológico (ELISA) foi realizado para detectar microcistinas, uma hepatotoxina que causa envenenamento em humanos. A produção de microcistinas foi detectada em três isolados, Pseudanabaena galeata CENA84, Pseudanabaena sp. CENA81 e Leptolyngbya cf tenerrima CENA76. Esse resultado é inédito, pois não há relatos dos gêneros Pseudanabaena e Leptolyngbya como produtores de microcistinas. / Cyanobacteria are oxygenic photosynthetic microorganisms with wide metabolic and structural plasticity, which have biotechnological potential for exploration in metals biosorption and organic pollutants biodegradation. Due to its strong interactions with cations and a reliable supply of cheap biomass, cyanobacteria may be a promising biosorbent candidate for removing metals and radionuclides. In this way, in an attempt to find a cyanobacteria with this profile to remove 226Ra from a deactivated uranium mine effluents of the Ores Treatment Unit (UTM) belonging to the Nuclear Industries of Brazil (INB), Caldas, MG, twelve cyanobacterial strains were isolated from this environment. These strains were characterized morphologically as Aphanothece sp. CENA75, Rhabdoderma sp. CENA114, Synechococcus cf. lividus CENA79, Aphanocapsa cf. holsatica CENA80, Geitlerinema acutissimum CENA85, Pseudanabaena galeata CENA84, Pseudanabaena sp. CENA81, Leptolyngbya cf. tenerrima CENA76, Leptolyngbya sp. CENA83, Phormidium formosum CENA86, Phormidium violaceum CENA82 and Nostoc sp. CENA87. The molecular analysis of the isolates, based on the sequences of nearly complete 16S rRNA gene (1325 bp), was in agreement with the morphological analysis, with exception of Rhabdoderma sp. CENA114 and Phormidium violaceum CENA82 strains. The 16S rRNA sequences of these two strains showed low identities scores (<92%) with sequences from GenBank, which may represent novel cyanobacterial species. High percentages of identities (>96%) of 16S rRNA gene sequences were found between the remaining strains and of the GenBank. The phylogenetic tree of 16S rRNA sequences constructed using Neighbour-Joining method showed that unicellular strains of the orders Chroococcales and filamentous Oscillatoriales were polyphyletic, as reported earlier. The distribution and abundance of cyanobacterial population in the effluents of UTMINB were investigated by viable cells counting (most probable number, MPN) method. The MPN showed a cyanobacterial population range from 4.0 x 100 to ?2.4 x 108 cells?mL-1. The locations of the Pit Mine with pH 3.88 and the Plant System Treatment with pH 8.0 showed the lowest and highest MPN values, respectively. To identify harmful cyanobacterial isolates, an immunological test (ELISA) was carried out to detect microcystins, a hepatotoxin which cause human poisoning. Microcystins production was found in three isolates, Pseudanabaena galeata CENA84, Pseudanabaena sp. CENA81 and Leptolyngbya cf. tenerrima CENA76. This is a novel result since there is no report for both genera, Pseudanabaena and Leptolyngbya, as microcystin producers. Based on the obtained results, the Aphanothece CENA75 strain found in all UTM-INB effluents sampled, including in the Pit Mine location, which has an acidic pH (average of 3.88) and high level of uranium (5.68 mg?L-1) and radium, was selected for the 226Ra biosorption assays. The experiments performed in pH 3.5 and 5.0 showed that dried biomass of Aphanothece CENA75 behaves as a weakly acid resin. The ratio (final concentration/initial concentration) of 226Ra adsorption after 135 min in pH 3.5 and 5.0 was 0.86 and 0.82, respectively. These results showed that the dried biomass of Aphanothece CENA75 adsorbed low amount of 226Ra in both studied pH values. However, the increase of the radionuclide retention in pH 5.0 suggests that more adsorption may occur in pH above of this value.

