Pigment Composition Research Articles

Isolation, Identification and Pigment Analysis of Novel Cyanobacterial Strains from Thermal Springs

Cyanobacterial pigments have attracted considerable attention in industry due to their bioactive potential and natural origin. In the present study, the growth dynamics and pigment composition, in terms of chlorophyll a, total carotenoids and phycobiliprotein content, of four cyanobacterial strains isolated from thermal springs, namely Oscillatoria subbrevis CZS 2201, Phormidium ambiguum CZS 2205, Nostoc calcicola TSZ 2203, and Synechococcus sp. CZS 2204, were investigated. The analysis revealed that the maximum quantity of chlorophyll a and total carotenoids was observed in Oscillatoria subbrevis CZS 2201 (26.49 and 3.44 µg mL−1), followed by Phormidium ambiguum CZS 2205 (18.64 and 2.32 µg mL−1), whereas a minimum amount was detected in Synechococcus sp. CZS 2204 (12.13 and 1.24 µg mL−1), respectively. In addition, Oscillatoria subbrevis CZS 2201 showed higher quantity of phycobiliproteins, especially C-phycocyanin (45.81 mg g−1), C-phycoerythrin (64.17 mg g−1) and C-allophycocyanin (27.45 mg g−1). Moreover, carotenoid derivatives of Oscillatoria subbrevis CZS 2201 were also identified, among which β-carotene was the dominant form (1.94 µg mL−1), while the accumulation of zeaxanthin and myxoxanthophyll was relatively high (0.53 and 0.41 µg mL−1, respectively) compared with echinenone and cryptoxanthin (0.34 and 0.23 µg mL−1, respectively). The study revealed that Oscillatoria subbrevis CZS 2201 was a potent producer of secondary carotenoids, including myxoxanthophyll.

A Study on Pigment Composition of Buddhist Cave Paintings Based on Hyperspectral Technology

The value of the Buddhist cave lies not only in the Buddha statues but also in the surface painting. Hyperspectral imaging technology, as an emerging and effective method for component identification, offers a non-contact and non-destructive approach to the preservation and restoration of oil paintings. This study employed hyperspectral cameras to capture common pigments on the surfaces of Buddhist caves. Then, the results were processed and used as a database to identify the paintings. Additionally, a series of experiments were conducted to examine the impact of binder, substrate types, and pigment sizes on the reflectance spectrum of the paints. The Spectral Angle Matching (SAM) algorithm was then used to analyze the Yuanjue Cave and Qiqushan Stone Carvings of the Tang Dynasty in China. The findings revealed that the position of absorption peaks in the reflectance spectra is not significantly influenced by the substrate but is affected by the binder. Moreover, the absorption depth varies regularly with particle size. Furthermore, the spectral matching results demonstrate that components can be accurately identified even for similar colors. Based on the pigment distribution, the study also inferred specific details of ancient paintings, including the painting steps and hidden information in the manuscript layout. These findings hold significant implications for the restoration of representative surface paintings of the Tang Dynasty Buddhist cave, providing a reference for the selection of restoration materials and methods.

A portable and low-cost optical device for pigment-based taxonomic classification of microalgae using machine learning

The proliferation of certain phytoplankton species may lead to harmful algal blooms (HABs) that can affect living resources and human health. Therefore, an accurate identification of phytoplankton populations is essential for the sustainable management of some activities relevant for the blue economy, such as aquaculture, being also relevant for environmental monitoring and marine research purposes. Microalgae taxonomic discrimination, based on their pigment composition, is a versatile and promising technique to detect and identify potential HABs. In this work, a portable and low-cost device for taxonomic identification of microalgae, based on the pigment composition of 16 species belonging to 6 different phyla, was developed. It uses the fluorescence intensity signal emitted by each species at three wavelengths (575 nm, 680 nm and 730 nm) when excited at five wavelengths (405 nm, 450 nm, 500 nm, 520 nm and 623 nm) to create a fluorescence signature for each species. Furthermore, several machine learning classifiers were studied using this fluorescence signature as features to train and classify each species according to their respective taxonomic group. The Extreme Gradient Boosting (XGBoost) classifier was able to correctly predict microalgae monocultures with 97 % accuracy at the phylum level and 92 % accuracy at the order level. The obtained results confirm the potential of this technique for fast, accurate and low-cost identification of microalgae.

