A afiliação genérica de Fischerella e Hapalosiphon é problemática devido à instabilidade dos caracteres morfológicos. Os gêneros Fischerella e Hapalosiphon são diferenciados pela presença de tricoma multisseriado e uni ou bisseriado, respectivamente. Porém, geneticamente esses caracteres não se mostraram diacríticos para diferenciar gêneros. Estudos moleculares de linhagens isoladas de ecossistemas brasileiros são escassos para Fischerella e inexistentes para Hapalosiphon. Neste estudo, oito linhagens de cianobactérias, pertencentes à família Hapalosiphonaceae, isoladas de água doce e solos brasileiros foram caracterizadas morfologicamente e geneticamente e analisadas para a produção de substâncias bioativas. As análises morfológicas identificaram cinco morfotípos de Fischerella (CENA19, CENA161, CENA212, CENA213, CENA214) e três de Hapalosiphon (CENA63, CENA71, CENA72). As análises filogenéticas do RNAr 16S usando neighbor-joining (NJ) e máxima verossimilhança (MV) colocaram todas as linhagens isoladas em um agrupamento com alto suporte (reamostragens de 99% NJ e MV) contendo membros da ordem Nostocales. Além disso, as linhagens de Fischerella selecionadas para o estudo agruparam-se em um clado interno com alto valor de reamostragem (100% NJ e 86% MV), com exceção da Fischerella CENA19. A posição dessa estirpe na árvore filogenética indica que necessita de revisão taxonômica. As linhagens de solo Hapalosiphon CENA71 e CENA72 também formaram um clado interno separado (99% NJ e 98% MV), mas a linhagem de água doce CENA63 foi colocada em um clado diferente (com valores de reamostragens de 99% NJ e MV), juntamente com linhagens do gênero Hapalosiphon e Westielopsis prolífica SAG 16.93, oriundas de solo. A comparação das análises filogenéticas individuais de regiões dos genes RNAr 16S, rpoC1, rbcL, tufA, e cpcBA-IGS das três linhagens de Hapalosiphon e de duas linhagens de Fischerella, CENA19 e CENA161, mostrou resultados incongruentes devido as diferentes taxas evolutivas desses genes. No entanto, a análise filogenética concatenada desses genes, mostrou que a Fischerella CENA19 agrupou com as duas linhagens de Hapalosiphon CENA71 e CENA72, com alto valor de reamostragem (100%), enquanto que a Fischerella CENA 161 e a Hapalosiphon CENA63 posicionaram-se cada uma em clados separados. Os resultados indicam que a nomenclatura das linhagens de cianobactérias da família Hapalosiphonaceae necessita de revisão. Os extratos intra e extracelulares das linhagens Fischerella sp. CENA161 e CENA19 e Hapalosiphon sp. CENA71 e CENA72 mostraram efeitos inibitórios no crescimento de bactérias patogênicas. As análises em espectrômetro de massas Q-TOF MS/MS indicaram a putativa presença de aeruginopeptina, cianopeptolina, fischerelina, aeruginosina, oscilapeptilida, microcistinas e ácido tumonóico nos extratos. No extrato intracelular da Fischerella sp. CENA161 identificou-se três ou quatro variantes de microcistinas, LR, LL, FR e/ou M(O)R. Fragmentos dos genes mcyA, mcyB, mcyC, mcyD, mcyE, mcyG e mcyI dessa linhagem foram seqüenciados. Nas duas análises filogenéticas realizadas com sequências de aminoácidos de McyE e sequências concatenadas de McyD, McyE e McyG, as enzimas da microcistina sintetase ficaram agrupadas de acordo com os gêneros de cianobactérias indicando um padrão de evolução / The generic affiliation of Fischerella and Hapalosiphon is problematic due to instability of morphological characters. The Fischerella and Hapalosiphon genera are differentiated by the presence of trichome multisseriate and uni or bisseriate, respectively. However, genetically these characters were not diacritical to distinguish genera. Molecular studies of strains isolated from Brazilian ecosystems are scarce for Fischerella and absent for Hapalosiphon. In this study, eight cyanobacterial strains, belonging to Hapalosiphonaceae family, isolated from Brazilian freshwater and soil were morphologically and genetically characterized and analyzed for bioactive compound productions. The morphological analyses identified five Fischerella (CENA19, CENA161, CENA212, CENA213, CENA214) and three Hapalosiphon (CENA63, CENA71, CENA72) morphotypes. The neighbor-Joining (NJ) and maximum likelihood (ML) phylogenetic analyses of 16S rRNA placed all isolated strains in high supported (99% NJ and ML of bootstrap) cluster containing members of the order