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Sunflecks are transient patches of direct radiation that provide a substantial proportion of the daily irradiance to leaves in the lower canopy. In this position, faster photosynthetic induction would allow for higher sunfleck-use efficiency, as is commonly reported in the literature. Yet, when sunflecks are too few and far between, it may be more beneficial for shade leaves to prioritize efficient photosynthesis under shade. We investigated the temporal dynamics of photosynthetic induction, recovery under shade, and stomatal movement during a sunfleck, in sun and shade leaves of Fagus sylvatica from three provenances of contrasting origin. We found that shade leaves complete full induction in a shorter time than sun leaves, but that sun leaves respond faster than shade leaves due to their much larger amplitude of induction. The core-range provenance achieved faster stomatal opening in shade leaves, which may allow for better sunfleck-use efficiency in denser canopies and lower canopy positions. Our findings represent a paradigm shift for future research into light fluctuations in canopies, drawing attention to the ubiquitous importance of sunflecks for photosynthesis, not only in lower-canopy leaves where shade is prevalent, but particularly in the upper canopy where longer sunflecks are more common due to canopy openness.

The content and ratio of plastid pigments in the conifers of three species of the larch genus (Larix Mill.) were studied: Siberian larch (L. sibirica Ledeb.), Gmelin’s larch (L. Gmelinii (Rupr.) Rupr.), Sukachev’s larch (L. Sukaczewii Dylis). Their seed progeny is concentrated on a pilot site in the Sergachsky forestry of the Nizhny Novgorod region with geographical coordinates 55°32 ‘14,2” N 45°28’01,0” E and an absolute height of 160 m. The site is assigned to the zone of coniferous-broad-leaved forests (the third forest-growing zone) and is included in the area of coniferous-broad-leaved (mixed) forests of the European part of the Russian Federation. The content of chlorophyll a, chlorophyll b and carotenoids in the needles was determined by spectrophotometric method at wavelengths: 665 nm, 649 nm, 452,5 nm. Samples for research were prepared in accordance with the principle of a single logical difference and randomized sample formation. Phenotypic differences in the pigment composition of needles between representatives of these species were revealed. The pigment composition of Siberian larch is dominated by chlorophyll a (3,76 ± 0,12 mg/g), significantly less chlorophyll b (1,87 ± 0,07 mg/g) and even less carotenoids (0,59 ± 0,02 mg/g). The same is observed in the pigment composition of other larch species. The hereditary conditionality of the species specificity of Siberian larch, Gmelin’s larch and Sukachev’s larch was established for all the tested characteristics. The greatest influence (29,84 ± 1,61 %) on the formation of the total phenotypic dispersion was observed in the ratio of the content of chlorophyll-a to the content of carotenoids, the least (5,89 ± 2,16 %) — in the content of dry matter in the needles. Relatively high values were obtained for the proportion of carotenoids (26,74 ± 1,68 %) and the ratio of their content to the total of chlorophylls (26,39 ± 1,69 %). The studied species showed an unequal level of similarity or significant differences in the individual characteristics of the pigment composition of needles.

Plants acclimate to fluctuations in light conditions by adjusting their photosynthetic apparatus. When the light intensity exceeds, an unbalanced excitation of the two photosystems occurs. It results in reduced photosynthetic efficiency. Photosystem II (PSII) is the most susceptible and dynamically regulated part of the light reactions in the thylakoid membrane. Non-photochemical quenching of chlorophyll fluorescence (NPQ) is one of the short-term photoprotective mechanisms, which consist of the number of components. The strongest NPQ component — qE is localized in the PSII antenna and induced in plants by lumen acidification, the activation of the pH sensor PsbS, and the conversion of the violaxanthin to zeaxanthin within the xanthophyll cycle. Here, I present data that characterizes the role of the PsbS protein in organization of PSII structural components in isolated PSII-enriched membranes. The preparations were isolated from wild-type (WT) and PsbS-less (PsbS-KO) mutant rice plant. Based on the obtained results, the PSII-enriched membranes from WT and PsbS-KO differ as in the level of lipids, also in carotenoids. I conclude that the PsbS-dependent changes in membrane fluidity in PsbS-KO mutant plants compensated with increased lipid level in mutant plants.