Effects of light spectra on growth and compositions of biomass, fatty acids, and pigments in three typical microalgae from different phyla

Effects of light spectra on growth and compositions of biomass, fatty acids, and pigments in three typical microalgae from different phyla

Bio-prospecting the Anti-oxidative and Radioprotective Role of Bioactive Pigment Isolated from Pontibacter indicus

Aim: To evaluate the anti-oxidative and radioprotective role of Pontibacter indicus SCG24 pigment during radiation exposure Background: Radiation-induced cytotoxicity is quite common during cancer therapy. There is a need for naturally derived therapeutic molecules that can scavenge free radicals. They may act as substitutes for synthetic molecules. Hence, there is a need for urgent evaluation of these potent compounds before therapeutic application. Objective: The objective of this study is to examine the anti-oxidative and radioprotective role of P. indicus SCG24 pigment, specifically to evaluate free radical scavenging X-ray irradiated HDF cells Method: A radiotoleraent pigment-producing P. indicus SCG24 was isolated from pharmaceutical effluent. Chloroform was used as a primary solvent for pigment extraction. GCMS/MS analysed initial pigment composition. Various In-vitro antioxidant assays were performed using ABTS, FRAP, and DPPH assay. Flow cytometry was used to determine the rate of scavenging activity of pigment in HDF cells. Results: The GCMS/MS profile of the chloroform extract revealed twenty-two compounds. Furthermore, based on the DPPH, ABTS, and FRAP assay, the pigment was found to have significant antioxidant properties. The flow cytometry results indicate that the pigment possesses radioprotectant activity by neutralizing ROS species in HDF cells when exposed to X-ray radiation. Conclusion: These observations on P. indicus SCG24 pigment suggested that the pigment may have potential therapeutic importance.

Mining and expression analysis of color related genes in Bougainvillea glabra bracts based on transcriptome sequencing.

Bract coloration is one of the key ornamental traits in Bougainvillea, yet research has predominantly focused on phenotypic color traits and pigment composition, with limited understanding of the molecular mechanisms underlying color formation. This gap hinders the improvement and innovation in bract coloration. To elucidate the regulatory mechanisms of bract coloration in Bougainvillea and to enhance the utilization of its germplasm resources, this study employed the Illumina Novaseq 6000 sequencing platform to conduct transcriptomic sequencing on 21 samples of bracts exhibiting seven distinct phenotypes. Comparative analysis against Nr, Pfam, EggNOG, GO, and KEGG databases annotated 90,279 unigenes. The highest annotation rates were achieved with the Nr (40.13%), GO (30.44%), and EggNOG (25.64%) databases. Among the species annotated, Beta vulgaris (20.08%) and Chenopodium quinoa (14.58%) shared the highest homology with Bougainvillea bract transcriptomes. WGCNA analysis identified 12 positively correlated tissue-specific modules, of which 2 are related to bract color formation. By comparing transcriptome data and genes within these specific modules against the KEGG database, a total of 321 unigenes associated with bract color formation in Bougainvillea were discovered. Among these, 220 unigenes are involved in anthocyanin synthesis, 43 unigenes are involved in betalain synthesis, 23 unigenes are annotated as Chlorophyll a-b binding protein genes, and 35 unigenes participate in carotenoid synthesis. Quantitative real-time PCR (qRT-PCR) validation of 16 differentially expressed genes (DEGs) including PAL2, CHS1, ANS, BZ1, 6GT, CDOPA5GT, ANR, CHS2, and DOPA, revealed significant expression differences among magenta, yellow, white, and cherry-colored bracts, suggesting their potential as candidate genes for bract color development. This study not only enriches the transcriptomic data of Bougainvillea but also identifies genes associated with bract coloration, providing a valuable theoretical basis for future gene cloning, genetic engineering, and breeding efforts in Bougainvillea.