Nostocales. Furthermore, the Fischerella strains studied were grouped in an internal clade with high bootstrap value (100% NJ and 86% ML), with exception of Fischerella CENA19. The position of this strain in the phylogenetic tree indicates that it needs taxonomical revision. The soil Hapalosiphon strains CENA71 and CENA72 also formed a separated tight internal clade (99% NJ and 98% ML), but the freshwater strain CENA63 was placed in a different clade (99% NJ and ML of bootstrap value) together with Hapalosiphon strains genera and Westielopsis prolifica SAG 16.93, originated from soil. The comparison of the phylogenetic analyses of individual regions of the genes 16S rRNA, rpoC1, rbcL, tufA, and cpcBA-IGS from the three Hapalosiphon strains and the two Fischerella strains CENA19 and CENA161 showed incongruent results due to different evolutionary rates of these genes. However, the concatenated phylogenetic analysis of these genes, showed that Fischerella CENA19 grouped with the two Hapalosiphon strains CENA71 and CENA72 with high bootstrap value (100%), while Fischerella CENA 161 and Hapalosiphon CENA63 were positionated each one in separate clades. The results indicate that the nomenclature of cyanobacterial strains from the family Hapalosiphonaceae needs revision. The intra and extracellular extracts of the Fischerella sp. strains CENA161 and CENA19 and Hapalosiphon sp. strains CENA71 and CENA72 showed inhibitory effects on the growth of pathogenic bacteria. The analysis in the mass spectrometer Q-TOF MS/MS indicated the presence of aeruginopeptin, cyanopeptolin, fischerellin, aeruginosin, oscillapeptilide, microcystins and tumonoic acid in the extracts. In the intracellular extracts of Fischerella sp. CENA161, three or four variants of microcystins, LR, LL, FR and/or M(O)R, were identified. Fragments of genes mcyA, mcyB, mcyC, mcyD, mcyE, mcyG and mcyI of this strain were sequenced. In both phylogenetic analyses performed with amino acid sequences of McyE and concatenated sequences of McyD, McyE and McyG, the microcystin synthetase enzymes were grouped according to the cyanobacterial genera, indicating a pattern of evolution

A afiliação genérica de Fischerella e Hapalosiphon é problemática devido à instabilidade dos caracteres morfológicos. Os gêneros Fischerella e Hapalosiphon são diferenciados pela presença de tricoma multisseriado e uni ou bisseriado, respectivamente. Porém, geneticamente esses caracteres não se mostraram diacríticos para diferenciar gêneros. Estudos moleculares de linhagens isoladas de ecossistemas brasileiros são escassos para Fischerella e inexistentes para Hapalosiphon. Neste estudo, oito linhagens de cianobactérias, pertencentes à família Hapalosiphonaceae, isoladas de água doce e solos brasileiros foram caracterizadas morfologicamente e geneticamente e analisadas para a produção de substâncias bioativas. As análises morfológicas identificaram cinco morfotípos de Fischerella (CENA19, CENA161, CENA212, CENA213, CENA214) e três de Hapalosiphon (CENA63, CENA71, CENA72). As análises filogenéticas do RNAr 16S usando neighbor-joining (NJ) e máxima verossimilhança (MV) colocaram todas as linhagens isoladas em um agrupamento com alto suporte (reamostragens de 99% NJ e MV) contendo membros da ordem Nostocales. Além disso, as linhagens de Fischerella selecionadas para o estudo agruparam-se em um clado interno com alto valor de reamostragem (100% NJ e 86% MV), com exceção da Fischerella CENA19. A posição dessa estirpe na árvore filogenética indica que necessita de revisão taxonômica. As linhagens de solo Hapalosiphon CENA71 e CENA72 também formaram um clado interno separado (99% NJ e 98% MV), mas a linhagem de água doce CENA63 foi colocada em um clado diferente (com valores de reamostragens de 99% NJ e MV), juntamente com linhagens do gênero Hapalosiphon e Westielopsis prolífica SAG 16.93, oriundas de solo. A comparação das análises filogenéticas individuais de regiões dos genes RNAr 16S, rpoC1, rbcL, tufA, e cpcBA-IGS das três linhagens de Hapalosiphon e de duas linhagens de Fischerella, CENA19 e CENA161, mostrou resultados incongruentes devido as diferentes taxas evolutivas desses genes. No entanto, a análise filogenética concatenada desses genes, mostrou que a Fischerella CENA19 agrupou com as duas linhagens de Hapalosiphon CENA71 e CENA72, com alto valor de reamostragem (100%), enquanto que a Fischerella