A microbiota intestinal humana desempenha papel essencial no organismo saudável, pois sintetiza vitaminas, influencia no desenvolvimento e maturação do sistema imune da mucosa intestinal, além de exercer importante função protetora, competindo por nutrientes e receptores com bactérias patogênicas. A colonização desta microbiota se inicia na criança recém-nascida e alcança estabilidade em torno do segundo ano de vida, com consequência para a saúde da criança e do adulto. As diferenças na composição da microbiota estão relacionadas a diferentes níveis de contaminação ambiental e de diferentes fatores endógenos. O objetivo do nosso estudo foi analisar a microbiota fecal de crianças com idade entre 2 dias a 1 ano de idade, que vivem em baixas condições socioeconômicas em São Paulo, Brasil. Foram coletadas amostras de fezes de crianças saudáveis, nos seguintes pontos pós-nascimento: 2º e 7º dias, 1 mês, 3 meses, 6 meses e 1 ano de vida. O DNA bacteriano foi extraído diretamente a partir das amostras de fezes e as bibliotecas 16S rRNA foram construídas utilizando 2 iniciadores bactéria-específicos. Os clones foram selecionados aleatoriamente, parcialmente sequenciados e analisados com base em bibliotecas de gene 16S rRNA. Os principais grupos filogenéticos identificados foram Escherichia, Clostridium, Streptococcus e Bacteroides, do 1º ao 30º dia de vida. A partir do 3º mês, Streptococcus e bactérias não cultiváveis, além do gênero Escherichia, ganharam relevância na microbiota. Estes dados, em conjunto com as informações nutricionais, intercorrências clínicas e ambientais, sugerem a influência da contaminação ambiental e interpessoal no aumento da complexidade na composição da microbiota fecal. Essa abordagem molecular permitiu a análise da microbiota fecal do grupo selecionado, encontrando perfil bacteriano diferente do que é descrito nos países desenvolvidos. / The human intestinal microbiota plays essential role in healthy body since it synthesizes vitamins, influences on the development and maturation of the immune system of the intestinal mucosa. Furthermore, it also plays an important protective function competing for nutrients and receptors with pathogenic bacteria. The colonization of this microbiota starts in the newborn child and achieves stability around the second year of life, with consequence for the health of children and adults. The differences in the microbiota composition are related to different levels of environmental contamination and different endogenous factors. The aim of our study was to analyze the fecal microbiota of children ranging from 2º days to 1º year old living in low socioeconomic status in São Paulo, Brazil. We collected fecal samples of healthy children at the following points after birth: 2º e 7º days, 1 month, 3 months, 6 months and one year of life. Bacterial DNA was extracted directly from stool samples, and the 16S rRNA libraries were made using 2 bacterium-specific primers. The clones were randomly selected, and partially sequenced and analyzed based on 16S rRNA libraries. The main phylogenetic groups identified were Escherichia, Clostridium, Streptococcus, Bacteroides ranging from the 1º to 30º days of life. From the third month Streptococcus and uncultured bacteria, and, besides, Escherichia gender gained relevance in the microbiota. These data together with nutritional information, environmental and clinical intercurrents suggest the influence of interpersonal and environmental contamination in the increase of complexity in fecal microbiota composition. This molecular approach allowed the fecal microbiota analysis. This bacterial profile is different from described in developed countries.

O objetivo do presente estudo foi avaliar o desempenho, saúde intestinal e metabolizabilidade de dietas para frangos de corte alimentados com o uso contínuo ou mudança brusca de diferentes rações à base de milho e sorgo moído ou inteiro. No Exp. 1 foi estudada a mudança no tipo de grão com as dietas: M100% (ração à base de milho); S100% (ração à base de sorgo); M:S50% (ração à base de 50% milho e 50% sorgo); PS-M (ração à base de sorgo na fase pré-inicial e milho nas demais fases); PM-S (ração à base de milho na fase pré-inicial e sorgo nas demais fases). No Exp. 2 foi estudada a mudança na forma do grão de sorgo: Sm100% (ração à base de sorgo moído); Si100% (ação à base de sorgo inteiro); PSm-Si (ração à base de sorgo moído na fase pré-inicial e inteiro nas demais fases) e PSi- Sm (ração à base de sorgo inteiro