The effects of different types of ultraviolet (UV) radiation (UVR, wavelength=280–400 nm) and light intensities on cell growth, pigment composition, UV-absorbing compounds (UVACs), and chlorophyll a (Chl a) fluorescence were studied in dinoflagellate Prorocentrum lima cultured outdoors for 16 days and indoors for 18 days. In the outdoor experiment, UVA radiation (320–400 nm) increased the growth rate of this dinoflagellate when solar light intensities were 12%. Exposure to UVB radiation (280–320nm) alleviated the negative effects of UVA. In the indoor experiment, UVA and low doses of UVB enhanced growth rates. Addition of low doses of UVB to UVA exposure resulted in higher contents of Chl a and photoprotective pigments compared with UVA exposure only. The results of both experiments showed that UVB is the primary signal of UVAC synthesis. High-dose UVB exposure accelerated growth rates when UVAC contents were maintained at high levels, suggesting that the latter plays a key role in UVR damage protection. Furthermore, the repair rate was enhanced by UVB exposure after 16 days of culture. This study confirms the positive effects of UVA and UVB on the growth of P. lima, with the latter enhancing the photoprotective and recovery pathways of the species.

The stimulation of astaxanthin synthesis in Haematococcus pluvialis cells under high-intensity light in the combined action of Rose Bengal photosensitizer has been established. It was revealed that when Rose Bengal was used as an additional inducer of carotenogenesis in high-intensity light, the dry weight of the Haematococcus and the diameter of the cells in suspension increase compared to the action of only high-intensity light on algae cells. The observed increases in dry weight are significant and reach 40 % excess over control. We suggest that the increase in dry weight, Haematococcus cell diameter and astaxanthin yield when H. pluvialis photosensitizer is added to the incubation medium against the background of high-intensity light is not associated with increased stress (since the used concentrations of Rose Bengal are too small to induce photo-oxidative stress), but the signaling properties of the generated Rose Bengal singlet oxygen, which may be the primary agent in the transduction of a signal that triggers increased synthesis of astaxanthin in H. pluvialis cells.

Under natural conditions, plants constantly encounter various biotic and abiotic factors, which can potentially restrict plant growth and development and even limit crop productivity. Among various abiotic factors affecting plant photosynthesis, light serves as an important factor that drives carbon metabolism in plants and supports life on earth. The two components of light (light quality and light intensity) greatly affect plant photosynthesis and other plant’s morphological, physiological and biochemical parameters. The response of plants to different spectral radiations and intensities differs in various species and also depends on growing conditions. To date, much research has been conducted regarding how different spectral radiations of varying intensity can affect plant growth and development. This review is an effort to briefly summarize the available information on the effects of light components on various plant parameters such as stem and leaf morphology and anatomy, stomatal development, photosynthetic apparatus, pigment composition, reactive oxygen species (ROS) production, antioxidants, and hormone production.

Oligotrophic bogs prevail among wetlands in the mainland of the North of Russia. The study of the moss cover response to the increase in anthropogenic load makes it possible to reveal a shift in the ecological balance of bog ecosystems. The goаl of the research is to reveal changes in the pigment apparatus of the moss cover under drainage, road construction and mining operation as in the case of the Arkhangelsk region. Sphagnum fuscum (Schimp.) H. Klinggr. was used as the main object for studying the pigment composition of the photosynthetic apparatus. A change in the pigment composition during the drainage of bogs was found when comparing the pigments of S. fuscum moss on the undisturbed Ilas bog massif and the drained bog massif “Ovechye”; the content of carotenoids decreases and the content of chlorophyll a increases. The influence of the traffic load was studied in an open wetland of the Mezen district, where there is no tree-shrub layer. Succession of dominant species is observed in the moss-lichen layer of the bog in the immediate vicinity of the road (34 m); the projective cover of sphagnum mosses decreases to less than 10 %, and brie mosses emerge as dominants. The content of all analyzed pigments in moss samples increases with the distance from unpaved roads, especially the content of chlorophylls (>5 times at a distance of 100 m and more). As an example of the anthropogenic impact of a mining enter prise, we used terricones of the Lomonosov Mining and Processing Plant, PJSC Severalmaz, from which aeolian transport of dust particles of rocks containing saponite occurs. Near the pollution source, the content of total moss pigments is noticeably lower than in the area protected by a forest belt. A decrease in the proportion of chlorophylls a and b with a slight increase in the content of carotenoids was found in the pigment complex. The changes are due to the transfer of saponite; a clay mineral that actively absorbs water. The increased moisture provides favorable conditions for the moss vegetation, which mitigates the negative effect of pollutants on the pigment apparatus of plants. Overall, pigments content change represents plants adaptation to the adverse impacts and anthropogenic pressing.