CENA 161 e a Hapalosiphon CENA63 posicionaram-se cada uma em clados separados. Os resultados indicam que a nomenclatura das linhagens de cianobactérias da família Hapalosiphonaceae necessita de revisão. Os extratos intra e extracelulares das linhagens Fischerella sp. CENA161 e CENA19 e Hapalosiphon sp. CENA71 e CENA72 mostraram efeitos inibitórios no crescimento de bactérias patogênicas. As análises em espectrômetro de massas Q-TOF MS/MS indicaram a putativa presença de aeruginopeptina, cianopeptolina, fischerelina, aeruginosina, oscilapeptilida, microcistinas e ácido tumonóico nos extratos. No extrato intracelular da Fischerella sp. CENA161 identificou-se três ou quatro variantes de microcistinas, LR, LL, FR e/ou M(O)R. Fragmentos dos genes mcyA, mcyB, mcyC, mcyD, mcyE, mcyG e mcyI dessa linhagem foram seqüenciados. Nas duas análises filogenéticas realizadas com sequências de aminoácidos de McyE e sequências concatenadas de McyD, McyE e McyG, as enzimas da microcistina sintetase ficaram agrupadas de acordo com os gêneros de cianobactérias indicando um padrão de evolução / The generic affiliation of Fischerella and Hapalosiphon is problematic due to instability of morphological characters. The Fischerella and Hapalosiphon genera are differentiated by the presence of trichome multisseriate and uni or bisseriate, respectively. However, genetically these characters were not diacritical to distinguish genera. Molecular studies of strains isolated from Brazilian ecosystems are scarce for Fischerella and absent for Hapalosiphon. In this study, eight cyanobacterial strains, belonging to Hapalosiphonaceae family, isolated from Brazilian freshwater and soil were morphologically and genetically characterized and analyzed for bioactive compound productions. The morphological analyses identified five Fischerella (CENA19, CENA161, CENA212, CENA213, CENA214) and three Hapalosiphon (CENA63, CENA71, CENA72) morphotypes. The neighbor-Joining (NJ) and maximum likelihood (ML) phylogenetic analyses of 16S rRNA placed all isolated strains in high supported (99% NJ and ML of bootstrap) cluster containing members of the order Nostocales. Furthermore, the Fischerella strains studied were grouped in an internal clade with high bootstrap value (100% NJ and 86% ML), with exception of Fischerella CENA19. The position of this strain in the phylogenetic tree indicates that it needs taxonomical revision. The soil Hapalosiphon strains CENA71 and CENA72 also formed a separated tight internal clade (99% NJ and 98% ML), but the freshwater strain CENA63 was placed in a different clade (99% NJ and ML of bootstrap value) together with Hapalosiphon strains genera and Westielopsis prolifica SAG 16.93, originated from soil. The comparison of the phylogenetic analyses of individual regions of the genes 16S rRNA, rpoC1, rbcL, tufA, and cpcBA-IGS from the three Hapalosiphon strains and the two Fischerella strains CENA19 and CENA161 showed incongruent results due to different evolutionary rates of these genes. However, the concatenated phylogenetic analysis of these genes, showed that Fischerella CENA19 grouped with the two Hapalosiphon strains CENA71 and CENA72 with high bootstrap value (100%), while Fischerella CENA 161 and Hapalosiphon CENA63 were positionated each one in separate clades. The results indicate that the nomenclature of cyanobacterial strains from the family Hapalosiphonaceae needs revision. The intra and extracellular extracts of the Fischerella sp. strains CENA161 and CENA19 and Hapalosiphon sp. strains CENA71 and CENA72 showed inhibitory effects on the growth of pathogenic bacteria. The analysis in the mass spectrometer Q-TOF MS/MS indicated the presence of aeruginopeptin, cyanopeptolin, fischerellin, aeruginosin, oscillapeptilide, microcystins and tumonoic acid in the extracts. In the intracellular extracts of Fischerella sp. CENA161, three or four variants of microcystins, LR, LL, FR and/or M(O)R, were identified. Fragments of genes mcyA, mcyB, mcyC, mcyD, mcyE, mcyG and mcyI of this strain were sequenced. In both phylogenetic analyses performed with amino acid sequences of McyE and concatenated sequences of McyD, McyE and McyG, the microcystin synthetase enzymes were grouped according to the cyanobacterial genera, indicating a pattern of evolution