na fase pré-inicial e moído nas demais fases). Os experimentos foram conduzidos em um delineamento em blocos casualizados (blocos no tempo) para avaliar o desempenho e epitélio jejunal (r=8), microbiota intestinal (r=4) e metabolizabilidade das dietas (r=10). As mudanças entre milho e sorgo não alteraram o desempenho, epitélio jejunal nem a metabolizabilidade das rações, mas influenciaram a porcentagem de Clostridium, Weissella, Bacillus e Alkaliphilus no intestino delgado e Lactobacillus e Desulfotomaculum nos cecos. O uso de sorgo inteiro piorou o desempenho aos sete dias. Aos 40 dias, Sm100% e PSm-Si apresentaram desempenhos semelhantes, PSi-Sm apresentou menor ganho de peso, mas melhor conversão alimentar e Si100% apresentou o pior desempenho. Si100% e PSm-Si apresentaram aumento no peso relativo da moela e na metabolizabilidade das rações, assim como diminuição de Clostridium e aumento de bactérias das famílias Actinomycetales e Bacillales no intestino delgado, Si100% resultou em menor porcentagem de Alkaliphilus e Enterococcus que Sm100% nos cecos. Conclui-se que a melhor estratégia de uso do sorgo é a substituição total de milho por sorgo moído ao alojamento com posterior mudança para sorgo inteiro, pois não afeta o desempenho e epitélio jejunal das aves, melhora a metabolizabilidade das rações e potencializa a redução de Clostridium no intestino delgado de frangos de corte. / The aim of this study was to evaluate performance, intestinal health and metabolizability of diets in broilers fed different corn- or sorghum (ground or whole)- based diets, continuously or with abrupt change between the diets. Exp. 1 - Change in the type of grain: C100% (corn-based diet); S100% (sorghum-based diet); C:S50% (50% corn and 50% sorghum-based diet); PC-S (corn-based diet in pre-starter phase and sorghum-based diet in other phases); PS-C (sorghum-based diet in pre-starter phase and corn-based diet in other phases). Exp. 2 - Change in the form of sorghum grain: Gs100% (ground sorghum-based diet); Ws100% (whole sorghum-based diet); PGs-Ws (ground sorghum-based diet in pre-starter phase and whole sorghum-based diet in other phases); PWs-Gs (whole sorghum-based diet in pre-starter phase and ground sorghum-based diet in other phases). Experiments were conducted in a randomized block design for to evaluate performance and jejunal epithelium (r=8), intestinal microbiota (r=4) and metabolizabilty of diets (r=10). The changes between corn and sorghum did not affect performance, jejunal epithelium or metabolizability of the diets, but influenced the genera Clostridium, Weissella, Bacillus and Alkaliphilus in the small intestine, and Lactobacillus and Desulfotomaculum in the caecum. Whole sorghum resulted in decreased performance at seven days of age. At 40 days, Gs100% and PGs-Ws showed similar performance, PWs-Gs showed lower weight gain and the best feed conversion rate, and Ws100% showed the worst performance. Ws100% and PGs-Ws resulted in the biggest gizzard relative weight and the highest diet metabolizability values, as well as the lowest level of Clostridium and highest level of Actinomycetales and Bacillales in the small intestine. Ws100% showed lower level of Alkaliphilus and Enterococcus than Gs100% in the caecum. The best strategy to use sorghum in broilers diets is replacing 100% of corn for ground sorghum since the first day followed by change to whole sorghum, because this diet did not affect performance or jejunal epithelium, improved diet metabolizability values, and reduced Clostridium in the small intestine of broilers.

The main goal of this thesis was to design and implement a tool that would be able to classify the sequences of the 16S rRNA gene into taxonomic categories using the properties of the 16S rRNA gene. The created tool analyzes all input sequences simultaneously, which differs from common classification approaches, which classify input sequences individually. This tool relies on the fact that bacteria contain several copies of the 16S rRNA gene, which may differ in sequence. The main contribution of this work is design, implementation and evaluation of the capabilities of this tool. Experiments have shown that the proposed tool is able to identify the corresponding bacteria for smaller datasets and determine the correct ratios of their abundances. However, with larger datasets, the state space becomes very large and fragmented, which requires further improvements in order for it to search the state space in an efficient way.