Spectral Unmixing of Pigments on Surface of Painted Artefacts Considering Spectral Variability

Abstract. Painted artefacts, such as murals and paintings, are the treasures of human civilization. Pigment is an important component of their surfaces. It is crucial to study the composition and proportion of pigments on the surface of painted artefacts for the field of heritage conservation. In this study, hyperspectral remote sensing was used to invert the abundance of mixed pigments by spectral unmixing. Spectral variability effects are often present in hyperspectral images. Hyperspectral images of cultural artefacts also suffer from spectral variability due to factors such as particle size and impurities within the pigment, and acquisition conditions. Therefore, spectral variability was incorporated into the Linear Mixed Model of the pigment spectral unmixing. The unmixing methods are classified into two categories based on whether or not spectral libraries are used. In the experiment, computer synthesized data and laboratory-made sample blocks of mixed pigments, which mixed with different ratios of Azurite and Malachite, were selected as validation data. Five commonly used algorithms for solving the spectral variability problem, namely MESMA, Fractional Sparse SU, ELMM, RUSAL, and BCM, are used for pigment unmixing and compared with FCLS, which does not consider spectral variability. The results show that ELMM has the highest unmixing accuracy of aRMSE and xRMSE compared to other methods. At the same time, it can be seen from the metric of SAM that ELMM is able to extract reliable endmember variability spectral, which is more suitable for solving the problem of spectral variability in pigment unmixing. Finally, we apply ELMM to real artefacts Yungang Grottoes mural paintings, and obtain a lower xRMSE than FCLS, which improves the unmixing accuracy.

Adaptive superpixel segmentation and pigment identification of colored relics based on visible spectral images

This work explores the extraction of the spatial distribution and chemical composition information of pigments in colored relics through visible spectral images. An adaptive superpixel segmentation method is proposed to extract the spatial distribution information of pigments. Quadtree decomposition is applied to generate nonuniform initial seed points based on the image homogeneity. These seed points are used as the initial cluster centers in an extended simple linear iterative clustering (SLIC) algorithm for visible spectral images to create superpixels of varying sizes that reflect the homogeneity. Each superpixel is subsequently treated as an individual area in the colored relics, and a pigment identification method based on the visible spectral reflectance is proposed to identify the pigments in these areas. A standard reference database is constructed using samples that simulate the painting process of ancient wall paintings in the Mogao Grottoes. Geometric features, which are characterized by the linear combination of the normalized visible spectral reflectance, its slope and its curvature, are designed to represent the chemical composition of pigments. The geometric features of the superpixels are compared with those of the pigments in the database using the Euclidean distance to determine the pigments in each area of the colored relics. This work is expected to provide scientific guidance for pigment selection in the color restoration of colored relics.

Coloring Multilayer Zirconia May Affect Its Optical and Mechanical Properties

The coloring process of monolithic dental zirconia caused considerable debate on the possible effects of different coloring methods. The main objective of this study was to investigate the influence of pigments in 3 multilayer 5-mol% yttria partially stabilized zirconia (5Y-PSZ) disks (Lava Esthetic A2 [Zr-AGG_A2] and Bleach [Zr-AGG_BL], both 3M Oral Care, and Katana STML A2 [Zr-NoAGG], Kuraray Noritake). The influence of pigment addition on the translucency parameter (TP00), fracture toughness, Vickers hardness, biaxial strength, and hydrothermal stability was assessed and correlated with the microstructure and phase composition. The pigment composition and distribution were evaluated by light and fluorescence microscopy, electron probe microanalysis, and nano–scanning electron microscopy. The chemical and phase composition and aging behavior were assessed using X-ray fluorescence and X-ray diffraction, respectively, while the aging sensitivity of the pigments was evaluated using micro-Raman spectroscopy. In contrast to Zr-NoAGG, possessing a typical 5Y-PSZ microstructure, the pigment additions in both Zr-AGG_A2/BL zirconia resulted in large yellow and blue fluorescent Er-, Hf-, and Al-containing agglomerates composed of small grains (0.57 µm and 0.38 µm, respectively, vs. 0.92 µm for the surrounding grains) with lower Y2O3 content. Zr-AGG_A2 had the lowest aging resistance, with transformation degradation occurring exclusively within the pigment agglomerates. All zirconia grades had a high Y2O3 content (4.2%–5.7 mol%) tetragonal ZrO2 phase and a high (42%–55 wt%) cubic ZrO2 phase content. Although no statistical differences were measured for hardness and toughness, Zr-NoAGG had a significantly higher TP00, higher flexural strength, and lower mechanical reliability compared to both Zr-AGG_A2/BL zirconia. The rare-earth oxide-containing zirconia agglomerates that were added as pigments to the multilayered monolithic Zr-AGG_A2/BL zirconia are the cause for their lower optical and mechanical properties and reduced aging resistance.