Most free-living bacteria will encounter different environments and it is therefore critical to be able to rapidly adjust to new growth conditions in order to be competitively successful. Responding to changes requires efficient gene regulation in terms of transcription, RNA stability, translation and post-translational modifications. Studies of an extremely slow-growing mutant of Salmonella enterica, with a Glu125Arg mutant version of EF-Tu, revealed it to be trapped in a stringent response. The perceived starvation was demonstrated to be the result of increased mRNA cleavage of aminoacyl-tRNA synthetase genes leading to lower prolyl-tRNA levels. The mutant EF-Tu caused an uncoupling of transcription and translation, leading to increased turnover of mRNA, which trapped the mutant in a futile stringent response. To examine the essentiality of RNase E, we selected and mapped three classes of extragenic suppressors of a ts RNase E phenotype. The ts RNase E mutants were defective in the degradation of mRNA and in the processing of tRNA and rRNA. Only the degradation of mRNA was suppressed by the compensatory mutations. We therefore suggest that degradation of at least a subset of cellular mRNAs is an essential function of RNase E. Bioinformatically, we discovered that the mRNA of tufB, one of the two genes encoding EF-Tu, could form a stable structure masking the ribosomal binding site. This, together with previous studies that suggested that the level of EF-Tu protein could affect the expression of tufB, led us to propose three models for how this could occur. The stability of the tufB RNA structure could be affected by the elongation rate of tufB-translating ribosomes, possibly influenced by the presence of rare codons early in the in tufB mRNA. Using proteomic and genetic assays we concluded that two previously isolated RNAP mutants, each with a growth advantage when present as subpopulations on aging wild-type colonies, were dependent on the utilization of acetate for this phenotype. Increased growth of a subpopulation of wild-type cells on a colony unable to re-assimilate acetate demonstrated that in aging colonies, acetate is available in levels sufficient to sustain the growth of at least a small subpopulation of bacteria.

In addition to a loss of potential revenues from Utah's $393 million sport fishing industry, the state expends millions of dollars every year on costs associated with whirling disease mitigation and prevention. A state fish hatchery at Midway, Utah was closed when the shallow unconfined aquifer being used for fish culture by spring discharge was deemed to be contaminated by whirling disease. An alternative water source may exist in a confined aquifer below this contaminated unconfined aquifer. However, the complex hydrostratigraphy presents a challenge in determining if this source is a viable resource for fish culture. Geological, physical, chemical, geophysical, and isotopic data were combined to create a conceptual model of the groundwater flow at the site and to determine the interactions this confined aquifer may have with the contaminated aquifer. This model divides groundwater at the hatchery into a shallow unconfined system, an upper confined system, and a lower confined system. The shallow unconfined system is characterized by a water table ~1m below ground surface, several active springs, fast travel times, modern water mixed with ancient hydrothermal water, relatively high TDS, and relatively enriched isotopic values. The confined aquifers have a smaller hydrothermal component, relatively depleted isotopic values, lower TDS, and modern recharge components. Two orthogonal shallow high-resolution seismic reflection profiles indicate substantial heterogeneity in the subsurface at the level of the confined systems at the hatchery. Several north-south trending normal discontinuities were interpreted as possible faults from the seismic profile oriented as a dip line, whereas the strike profile shows discontinuous layering without noticeable faulting. A well log profile for the site shows discontinuous tufa layers amid heterogeneous alluvium material. These tufa layers separate upward leaking confined aquifers from the unconfined system. It is only through the integration of several methods that such mixed systems, can be understood. In this study, the lower confined aquifer was found to be a sufficient and safe resource through the integration of numerous methods.