ENGLISH : The use of different characteristics (the polyphasic approach) to describe bacterial taxa is a prerequisite for a stable classification. The taxonomy of root- and stem-nodulating rhizobia is in a state of transition. As more legumes are studied, new species and genera of rhizobia are described. It is important to study the indigenous South African rhizobia, as without them a complete rhizobial taxonomy is not possible. Furthermore, strains with superior nitrogen fixation abilities may be discovered. Indigenous strains better adapted to the harsh South African environment are possible candidates for commercial inoculants for cropped legumes.Only two local studies have been done on the diversity of the indigenous rhizobia. These studies revealed the diversity of rhizobia existing in the South African context. As part of a polyphasic approach used to identify and determine the diversity of the indigenous rhizobia, 16S rDNA sequencing analysis was performed on some selected rhizobial and putative rhizobial isolates. The aim of the study was to characterise and identify the indigenous isolates by 16S rDNA sequencing analysis and compare our data with those available in the GenBank database. Results showed that most of the indigenous isolates were slow-growers belonging to the genus Bradyrhizobium. Two isolates from supposedly non-nodulating legume genera (Cassia and Senna) were found to belong to the genus Bradyrhizobium. Some of the isolates were shown to belong to the genera Mesorhizobium, Rhizobium and Sinorhizobium. The identity of five isolates was not clear and further studies need to be performed to unequivocally determine their taxonomic position. Partial sequence analysis of 16S rDNA proved a valuable tool to characterise and identify the indigenous isolates. However, the method was unable to clearly distinguish between closely related species and strains. AFRIKAANS : 'n Stabiele klassifikasiesisteem vir die beskrywing van bakteriese taksa is slegs moontlik deur verskillende eienskappe (die poli-fasiese benadering) te gebruik. Die taksonomie van die wortel- en stamnodulerende rhizobiums verander gedurig. 'n Volledige rhizobiumtaksonomie is slegs moontlik indien die inheemse Suid-Afrikaanse rhizobiums bestudeer word. Geharde inheemse rasse met voortreflike stikstofbindende vermoens kan ontdek word. Hierdie rasse is kandidate vir kommersiele inokulums vir verboude peulplante. Net twee plaaslike studies is gedoen om die diversiteit van die inheemse rhizobiums te bepaal. Die studies het bewys dat die inheemse rhizobiums baie divers is. As deel van die polifasiese benadering om die diversiteit van die inheemse rhizobiums te identifiseer en te bepaal, is 16S rDNS volgordebepaling gedoen op uitgesoekte rhizobia en sogenaamde rhizobia isolate. Die doel van die studie was die karakterisering en identifisering van die inheemse isolate deur 16S rDNS volgordebepaling en die vergelyking van die data met die beskikbaar in die GenBank databasis. Die resultate wys dat die meeste inheemse isolate stadige groeiers is en dus behoort aan die genus Bradyrhizobium. Twee isolate vanaf sogenaamde nie-nodulerende peulplantgenusse (Cassia en Senna) behoort ook tot die genus Bradyrhizobium. Sommige isolate behoort tot die genusse Mesorhizobium, Rhizobium en Sinorhizobium. Die identiteit van vyf isolate was nie duidelik nie en verdere studies is nodig om hul taksonomiese posisie ondubbelsinnig te bepaal. Die gedeeltelike volgordebepaling van die 16S rDNS was 'n waardevolle hulpmiddel om die inheemse isolate mee te karakteriseer en te identifiseer, alhoewel die metode nie tussen nabyverwante spesies en rasse kon onderskei nie. Copyright / Dissertation (MSc (Microbiology))--University of Pretoria, 1999. / Microbiology and Plant Pathology / unrestricted

"Où peut-on trouver des microbes, et comment survivent-ils dans ces lieux ?" sont des questions essentielles afin de comprendre la vie sur Terre. Les populations bactériennes du sol sont connues pour jouer un rôle important dans les cycles biogéochimiques, l'entretien des sols, les effets climatiques et l'agriculture.Dans ce travail, j'ai utilisé la technique de pyroséquençage, via le produit d’une PCR d’ADNr 16S amplifiée extraite d’ADN totale, afin de révéler les populations bactériennes présentes dans quatre environnements inhabituels et oligotrophes différents:A. Les écosystèmes saumâtres sont largement distribués sur Terre et sont représentés par des systèmes aquifères salés et des sols salins. Nous avons examiné la composition bactérienne des sédiments des estuaires, sols saumâtres et des échantillons de sol sablonneux de la région de Camargue, échantillonnés pendant deux années consécutives. Les membres appartenant au phylum Proteobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Acidobacteria et Actinobactéries ont été trouvés principalement dans les sols et sédiments. Nous avons constaté que les membres de ces groupes bactériens étaient associés principalement à des bactéries halophiles, sulfatoréductrices (SRB), nitratoréductrices et coliformes, dont leurs proportions ont probablement été affectées par la salinité et leurs localisations géographiques.B. Les bactéries associées à la rhizosphère des plantes sont connues pour jouer un rôle essentiel dans les cycles biogéochimiques, la nutrition des plantes et la lutte biologique contre les maladies végétales. Nous avons examiné les populations bactériennes de la rhizosphère