Zinc Nano and Zinc Ethylenediaminetetraacetic acid (EDTA) Mediated Water Deficit Stress Alleviation in Pearl Millet (Pennisetum glaucum (L.) R. Br.): Photosystem II Electron Transport and Pigment Dynamics

Water stress adversely affects the photosynthetic apparatus and pigment composition in plants, leading to reduced yields and compromised plant health. Zinc (Zn) foliar spray in nano form presents a potential solution to ameliorate water deficit stress. We attempt here a detailed dissection of electron transport in Photosystem II (PSII) through studies on chlorophyll a fast fluorescence kinetics and non-photochemical quenching (NPQ) and pigment dynamics in response to water stress. We also investigated the possible changes in these processes and the regulation of it by Zn Nano and Zn Ethylenediaminetetraacetic acid (EDTA) foliar sprays that may lead to amelioration of stress. Our results indicated that water stress created a "traffic jam" like situation in the electron transport system of Photosystem II, leading to decreased photosynthetic efficiency. Treatments with Water deficit stress + Zn Nano (particle size < 90 nm) spray with Zn concentration at 20 mg L−1 and Water deficit stress + Zn EDTA spray (solid material size ∼ 100 mm) with Zn concentration at 240 mg L−1 effectively ameliorated water deficit stress by its action on flux ratio parameters viz., quantum yield for electron transport (φE0), probability of electron transport beyond QA (ψ0) and quantum yield of electron transport from QA⁻ to PS1 end electron acceptors (ϕR0) and also the specific fluxes and phenomenological fluxes. These treatments positively influenced chlorophyll content, and xanthophyll components, including violaxanthin, antheraxanthin, and zeaxanthin, and reduced NPQ and the de expoxidation state. Higher concentrations of Zn Nano foliar spray (water stress + Zn Nano spray Zn @ 30 mg L⁻¹) did not ameliorate water deficit stress as effectively as the lower concentrations, although this higher concentration was not in any way toxic. This lack of stress amelioration at higher concentrations of Zn Nano spray may be due to physiological limitations of elemental zinc action within the plant. Our findings suggest that Zn foliar sprays in Nano and EDTA form at optimum concentrations can significantly improve plant resilience to water stress.

Metataxonomy and pigments analyses unravel microbial diversity and the relevance of retinal-based photoheterotrophy at different salinities in the Odiel Salterns (SW, Spain)

Salinity has a strong influence on microorganisms distribution patterns and consequently on the relevance of photoheterotrophic metabolism, which since the discovery of proteorhodopsins is considered the main contributor to solar energy capture on the surface of the oceans. Solar salterns constitute an exceptional system for the simultaneous study of several salt concentrations, ranging from seawater, the most abundant environment on Earth, to saturated brine, one of the most extreme, which has been scarcely studied. In this study, pigment composition across the salinity gradient has been analyzed by spectrophotometry and RP-HPLC, and the influence of salinity on microbial diversity of the three domains of life has been evaluated by a metataxonomic study targeting hypervariable regions of 16S and 18S rRNA genes. Furthermore, based on the chlorophyll and retinal content, we have estimated the relative abundance of rhodopsins and photosynthetic reaction centers, concluding that there is a strong correlation between the retinal/chlorophyll a ratio and salinity. Retinal-based photoheterotrophy is particularly important for prokaryotic survival in hypersaline environments, surpassing the sunlight energy captured by photosynthesis, and being more relevant as salinity increases. This has implications for understanding the survival of microorganisms in extreme conditions and the energy dynamics in solar salter ponds.

Minimizing the cobalt content in black ceramic pigments by Design of Experiments

This paper presents a comprehensive optimization strategy for the synthesis of new black ceramic pigments with low cobalt content while maintaining a single-phase spinel structure. The aim is to achieve comparable hues to those of an industrial benchmark containing five transition metals while minimizing the environmental impact. Exploring all possible compositions deriving from a five–component system (Cr, Mn, Fe, Co and Ni), through traditional methods would be extremely time consuming to guarantee an efficient sampling, requiring high experimental efforts. Hence, to identify the best black compositions, we employed a chemometric approach, the Design of Experiments, aiming to investigate the compositional domain derived by varying the metals stoichiometry within fixed boundaries to identify optimal pigment compositions. The resulting pigments (comprising Cr, Fe and Co), despite the lower cobalt content, exhibited optimal colorimetric properties comparable to the standard benchmark, with experimental ΔE values comparable to the ones predicted by the model. In particular, the pure spinels Cr1.05Fe1.05Co0.9O4 and Cr1.2Fe1.05Co0.75O4 displayed low lightness and chroma (L∗ = 2.4; C∗ = 5 and L∗ = 1.12; C∗ = 1.1, respectively), providing deep and dark black tonality. These compositions exhibit promising colorimetric performance and chemical stability, offering potential benefits for industrial applications.