Ice algae are key contributors to primary production and carbon fixation in the Arctic, and light availability is assumed to limit their growth and productivity. We investigated photo-physiological responses in sea ice algae to increased irradiance during a spring bloom in West Greenland. During a 14 d field experiment, light transmittance through sea ice was manipulated to provide 3 under-ice irradiance regimes: low (0.04), medium (0.08), and high (0.16) transmittances. Chlorophyll a decreased with elevated light availability relative to the control. Maximum dark-adapted photosynthetic efficiency (ΦPSII_max) showed an initially healthy and productive ice algae community (ΦPSII_max > 0.6), with ΦPSII_max decreasing markedly under high-light treatments. This was accompanied by a decrease in the light utilization coefficient (α) and photosynthetic capacity (maximum relative electron transfer rate), and a decrease in the ratio of mono- to polyunsaturated fatty acids. This was partly explained by a corresponding increase of photoprotective pigments (diadinoxanthin and diatoxanthin), and a development of mycosporine-like amino acids as identified from a distinctive spectral absorption peak at 360 nm. After 14 d, in situ fluorescence imaging revealed significant differences in ΦPSII_max between treatments of dark-adapted cells (i.e. those sampled before sunrise and after sunset), during diel cycles, with clear chronic photoinhibition in high and medium treatments. Data demonstrate the high sensitivity of spring-blooming Arctic sea ice algae to elevated irradiance caused by loss of snow cover. The predicted loss of snow cover on landfast ice will negatively impact ice algae, their potential primary production, and nutritional quality for higher trophic levels.

Photosystem II (PSII) catalyzes the light-driven oxygen-evolving reaction via its catalytic core and peripheral light-harvesting antennas. Oxyphototrophs have evolved diverse antenna systems, enabling them to adapt to different habitats. Recently, high-resolution structures of PSII-antenna supercomplexes from the green lineage (higher plants and green algae) and the red lineage (diatoms) were solved. The antenna complexes from the two lineages share similar protein folding, but differ in terms of the oligomeric states, pigment composition, and assembly patterns with the core. These differences result in distinct pigment-protein networks in PSII from different organisms. We herein summarize the similarities and differences in these structures and outline the molecular basis of the assembly, energy transfer, and regulation of the eukaryotic PSII-antenna supercomplexes.

Naturally colored cotton is a green textile material. To cultivate new colored cotton and improve its performance, we must first understand the types, composition, and formation mechanism of the pigments in colored cotton. This study aims to explore the composition and structure of cotton fiber pigments. Qualitative analyses of pigment extracts from brown cotton, green cotton, and white cotton fibers were carried out using ultraviolet spectroscopy, diagnostic agents, and liquid chromatography–mass spectrometry. The main component of cotton fiber pigments was flavonoids, and specific types of flavonoids were found in the pigments in brown cotton, green cotton, and white cotton fibers. Research on the composition of cotton fiber pigments can increase our understanding of colored cotton fibers and lay a foundation for the cultivation, planting, and development of colored cotton fibers, as well the identification of naturally colored cotton from dyed cotton.

The Jiangxue Palace is part of the imperial garden of the Imperial Museum, a world cultural heritage site. In this work, the techniques and components of its color paintings are described and analy...

The article considers the results of analysis of photosynthetic pigments сcontent (chlorophyll a, chlorophyll b, carotenoids) in birch leaves growing along the roads of Barnaul. High level of pollution causes decrease inamount of chlorophyll a and b and a change in chlorophyll a/b ratio. Carotenoids act as a protective mechanism againstthe destruction of chlorophyll a molecules and organic substances. Their number increases during the growing season.

Climacteric fruits such as papaya are characterized by changes in the pigment composition during fruit ripening. Therefore, information on the degree of fruit ripeness with respect to the pigment c...