du riz (Oryza sativa) en fin de croissance dans la région de la Camargue en 2013 et 2014. Les populations bactériennes les plus abondantes se sont révélées être des membres appartenant au phylum Proteobacteria, Acidobacteria, Chloroflexi et Gemmatimonadetes. Les genres bactériens auxquels appartiennent ces différents phylums sont connus pour participer dans des processus biogéochimiques du sol, tel que la nitrification, la dénitrification, l'oxydation, ainsi que comme agents de control biologique. Les proportions bactériennes trouvées varient considérablement en fonction de leur localisation géographique et selon l’année d’échantillonnage.C. Nous avons examiné les sols de surface de "Padza de Dapani" situés sur l'île de Mayotte au large de la côte est de l'Afrique, car cette région n’est pas un vrai désert, mais y ressemble due à l’érosion du sol. Les sols de Mayotte sont acides, oligotrophes et minéralisées, et leur population bactérienne principale appartient aux phylums des Actinobactéries, Proteobacteria et Acidobacteria. Un fait intéressant, les membres des genres Acinetobacter, Arthrobacter, Burkholderia et Bacillus sont prédominants dans nos échantillons, comme observé dans des déserts (asiatiques) chauds et jouant probablement un rôle dans la minéralisation des sols, expliquant la désertification.D. Les régions arides de la Terre constituent > de 30% de la surface continentale et les sols oligotrophes sont soumis à des facteurs environnementaux difficiles tels que la faible pluviométrie moyenne annuelle, l'exposition aux UV et les grandes fluctuations de température. Nous avons examiné les populations bactériennes présentes dans la rhizosphère des plantes pionnières et les sols de surface du désert de Jizan d'Arabie Saoudite. Les phylums bactériens les plus abondants appartiennent aux groupes des Bacteroidetes, Proteobacteria et Firmicutes qui diffèrent entre la rhizosphère des plantes étudiées par rapport à la surface du sol, à l'exception de la plante "Panicum Turgidum" qui contient des proportions élevées (70%) des membres appartenant au genre Flavobacterium. / “What microbes are where, and how do they live there” is now an essential question to understand life on Earth, even when comparing seemingly similar ecosystems in different locations. Soil bacterial populations are known to play important roles in biogeochemical cycles, soil maintenance, climatic effects and agriculture. I used pyrosequencing of PCR amplified 16S rDNA from total extracted DNA in order to reveal the bacterial populations living in four different unusual and oligotrophic environments: A. Saline areas are widely distributed on Earth’s and are represented by both saline lakes and saline soils. We examined the bacterial composition of estuary sediments, brackish and sandy soil samples from the Camargue region (Rhône delta in southern France) sampled in two consecutive years. Members belonging to the Proteobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Acidobacteria and Actinobacteria phyla were found principally in saline sediment and soil samples. We found that members from these phyla were associated principally to halophilic bacteria, sulphate reducing bacteria (SRB), nitrate reducing bacteria and coliforms, and that their varying proportions were likely affected by salinity and geographical location. B. Bacterial populations associated with the rhizosphere of plants are known to play essential roles in biogeochemical cycles, plant nutrition and disease biocontrol. We examined the bacterial populations of the rhizosphere of rice (Oryza sativa) growing in the Camargue region in 2013 and 2014. The most abundant bacterial populations were found to be members belonging to the Proteobacteria, Acidobacteria, Chloroflexi and Gemmatimonadetes phyla. The genera members belong these phyla were found to participate in soil biogeochemical processes such as nitrification, denitrification, oxidation, as well as act as biocontrol agents. The bacterial populations were found to significantly vary by geographical location as well by year of collection. C. We examined the surface soils from “Padza de Dapani” on the island of Mayotte off the east coast of Africa, as this region is not a true (hot) desert, but resembles one due to extensive soil erosion. In the acidic, oligotrophic and mineralized soil samples from Mayotte, members of the Actinobacteria, Proteobacteria and Acidobacteria phyla dominated the bacterial populations. Interestingly, members of the genera Acinetobacter, Arthrobacter, Burkholderia and Bacillus were found to be predominant in our samples, as is also observed in hot (Asian) deserts and may play roles in soil mineral weathering, thus helping to understand desertification processes. D. Earth’s arid regions comprise >30% of the continental surface and the oligotrophic soils are subjected to harsh environmental factors such as low average annual rainfall, high UV exposure and large temperature fluctuations. We examined the bacterial populations present in the rhizosphere of pioneer plants and surface soils in the Jizan desert of Saudi Arabia. The most abundant bacterial phyla belonged to the Bacteroidetes, Proteobacteria and Firmicutes phyla that were different between the rhizosphere of plant versus these from surface sand, with the exception of the plant “Panicum Turgidum”, which contain in its rhizosphere high proportions (70%) of members belonging to the Flavobacterium genus.

