A new cyanobacterial species with a protective effect on lettuce grown under salinity stress: envisaging sustainable agriculture practices

In this work, a new terrestrial cyanobacterial species, Oculatella lusitanica LEGE 161147, was isolated and characterized using a polyphasic approach. Morphologically, O. lusitanica shares characteristics with different Oculatella species (mainly with O. crustae-formantes), lacking distinctive features. However, the phylogeny based on the 16S rRNA gene sequence and the 16S-23S ITS secondary structures support the establishment of this isolate as a new species. O. lusitanica is placed within a clade mainly composed by other Oculatella terrestrial strains; however, it forms a separate lineage. In addition, our species differs from the other Oculatella described so far by lacking the V2 helix within the ITS region. Since cyanobacteria are known to release compounds that promote plant growth and/or increase their tolerance to stresses, the effect of this newly described cyanobacterial species on Lactuca sativa (lettuce) plants development and salinity stress resistance was evaluated. Our results showed that, although the cyanobacterium had no impact on plant growth under the conditions tested, it was able to mitigate the deleterious salinity stress effects on plant size, root and aerial part fresh weight, by eliciting the non-enzymatic antioxidant response system (proline, H2O2 and reduced glutathione). In addition, the microorganism was able to induce a priming effect on lettuce plants by stimulating defensive mechanisms under non-stress conditions, and enhances the activity of nitrogen metabolism-related enzymes glutamate dehydrogenase, glutamine synthetase and nitrate reductase. These results indicate that this native terrestrial cyanobacterial species could be employed as a tool in sustainable agricultural practices.This work was funded by National Funds through FCT—Fundação para a Ciência e a Tecnologia, I.P., under the projects PCIF/RPG/0077/2017, UIDB/04293/2020, UIDP/04293/2020, UIDB/05748/2020 and UIDP/05748/2020. This work was also funded by the FCT grant SFRH/BPD/115571/2016 (to AB) and LTAUSA 18008 (to JK)info:eu-repo/semantics/publishedVersio

Measurement system with preamplifier for calibration of vibration sensors

This thesis deals with the design and implementation of a preamplifier for vibration sensors with IEPE interface and also for vibration sensors with charge output. The thesis also deals with a modification of a computer application for a measuring system in LabVIEW. The thesis builds on the already implemented measuring system for secondary calibration of vibration sensors. The results of the secondary calibration of this system with the added preamplifier are compared with the results of a primary calibration

Measurement system with preamplifier for calibration of vibration sensors

Práce se zabývá návrhem a také samotnou realizací předzesilovače pro snímače vibrací s rozhraním IEPE a také pro snímače vibrací s nábojovým výstupem. Součástí práce je úprava počítačové aplikace pro měřicí systém v prostředí LabVIEW. Práce navazuje na již realizovaný měřicí systém pro sekundární kalibraci snímačů vibrací. Jsou porovnány výsledky sekundární kalibrace systému s doplněným předzesilovačem s výsledky primární kalibrace.This thesis deals with the design and implementation of a preamplifier for vibration sensors with IEPE interface and also for vibration sensors with charge output. The thesis also deals with a modification of a computer application for a measuring system in LabVIEW. The thesis builds on the already implemented measuring system for secondary calibration of vibration sensors. The results of the secondary calibration of this system with the added preamplifier are compared with the results of a primary calibration.

True branched nostocalean cyanobacteria from tropical aerophytic habitats and molecular assessment of two species from field samples

