Comprehensive Investigation of a Toxic Microcystis sp. (Cyanobacteria) Collected from Snow Lake (New Mexico, USA).

The toxin producing cyanobacterium Microcystis sp. was collected in the mid October 2020 from the shallow waters of Snow Lake (New Mexico, USA). This species caused a visible bloom consisting of the pale green irregular macro colonies. Mass spectral analysis of the biomass revealed the presence of 4 derivatives of microcystin in that bloom: MC-LR (in the water and biomass), MC-RR (in biomass), MC-LY (in biomass), and MC-YR (in biomass).Next-generation sequencing allowed the retrieval of two Microcystis sequences in the bloom; which are molecular benchmarks for toxic Microcystis that may be used in future monitoring studies. Light microscopy provided evidence for the taxonomic affiliation of the found morphotype as Microcystis flos-aquae (Wittrock) Kirchner. However, molecular sequencing and the present situation in cyanobacterial taxonomy prevented affiliation of our morphotype to Microcystis flos-aquae, justifying following name – Microcystis sp. Confocal microscopy was used to determine the distribution of the cell content utilizing 3D stereo imaging. Emission spectra analysis identified the pigment composition and pigment distribution within the cells. SEM revealed 3D arrangement of the cells in the colonies, texture of the surface of the cells (perhaps dehydrated collapsed polysaccharides), F-layer and pili-like structures. Additionally, SEM/EDS analysis confirmed the F-layer using elemental composition analysis, which showed sulfur in the F-layer – typical element for that structure. Through the use of AFM, we analyzed the texture of the cell's surface and confirmed pili-like structures.

The Arabidopsis Accessions Selection Is Crucial: Insight from Photosynthetic Studies

Natural genetic variation in photosynthesis is strictly associated with the remarkable adaptive plasticity observed amongst Arabidopsis thaliana accessions derived from environmentally distinct regions. Exploration of the characteristic features of the photosynthetic machinery could reveal the regulatory mechanisms underlying those traits. In this study, we performed a detailed characterisation and comparison of photosynthesis performance and spectral properties of the photosynthetic apparatus in the following selected Arabidopsis thaliana accessions commonly used in laboratories as background lines: Col-0, Col-1, Col-2, Col-8, Ler-0, and Ws-2. The main focus was to distinguish the characteristic disparities for every accession in photosynthetic efficiency that could be accountable for their remarkable plasticity to adapt. The biophysical and biochemical analysis of the thylakoid membranes in control conditions revealed differences in lipid-to-protein contribution, Chlorophyll-to-Carotenoid ratio (Chl/Car), and xanthophyll cycle pigment distribution among accessions. We presented that such changes led to disparities in the arrangement of the Chlorophyll-Protein complexes, the PSI/PSII ratio, and the lateral mobility of the thylakoid membrane, with the most significant aberrations detected in the Ler-0 and Ws-2 accessions. We concluded that selecting an accession suitable for specific research on the photosynthetic process is essential for optimising the experiment.

Pattern Dystrophies

Pattern dystrophies have been known since 1950 which have autosomal dominant inheritance pattern. Pattern dystrophies have been classified based on the pattern of the pigment distribution. Despite significant retinal changes, good visual acuity is often maintained. However, complications such as choroidal neovascular membrane and retinal atrophy may develop in older patients and can significantly decrease visual acuity. There is no specific treatment, but when complications arise, treatment should be done by reason.

X-ray microscopy reveals the outstanding craftsmanship of Siberian Iron Age textile dyers

The excellent craftsmanship of ancient Oriental and Central Asian textile dyers is already demonstrated in the remarkable brilliance and fastness of the colours of the so-called Pazyryk carpet, the by far oldest pile carpet found to date. This specimen resembles the advanced craftsmanship of Iron Age Central Asian textile production. We have employed synchrotron-based µ-XRF imaging to detect the distribution of metal organic pigments within individual fibres of the Pazyryk carpet (about 2500 years old) and compare the results to wool fibres, which we prepared according to traditional Anatolian dyeing recipes. We observe congruent pigment distribution within specimens from the Pazyryk carpet and natural wool fibres that we have fermented prior to dyeing. Therefore, we conclude that the superior fermentation technique has been utilized about 2000 years earlier than known so far.

Flower color digitizing and pigment distribution in garden pansy

The garden pansy (Viola × wittrockiana) is a large hybrid flower and most popular for its abundant flower colors. The flower colors of 12 pansy accessions were measured by using colorimeter and the pigments distribution within their petal cells were investigated. The result indicated a vast majority of the visual color of flower was consistent with the result surveyed by colorimeter in pansy. The pigments were mainly distributed in the upper and dorsal epidermal cells and most of them show the similar colors to those measured using colorimeter. The red pigment was found to be distributed in the visual blue petals and yellowish brown or khaki pigment in visual white petals. The results suggested the flower color of pansy can be objectively and accurately measured with colorimeter, and investigating pigment color and distribution in petals can help understanding pansy flower color better.

Detecting microbial pigments from gypsum using Raman spectroscopy: from field prospection to laboratory studies

<p>Terrestrial detection of biomarkers in various mineral matrices using Raman spectrometers including field deploying of miniature instrumentation in Mars-analogue sites can be seen as a training for next Martian missions. In fact, both the European Space Agency (Exomars) and North American Space Agency (Mars 2020) robotic rovers will include Raman spectrometers. Feasibility of detecting biomarkers of extremophilic cyanobacteria and algae (pigments, osmotic solutes and lipids) using Raman microspectrometry was reviewed previously. Here the idea is to show - firstly how portable Raman instrumentation permits to detect carotenoids fast and onsite under field conditions. Secondly, laboratory microspectrometric investigations allow to obtain more detailed information about spatial distribution of pigments originating from microorganisms.</p><p>Macrocrystalline gypsum layers and aggregates are well-known from Tertiary series in Sicily and Eastern Poland. In Southern Sicily gypsum sediments accumulated during Messinian crisis (Late Miocene) are outcroping and were investigated near Scala dei Turchi, Torre Salsa and Siculiana Marina. Polish Tertiary (Badenian, Middle Miocene) examples of gypsum colonisations of decimetre long outcropping crystals were studied near Chotel Czerwony, Skorocice and Chwalowice. Miniature portable Raman spectrometers equipped with green lasers allowing recording of resonance Raman signals of carotenoids are evaluated here. Possibilities of collecting spectra of carotenoids under non-resonant conditions using a portable sequentially shifted Raman spectrometer (785 and 853nm lasers) are shown as well. Observed shifts of positions of Raman features of carotenoids between gypsum samples (and sites) are discussed and critically evaluated. In addition, acquired data are compared to data obtained through laboratory Raman microspectrometric investigations. Selected zones of microbial colonisations of few types of gypsum are described from the point of view of the presence of algae and cyanobacteria. Pigments are detected through conventional Raman microspectrometric measurements. Carotenoids were documented in major part of samples (common Raman bands at around 1525, 1157, and 1004 cm<sup>−1</sup>). Additionally, Raman spectra of other pigments were recorded in several zones using near infrared excitation (785 nm): chlorophyll (1151, 1327, 1287, 1184, 917, and 745 cm<sup>−1</sup>), scytonemin (1593, 1152, 1438, and 1173 cm<sup>−1</sup>) and phycobiliproteins (1633, 1584, 1371, 1236, 813, and 667 cm<sup>−1</sup>).</p><p>Portable instrumentation permits detection of carotenoids in gypsum fast and onsite under field conditions. Raman microspectrometric investigations of colonisations allow to gather detailed information about pigment distribution in micrometric zones of gypsum samples.</p>