Discoveries of new natural antibiotics are now relatively rare, therefore the construction of strains producing hybrid substances seems to be a very promising opportunity to gain new interesting biologically active compounds. This work is part of a larger project focused on the preparation of new biologically active substances derived from the antibiotic lincomycin. Lincomycin is composed of saccharide (MTL) and amino acid (propylhygric acid) moieties condensed by amide bond. Various modifications of amino acid moiety, especially of the side alkyl chain, are known to improve the antibiotic properties of final molecule. The bottleneck of biosynthesis of such modified compounds is the condensing enzyme NDL-synthetase, and especially its A-domain, which, similarly to nonribosomal peptide synthetases (NRPS), specifically recognizes and activates the amino acid precursor. In this work a set of degenerate primers for PCR searching of NRPS A-domains was proposed and the conditions of PCR reaction were optimized. In the first step a collection approximately 800 isolates of soil actinomycetes will serve as a source of genetic information for search of interesting NRPS A-domains, applicable for the construction of hybrid biosynthetic clusters. The isolates of this collection have been also characterized taxonomically...

O gênero Persephona Leach, 1817 é restrito a América e é constituído por dez espécies com ocorrência no Atlântico Ocidental e Pacífico Oriental, estando inserido na subfamília Ebaliinae, a qual não se encontra taxonomicamente bem estabelecida. Ao longo dos anos, este gênero foi alocado em diferentes subfamílias e sua classificação é mal definida. Além disso, existem chaves de identificação que não permitem a correta identificação das espécies dentro do gênero. Estas infomações são indicativos de uma forte necessidade de estudos enfocando Persephona, os quais podem fornecer uma melhor compreensão sobre a história evolutiva do gênero. Neste contexto, o presente estudo pretendeu realizar uma ampla revisão taxonômica do gênero Persephona, incluindo caracteres que possuem grande variabilidade dentro do gênero (número e tamanho dos espinhos, quelípodos, etc), caracteres tradicionalmente utilizados na diagnose das espécies, além de outros selecionados a partir do presente estudo (gonópodos, coloração, etc), além de incluir pela primeira vez para o gênero, análises de dados moleculares. Dois genes mitocondriais, o 16S rRNA e o Citocromo Oxidase I (COI) foram utilizados como marcadores. As análises morfológicas revelaram uma ausência de diferenças entre algumas espécies propostas para o gênero Persephona, as quais foram corroboradas pelas análises moleculares. Desta forma, são propostas modificações a respeito da taxonomia de Persephona: P. finneganae é um sinônimo júnior de P. lichtensteinii. O nome P. crinita é valido apenas para os espécimes de ocorrência no Golfo do México; os espécimes de P. mediterranea com ocorrência no Golfo do México, correspondem a P. aquilonaris e aqueles com ocorrência no Caribe e Atlântico Sul, correspondem a P. mediterranea e além do exposto, Iliacantha hancocki é um sinônimo júnior de P. subovata. / The genus Persephona Leach, 1817 is restricted to America and consists of ten species occurring in the Western Atlantic and Eastern Pacific. It belongs to the subfamily Ebaliinae, which is not taxonomically well established. Over the years, Persephona was placed in different subfamilies and its classification is still poorly defined. Also, existing identification keys do not allow a correct classification of the species within the genus. These informations are indicatives of a strong need of studies focusing on Persephona, which can provide a better understanding concerning its evolutionary history. In this context, the present study intends to undertake a broad taxonomic revision of the genus Persephona, including characters possessing great variability within the genus (number and size of the spines, cheliped, etc.), characters traditionally used in the diagnosis of the species, and others selected from the present study (gonopod, coloration, etc.), including for the first time for the genus, analyses of molecular data. As guides for the molecular analyses, two mitochondrial genes, the 16S rRNA and the Cytochrome Oxidase I (COI) were used as markers. The morphological analyses revealed an absence of differences among some species proposed for the genus Persephona, wich were corroborated by molecular and phylogenetic analysis. In this way, is propose modifications regarding Persephona taxonomy: P. finneganae is a junior synonym of P. lichtensteinii: the name P. crinita is valid only for specimens occurring in the Gulf of Mexico; the specimens of P. mediterranea with occurence in the Gulf of Mexico, correspond to P. aquilonaris and those with occurence in the Caribbean and South Atlantic correspond to P. mediterranea, moreover I. hancocki is a junior synonym of P. subovata.