Exploring the interplay between phytoplankton taxonomy, pigments, and optical properties in Ratnagiri coastal waters using a multi-parameter approach

This study presents a comprehensive analysis of phytoplankton diversity and optical properties in the coastal waters of Ratnagiri, India. Ratnagiri, located on the southern coast of Maharashtra, is one of the major centre for fishing activities in India as well as a developing hub for industrial activities. Given its ecological significance and the pressures it faces, the coastal waters of Ratnagiri present a valuable case for studying phytoplankton dynamics and their light absorption properties. We integrated parameters like phytoplankton taxonomy, pigment composition, Coloured Dissolved Organic Matter (CDOM), and phytoplankton absorption characteristics to give a comprehensive view of the phytoplankton community and its optical environment. Phytoplankton samples from Ratnagiri were analyzed with microscopy and high-performance liquid chromatography (HPLC) for taxonomy and pigment profiling, while CDOM and absorption properties were measured using spectrophotometry. Our findings reveal more or less spatial uniformity in phytoplankton composition (Pielou's Evenness Index (J’) ranged between 0.84 and 0.9), with significant diversity (Shannon Diversity Index (H’) ranged from 3.7 to 4.19) within the phytoplankton community. Pigment analysis revealed key marker pigments associated with various phytoplankton classes including bacillariophytes (diatoms), chlorophytes, cyanophytes, haptophytes and cryptophytes, providing insights into community structure. Concurrently, CDOM absorption coefficient (aCDOM (440)) that ranged between 0.08 and 0.3 m−1 indicated varying levels of dissolved organic matter, influencing light absorption and availability within the water column. The phytoplankton absorption data highlighted the specific wavelengths most affected by phytoplankton presence, notably those contributed by diatoms and cyanophytes, providing insights into the optical properties of Ratnagiri's coastal waters. This integrative approach underscores the importance of considering multiple parameters to accurately assess phytoplankton dynamics and their impact on the aquatic environment. The results contribute to a better understanding of the ecological processes governing coastal waters in Ratnagiri and offer valuable information for future monitoring and management efforts.

Pulp colour and pigment composition have no genetic correlation with seed hardness in guava (Psidium guajava L.)

ABSTRACT Guava (Psidium guajava L.) is a ‘super fruit’, also known as the ‘apple of the tropics’. This study was conducted on five guava parents and their 42 F1s. They were studied for their pigment composition (lycopene, total anthocyanin, and total carotenoid content) and seed-based parameters (seed hardness, index, length, and width). Transgressive segregation was present for pigment composition, seed index, and seed hardness. For lycopene and total carotenoids content, F1s had maximum values. However, for total anthocyanins content, only guava parent BG had a considerably higher value (8.881 mg/100 g) and had a purple pulp colour. Most F1s belonged to the soft seed category (28 F1s out of 42) and intermediate seed index 1–1.5 g (24 F1s out of 42). The findings indicate that, in guava, pulp colour is not correlated with seed hardness. However, a significantly positive correlation between seed hardness and other seed-related parameters (namely seed index, seed length, and seed width) indicates that a bigger seed size is associated with seed hardness.

Growth, Biochemical Traits, Antioxidant Enzymes, and Essential Oils of Four Aromatic and Medicinal Plants Cultivated in Phosphate-Mine Residues.