Le travertin, connu sous le terme de lapis tiburtinus dans l’Antiquité romaine, est une roche issue de la précipitation du carbonate dissous dans les eaux de sources chaudes (travertins) ou froides (tufs calcaires), sous l’influence de processus physico-chimiques et/ou biologiques. Ce phénomène est décrit dès l’époque gréco-romaine par les auteurs antiques (Strabon, Pline l’Ancien, Vitruve), qui témoignent d’une roche qui se forme sous leurs yeux, qui dessine le paysage et qui est largement exploitée pour la construction (p. ex. le Colisée à Rome, le Temple grec de Ségeste en Sicile). Abondamment répartis à la surface de la Terre et caractérisés par une certaine diversité morphologique, les travertins représentent d’excellents enregistreurs des conditions climatiques et hydrologiques de leur dépôt, offrant un potentiel très fiable d’archives sédimentaires utilisées au sein de problématiques paléoenvironnementales. La notion de travertins anthropiques définie ici prend en compte l’influence de l’Homme sur ces formations sédimentaires et les eaux qui leur sont associées. Elle est illustrée par une approche géoarchéologique des dépôts de travertins préservés sur le site antique de Jebel Oust, en Tunisie, où l’exploitation d’une source chaude est attestée depuis le début de notre ère jusqu’à son tarissement dès la fin de l’Antiquité tardive. La source thermale surgissant sur le versant oriental de la montagne fut l’objet d’un culte aux époques romaine puis paléochrétienne et alimentait en eau chaude, par le biais d’un aqueduc, un édifice thermal localisé en aval. Notre approche géoarchéologique met en lumière l’anthropisation du versant qui se traduit par un contrôle du fonctionnement de la source chaude et des dynamiques sédimentaires associées. En parallèle, l’analyse des travertins préservés au sein des structures antiques révèle des informations primordiales sur les conditions de déroulement du culte et sur les pratiques balnéaires (fonction des salles thermales, gestion de l’eau, phases de réfection, états d’abandon). Une vision plus générale d’une géoarchéologie des travertins anthropiques propose une nouvelle approche des problématiques liées à l’eau, en insistant sur la gestion plus ou moins complexe d’une source carbonatée, chaude ou froide, et en précisant le degré d’impact humain sur le développement des travertins. / Travertine, known as lapis tiburtinus during Roman times, are continental limestones precipitated in calcareous environments from thermal waters of hot springs (travertine) or cool waters of karstic springs (calcareous tufa). This phenomenon is well-known during Classical Antiquity and had been described by several ancient authors (Strabo, Pliny the Elder, Vitruvius) who depicted a stone that forms extremely rapidly, a stone that outlines the landscape and which is largely used for construction (e.g. The Colosseum in Roma, the Greek temple at Segesta in Sicily). These deposits are widespread on Earth’s surface showing various morphologies and are great sedimentary records of climatic and hydrologic conditions. Thus they represent valuable proxies for palaeoenvironmental studies. The notion of anthropogenic travertine takes into consideration human impact on these deposits and on travertine-depositing waters. It is documented by the study of the roman site of Jebel Oust, Tunisia, where the exploitation of a hot spring is attested from the first century A.D. to the end of Late Antiquity. The site is characterized by a temple settled around the spring’s vent associated with Roman baths located downstream and supplied with hot water via an aqueduct. Our geoarchaeological approach brings to light the anthropization of the regional geosystem expressed by an entire control over the hot spring and its associated deposits. Furthermore the study of travertines preserved in the archaeological structures reveals precious and original information about water cult and bathing practices during Antiquity (thermal rooms function, water management, repair phases, states of neglect and decay). Moreover, geoarchaeology of anthropogenic travertine intends to offer a new approach of research‘s problematic dealing with water managements and integrating human impact on travertine’s development.

No description available.