O gênero Persephona Leach, 1817 é restrito a América e é constituído por dez espécies com ocorrência no Atlântico Ocidental e Pacífico Oriental, estando inserido na subfamília Ebaliinae, a qual não se encontra taxonomicamente bem estabelecida. Ao longo dos anos, este gênero foi alocado em diferentes subfamílias e sua classificação é mal definida. Além disso, existem chaves de identificação que não permitem a correta identificação das espécies dentro do gênero. Estas infomações são indicativos de uma forte necessidade de estudos enfocando Persephona, os quais podem fornecer uma melhor compreensão sobre a história evolutiva do gênero. Neste contexto, o presente estudo pretendeu realizar uma ampla revisão taxonômica do gênero Persephona, incluindo caracteres que possuem grande variabilidade dentro do gênero (número e tamanho dos espinhos, quelípodos, etc), caracteres tradicionalmente utilizados na diagnose das espécies, além de outros selecionados a partir do presente estudo (gonópodos, coloração, etc), além de incluir pela primeira vez para o gênero, análises de dados moleculares. Dois genes mitocondriais, o 16S rRNA e o Citocromo Oxidase I (COI) foram utilizados como marcadores. As análises morfológicas revelaram uma ausência de diferenças entre algumas espécies propostas para o gênero Persephona, as quais foram corroboradas pelas análises moleculares. Desta forma, são propostas modificações a respeito da taxonomia de Persephona: P. finneganae é um sinônimo júnior de P. lichtensteinii. O nome P. crinita é valido apenas para os espécimes de ocorrência no Golfo do México; os espécimes de P. mediterranea com ocorrência no Golfo do México, correspondem a P. aquilonaris e aqueles com ocorrência no Caribe e Atlântico Sul, correspondem a P. mediterranea e além do exposto, Iliacantha hancocki é um sinônimo júnior de P. subovata. / The genus Persephona Leach, 1817 is restricted to America and consists of ten species occurring in the Western Atlantic and Eastern Pacific. It belongs to the subfamily Ebaliinae, which is not taxonomically well established. Over the years, Persephona was placed in different subfamilies and its classification is still poorly defined. Also, existing identification keys do not allow a correct classification of the species within the genus. These informations are indicatives of a strong need of studies focusing on Persephona, which can provide a better understanding concerning its evolutionary history. In this context, the present study intends to undertake a broad taxonomic revision of the genus Persephona, including characters possessing great variability within the genus (number and size of the spines, cheliped, etc.), characters traditionally used in the diagnosis of the species, and others selected from the present study (gonopod, coloration, etc.), including for the first time for the genus, analyses of molecular data. As guides for the molecular analyses, two mitochondrial genes, the 16S rRNA and the Cytochrome Oxidase I (COI) were used as markers. The morphological analyses revealed an absence of differences among some species proposed for the genus Persephona, wich were corroborated by molecular and phylogenetic analysis. In this way, is propose modifications regarding Persephona taxonomy: P. finneganae is a junior synonym of P. lichtensteinii: the name P. crinita is valid only for specimens occurring in the Gulf of Mexico; the specimens of P. mediterranea with occurence in the Gulf of Mexico, correspond to P. aquilonaris and those with occurence in the Caribbean and South Atlantic correspond to P. mediterranea, moreover I. hancocki is a junior synonym of P. subovata.

Published Article / An artificial neural network (ANN) that is able to distinguish between Cheddar cheese produced with milk from mixed and single breed sources was designed. Samples of each batch (4 pure Ayrshire/4 mixed with no Ayrshire milk) were ripened for 92 days and analysed every 14 days. A novel ANN was designed and applied which, based only on Lactococcus lactis counts, provided an acceptable classification of the cheeses. The ANN consisted of a multi-layered network with supervised training arranged in an ordered hierarchy of layers, in which connections were allowed only between nodes in immediately adjacent layers.