Revegetation emerges as a promising approach to alleviate the adverse impacts of mining residues. However, it is essential to evaluate the characteristics of these materials and select suitable plant species to ensure successful ecosystem restoration. This study aimed to investigate the effects of phosphate-mine residues (MR) on the growth, biochemical properties, and essential oil concentration of Rosmarinus officinalis L., Salvia Officinalis L., Lavandula dentata L., and Origanum majorana L. The results showed that R. officinalis L. appeared to be particularly well-suited to thriving in MR soil. Our finding also revealed that L. dentata L., O. majorana L., and S. officinalis L. grown in MR exhibited significantly lower growth performance (lower shoot length, smaller leaves, and altered root structure) and higher antioxidant activities, with an alterations of photosynthetic pigment composition. They showed a decrease in total chlorophylls when grown on MR (0.295, 0.453, and 0.562 mg g-1 FW, respectively) compared to the control (0.465, 0.807, and 0.808 mg g-1 FW, respectively); however, they produced higher essential oil content (1.8%, 3.06%, and 2.88%, respectively). The outcomes of this study could offer valuable insights for the advancement of revegetation technologies and the utilization of plant products derived from phosphate-mine residues.

Impact of Neurotransmitters on the Fatty Acid Composition and the Pigments of the Green Microalga Scenedesmus quadricauda

Apart from their functions in the nervous system of animals, neurotransmitters operate as regulatory agents and signals in diverse kingdoms of life. Some neurotransmitters have recently been revealed to exert specific effects on microalgae, predominantly functioning as algal growth stimulators. This article presents new data on the effects of such neurotransmitters as serotonin, norepinephrine, dopamine, histamine, and acetylcholine on the fatty acid and pigment composition of the green microalga Scenedesmus quadricauda (Turp.) Breb. K-1149. It was established that acetylcholine and, to a lesser extent, histamine increased the total fatty acid content of S. quadricauda cells, whereas serotonin and dopamine decreased the fatty acid content. Acetylcholine, histamine, and norepinephrine elevated the percentage of polyunsaturated fatty acids; in contrast, serotonin and dopamine increased the share of saturated fatty acids. Acetylcholine and, to a lesser extent, norepinephrine increased the total chlorophyll content per gram of dry weight in S. quadricauda, while histamine decreased the chlorophyll content. Histamine also increased the chlorophyll a/chlorophyll b and carotenoid/chlorophyll ratios, which were decreased by dopamine. The data obtained are of biotechnological and ecological interest. The stimulation of fatty acid accumulation and the increase in the percentage of polyunsaturated species was caused by the neurotransmitters acetylcholine and histamine at low (1–10 μM) concentrations, which potentially enables facilitating the biotechnological production of health-promoting preparations for therapeutic and cosmetic purposes. However, other neurotransmitters (dopamine and serotonin) tested increased the relative content of saturated fatty acids; therefore, they apparently can be used to stimulate biofuel production, since saturated fatty acid-rich lipids are advantageous raw materials for biodiesel production. The impact of neurotransmitters on microalgal fatty acid composition and photosystem components may be considered in terms of ongoing chemical interaction between microalgae and other aquatic ecosystem components that are known to produce neurotransmitters.

Comparison of the Characteristics of Baekak(chalk) and Hobun(shell) Pigment for Dancheong based on Natural Raw Materials

Calcium carbonate white pigments were manufactured by classifying them into Baekak(chalk) and Hobun(Shell) according to the type of natural raw material, and their material characteristics were analyzed. Their performances were compared by evaluating their weather resistance, antifungal activity, and flame retardancy. The main components of Baekak pigments are calcite and dolomite, and those of Hobun pigments a re calcite and a ragonite. Depending on the raw material, the specific factors identified are Mg from the mineral composition of Baekak pigments, and P and S from the protein composition of Hobun pigments. The particle shape of the pigment shows a crystal structure unique to minerals in the case of Baekak pigments, but the Hobun pigments are classified into plate-shaped or columnar structures depending on the raw material and are in an aggregated state with a large specific surface area. While the absorption amount of Baekak pigments made from limestone and dolomite is similar, that of Hobun pigments shows differences depending on the raw material, with the absorption amount being high in the order of oyster &gt; cockle &gt; clam. As a result of the color analysis, both the Baekak and the Hobun pigments had L* values of over 90 and opacity of over 90, indicating good whiteness and painting workability. As a result of the accelerated weathering test, the final color difference value(ΔE) was less than 2.02, which was difficult to recognize with the naked eye, and the Hobun pigment showed superior color and film stability compared to the Baekak pigment. As a result of the antifungal test, all calcium carbonate-based white pigments showed high preventive effects against decay fungi, and among them, the pigment made from clams and cockles showed excellent antiseptic properties. In addition, the pigment made from clams and cockles has been shown to have flame retardant properties, and it is expected that it will contribute to enhancing the preservation of organic cultural heritage when applied to it.