Aerophytic cyanobacteria are commonly found growing on rocks, tree trunks and soil, but the diversity of these organisms is still poorly known. This complex group is very problematic considering the taxonomic arrangement and species circumscription, especially when taking into account tropical populations. In this work, 20 samples of aerophytic cyanobacteria from 15 distinct sampling sites were collected along a tropical rainforest area at the São Paulo State (Brazil). Samples were dried at room temperature after the collection, and once in the laboratory, they were rehydrated and analyzed. The taxonomic study resulted in the record and description of nine species of true-branched cyanobacteria pertaining to the genera Spelaeopogon (one specie), Hapalosiphon (two species) and Stigonema (six species). The similarity of the flora found when compared to surveys conducted in other geographical regions was relatively low. These differences could be addressed to ecological conditions of the habitats, to the extension of the area surveyed or even to taxonomic misinterpretations. The molecular assessment of 16S rDNA on the basis of field material was successful for two morphospecies, Hapalosiphon sp. and Stigonema ocellatum; however, their relationships with other populations and species revealed to be uncertain. The results of the floristic survey and of the molecular approach evidenced the fragile delimitation of some genera and species in the true branched group of cyanobacteria.Las bacterias aerofíticas crecen comúnmente en las rocas, troncos de árboles y el suelo, pero la diversidad de estos organismos todavía es poco conocida. Este complejo grupo es muy problématico considerando la disposición taxónomica y la circunscripción de las especies, especialmente cuando se toman en cuenta las poblaciones tropicales. En esta investigación, 20 muestras de cianobacterias aerofíticas de 15 distintos sitios de muestro fueron recolectadas a lo largo de un área de selva tropical en el estado de São Paulo (Brasil). Las muestras fueron secadas a temperatura ambiente después de su recolecta, y una vez en el laboratorio, se hidrataron y analizaron. El estudio taxónomico resultó en un registro y descripción de nueve especies de cianobacterias con ramificaciones verdaderas pertenecientes al género Spelaeopogon (una especie), Hapalosiphon (dos especies) y Stigonema (seis especies). La similutud de la flora encontrada en comparación con las encuestas realizadas en otras regiones geográficas fue relativamente baja. Estas diferencias podrían deberse a las condiciones ecológicas de los hábitats, a la extensión de la zona de estudio o incluso a malas interpretaciones taxonómicas. La evaluación molecular del 16S rDNA del material de campo fue un éxito para dos morfoespecies, Hapalosiphon sp. y Stigonema ocellatum, sin embargo, sus relaciones con otras poblaciones y especies revelan que son inciertas. Los resultados del estudio florístico y de la aproximación molecular evidencian la débil delimitación de algunos géneros y especies en el grupo de cianobacterias con ramificaciones verdaderas

True branched nostocalean cyanobacteria from tropical aerophytic habitats and molecular assessment of two species from field samples

Aerophytic cyanobacteria are commonly found growing on rocks, tree trunks and soil, but the diversity of these organisms is still poorly known. This complex group is very problematic considering the taxonomic arrangement and species circumscription, especially when taking into account tropical populations. In this work, 20 samples of aerophytic cyanobacteria from 15 distinct sampling sites were collected along a tropical rainforest area at the São Paulo State (Brazil). Samples were dried at room temperature after the collection, and once in the laboratory, they were rehydrated and analyzed. The taxonomic study resulted in the record and description of nine species of true-branched cyanobacteria pertaining to the genera Spelaeopogon (one specie), Hapalosiphon (two species) and Stigonema (six species). The similarity of the flora found when compared to surveys conducted in other geographical regions was relatively low. These differences could be addressed to ecological conditions of the habitats, to the extension of the area surveyed or even to taxonomic misinterpretations. The molecular assessment of 16S rDNA on the basis of field material was successful for two morphospecies, Hapalosiphon sp. and Stigonema ocellatum; however, their relationships with other populations and species revealed to be uncertain. The results of the floristic survey and of the molecular approach evidenced the fragile delimitation of some genera and species in the true branched group of cyanobacteria.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Determinants of cyanobacterial species composition in the splash zone of two Croatian islands

<p>Cyanobacterial communities of the splash zone of two Croatian islands, Veruda and Ugljan, were surveyed. At each island, we studied eight localities with different aspects. From all 336 samples, a total of 42 cyanobacterial species, one green alga, and one red alga were found. In both islands <i>Hyella</i> spp. and <i>Gloeocapsopsis crepidinum</i> dominated and <i>Entophysalis deusta, Solentia</i> spp., <i>Kyrtuthrix dalmatica</i> and <i>Mastigocoleus testarum</i> were found frequently. Multivariate statistical analysis of species composition shows that the vertical gradient is the strongest determinant of species composition and that there are statistically significant but not very pronounced differences in species composition between the two islands. Species composition among individual sites within islands differed slightly, and between localities decreased rather slowly with the distance of individual samples (i.e. the similarity distance decay was very slow), showing that even close samples can have quite different species composition. The species accumulation curves do not reach their asymptote, indicating that many samples are needed to reasonably cover the species richness of a site. This study highlights the importance of in-depth species counts and high density sampling along vertical gradients for satisfactory cyanobacterial community assessments in marine coastal splash zones.</p

Hot Is Rich—An Enormous Diversity of Simple Trichal Cyanobacteria from Yellowstone Hot Springs

In 2019, cyanobacterial samples were collected from thermal sites in Yellowstone National Park. In this paper, we discuss the considerable richness of representatives of simple filamentous cyanobacteria. Using a polyphasic approach, one new genus, Copelandiella, with two species (C. yellowstonensis and C. thermalis) and eight additional new species Albertania prattii, K. anagnostidisii, Kovacikia brockii, Leptolyngbya tildenae, L. vaporiphila, Nodosilinea calida, N. igneolacustris, and Oculatella castenholzii were described. At the same time, by analyzing our new molecular data, we concluded that other genera of trichal cyanobacteria can be merged with existing genera: species within the genus Plectolyngbya are herein transferred to Leptolyngbya, and if some nomenclatural issues are resolved, species within the genus Leptothermofonsia will be subsequently transferred to the genus Kovacikia, an earlier synonym

The polyphasic analysis of two native Raphidiopsis isolates supports the unification of the genera Raphidiopsis and Cylindrospermopsis (Nostocales, Cyanobacteria)

Raphidiopsis and Cylindrospermopsis are planktic, freshwater bloom-forming cyanobacteria of great concern to human health due to the production of potent cyanotoxins. The presence (in Cylindrospermopsis) or absence (in Raphidiopsis) of heterocytes is the traditional character used to distinguish them. This has led to misidentifications and to questions about the validity of the genus Raphidiopsis. We studied two strains of R. mediterranea isolated from Argentinean shallow lakes using a polyphasic approach that included the morphological description of the natural populations and their ultrastructural, physiological and molecular characterisation. Heterocyte differentiation was not observed in the field or in cultures of R. mediterranea submitted to nitrogen deprivation. These results support the occurrence of stable native populations of R. mediterranea without heterocytes, which would not be a part of the Cylindrospermopsis complex life cycle. Based on 16S rRNA, 16S–23S ITS, and cpcBA-IGS sequences, these two genera are virtually identical. Thus, strains of Raphidiopsis and Cylindrospermopsis make up a monophyletic lineage in all phylogenetic reconstructions. Furthermore, the 16S–23S ITS secondary structure provided further evidence that these two genera cannot be separated. The intermixed position in the trees points to several losses of heterocytes during the evolution of these cyanobacteria. We conclude that these two genera should not be regarded as separate and distinct generic units and propose their unification under the name Raphidiopsis, respecting the principle of priority. Accordingly, we revisited and emended the description of Raphidiopsis.Fil: Aguilera, Anabella. Fundación para Investigaciones Biológicas Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; ArgentinaFil: Berrendero Gómez, Esther. University of South Bohemia; República ChecaFil: Kaštovský, Jan. University of South Bohemia; República ChecaFil: Echenique, Ricardo Omar. Facultad de Ciencias Naturales y Museo, Universidad Nacional de la Plata; ArgentinaFil: Salerno, Graciela Lidia. Fundación para Investigaciones Biológicas Aplicadas; Argentin

Using single cell/filament PCR method for study non-cultured cyanobacteria

Cyanobacteria are photosynthetic prokaryotic organisms, and they are believed to be the Earth’s oldest life form. They were responsible for forming the oxygen on the Earth and from then they have been able to adapt to a multitude of environmental conditions, which allowing to be present in a wide range of habitats. When it comes to perform ecological and/or taxonomic studies one of problems which we must confront is the fact of some cyanobacteria are present in the nature in a few amounts, going unnoticed. Moreover, some of them show large mucilaginous sheaths, which making difficulted its isolation and growth later in culture. All these aspects have hindered the molecular assessment of a large portion of traditional cyanobacterial taxa, as Rivularia and Stigonema, especially necessary evaluation in the taxonomic studies. Rivularia genus grows on submerged stones, rocks, and damp soils near riverbanks, often on calcareous substrates and in clear, unpolluted, and streaming or stagnant waters, but also there are several species known from marine littoral. However, Stigonema genus grows aerophytically or subaerophytically on bark of trees or wet rocks, from lowland to the alpine zone of high mountains, but also several species are known from pools, swamps and moors. In this study, several Rivularia colonies collected in the Croatian Adriatic coast and several Stigonema species from Spanish alpine terrestrial environments are being analysed. The used methodology consists of a number of stages. In the first step, the samples are washed in EDTA disodium salt solution for dissolving the associated of calcium carbonate deposits (STEP 1). For the isolation of single cells and filaments, we are using a modified single filament isolation technique for planktonic cyanobacteria applying a glass capillary under sterile conditions (Zapomělová et al. 2008) described by Mareš et al. 2015 (STEP 2). Then, an optimized protocol we are utilized for amplification of the 16S rRNA gene, the associated 16S–23S internal transcribed spacer (ITS) region and the partially the 23S rRNA gene (2,000-2,500 bp) (Berrendero et al. 2016) (STEP 3). Finally, sequences analysis will carry out to determine the phylogenetic position of the different genotypes found inside a same Rivularia colony to be able to relation them with the morphotypes observed by the microscope. In the case of the Stigonema samples, we have successfully gotten the isolation of several filaments and, at the present, we are working on the amplification the studied region. This methodology, based on a glass capillary isolation technique and a PCR protocol for amplification of specific sequences, has been applied with success in the Rivularia and Stigonema samples without the need to cultivate them. Our future research will focus on the amplification of several taxonomic marker genes at the same time