The effect of ship-induced wave trains on periphytic algal communities in the littoral zone of a large regulated river (River Danube, Austria)

Riverine ecosystems are profoundly influenced by hydrological dynamics and natural flow regimes, which dictate the temporal variability of water levels and the amplitude of fluctuations. Human activities, particularly navigation and hydropower generation, have significantly altered these natural patterns, leading to detrimental impacts on the physical, chemical, and biological integrity of river ecosystems. The littoral zone, in particular, is highly susceptible to anthropogenic disturbances, experiencing disruptions in biological activity and biogeochemical processes. This study evaluates the effects of ship-induced wave trains on the structural and functional properties of periphytic algal communities in a regulated river environment. Using data from the Austrian Danube River, periphytic algae's immediate and long-term responses to wave events generated by different types of ships were investigated. Immediate reactions of periphytic algae to wave trains were characterized by reductions in the effective quantum yield of PS II, indicating stress-induced down-regulation of photosystem II photochemistry. Abrasion and remobilization of periphytic algae due to wave action led to increased resuspension of chlorophyll-a into the water column. Furthermore, ship-induced wave trains influenced the pigment composition of periphyton, with photoprotective mechanisms being activated in response to fluctuating light conditions. Long-term effects of wave impact on periphytic algae biomass varied depending on water depth and exposure to aerial stress. While wave action mitigated desiccation stress in shallow areas, it resulted in biomass reduction and alterations in community composition in deeper zones. Notably, the occurrence of diatoms decreased in wave-impacted areas, potentially shifting the community towards Chlorophyceae dominance. Overall, this study underscores the complexity of ship-induced wave impacts on riverine ecosystems and highlights the importance of considering both immediate and long-term responses of periphytic algal communities. Understanding these dynamics is crucial for informing sustainable management strategies aimed at mitigating the adverse effects of navigation activities on riverine biodiversity and ecosystem functioning.

ASPECTS ON PRESERVING WALL PAINTINGS (EXAMPLE OF UKRAINE AND CHINA)

Analysis of tested restoration methods and their effects on historical fresco restoration cycles emphasized the specification of previous achievements and losses in the restoration industry. As examples, the wall paintings of the Dunhuang sanctuaries in China and the Trinity Gate Church in Kyiv were analyzed. Based on modern comprehensive research, periodic photo documentation and scientific monitoring of the monument, the main factors influencing the preservation of the mural of the Trinity Gate Church have been identified in the context of studying the problems of the current state of monumental painting. With a perspective on the development of heritage preservation measures and recommendations for further conservation, the study aims to determine the most effective ways to maintain the artwork's original state. The original chemical composition of the mineral pigments of the sanctuaries of Dunhuang and the Trinity Gate Church was determined. The common problems of the state of emergency for the wall paintings of Dunhuang and the Trinity Gate Church are outlined.

Unraveling the Genetic Control of Pigment Accumulation in Physalis Fruits.

Physalis pubescens and Physalis alkekengi, members of the Physalis genus, are valued for their delicious and medicinal fruits as well as their different ripened fruit colors-golden for P. pubescens and scarlet for P. alkekengi. This study aimed to elucidate the pigment composition and genetic mechanisms during fruit maturation in these species. Fruit samples were collected at four development stages, analyzed using spectrophotometry and high-performance liquid chromatography (HPLC), and complemented with transcriptome sequencing to assess gene expression related to pigment biosynthesis. β-carotene was identified as the dominant pigment in P. pubescens, contrasting with P. alkekengi, which contained both lycopene and β-carotene. The carotenoid biosynthesis pathway was central to fruit pigmentation in both species. Key genes pf02G043370 and pf06G178980 in P. pubescens, and TRINITY_DN20150_c1_g3, TRINITY_DN10183_c0_g1, and TRINITY_DN23805_c0_g3 in P. alkekengi were associated with carotenoid production. Notably, the MYB-related and bHLH transcription factors (TFs) regulated zeta-carotene isomerase and β-hydroxylase activities in P. pubescens with the MYB-related TF showing dual regulatory roles. In P. alkekengi, six TF families-bHLH, HSF, WRKY, M-type MADS, AP2, and NAC-were implicated in controlling carotenoid synthesis enzymes. Our findings highlight the intricate regulatory network governing pigmentation and provide insights into Physalis germplasm's genetic improvement and conservation.