Raman imaging allows one to obtain spatially resolved chemical information in a nondestructive manner. Herein, we present analytical aspects of effective in situ and in vivo Raman imaging of algae and cyanobacteria from within their native rock habitats. Specifically, gypsum and halite inhabited by endolithic communities from the hyperarid Atacama Desert were analyzed. Raman imaging of these phototrophic colonization reveals a pigment composition within the aggregates that helps in understanding some of their adaptation strategies to survive in this harsh polyextreme environment. The study is focused on methodical aspects of Raman imaging acquisition and subsequent data processing. Point imaging is compared with line imaging in terms of their image quality, spatial resolution, spectral signal-to-noise ratio, time requirements, and risk of laser-induced sample alteration. The roles of excitation wavelength, exposure time, and step size of the imaging grid on successful Raman imaging results are also discussed. [Figure not available: see fulltext.], This study was supported by the Czech Republic Ministry of Education, Youth and Sports under the Funding Programme INTER-COST, grant number LTC18036 (COST Action NEUBIAS,CA15124), and by grant PGC2018-094076-B-I00 from MCIU/AEI (Spain) and FEDER (UE).

H. pluvialis is a unicellular freshwater alga containing many bioactive compounds, especially carotenoids, which are the strongest antioxidants among the pigments. This study evaluates the composition and content of carotenoids and other pigments in both stages of algae life cycle, especially in the green vegetative stage, less studied in comparison to the red stage. To determine the composition and content of carotenoids, a combination of HPLC-DAD and LC-QTOF-MS was used. The content of carotenoids in the green vegetative stage was significantly lower than in the red vegetative stage. In the green vegetative stage, 16 different carotenoids and other pigments were identified. Among the total 8.86 mg g−1 DW of pigments, 5.24 mg g−1 DW or 59% of them were chlorophyll a with its derivatives, and 3.62 mg g−1 DW or 41% of them were free carotenoids. After the transition from the green to the red stage, the carotenoid composition was replaced by secondary carotenoids, astaxanthin and its esters, which predominated in the whole carotenoid composition. In addition to free astaxanthin, 12 astaxanthin monoesters, 6 diesters and 13 other carotenoids were determined. The majority of 37.86 mg g−1 DW pigments were monoesters. They represented 82% of all pigments, and their content was about 5 times higher than both, diesters (5.91 mg g−1 DW or 12% of all) and free carotenoids (2.4 mg g−1 DW or 6% of all). The results of the study contribute to the data on the overall pigment composition and content of H. pluvialis algae and provide the basis for further improvement of cultivation of the H. pluvialis algae.

Structural changes in phytoplankton communities have large influence on marine elemental cycling, food web dynamics and carbon export. Here we used data from two field expeditions, performed in spring and fall, over a coast-offshore gradient to investigate phytoplankton structure and dynamics in the Southwestern Tropical Atlantic (SWTA). Results revealed a predominant role of the thermohaline structure as the main driver of phytoplankton dynamics regardless the season. In fall, the thermocline and nutricline shallowing promoted a biomass increase, which was 3-fold higher around the oceanic islands. The structure of phytoplankton community mainly varied vertically, with Prochlorococcus pigments contributing greatly to the higher nutrient Deep Chlorophyll Maximum, whereas other Cyanophyceae predominated in nutrient poor surface layers during the two seasons. In addition, a clear coast-offshore variability in the new production (Fp) was observed, with the shelf region displaying higher values (up to 0.21), promoted by larger Bacillariophyceae pigments concentration, thus suggesting a coastal influence on shelf production. Although the phytoplankton biomass increased seasonally, our results highlighted a predominance of recycled production (Fp) and uncoupled dynamics between biomass and size of phytoplankton structure, with pico- and nanophytoplankton dominating the relative biomass, i.e., ca. 80% of the community in both seasons. We hypothesize that these patterns may result from a strong nitrogen limitation (N:P of around 3:1), which likely constrain a pronounced growth of the microphytoplankton.

Drought is one of the main environmental stress factors affecting plant growth and yield. The impact of different PEG concentrations on the photosynthetic performance of maize (Zea mays L. Mayflower) and sorghum (Sorghum bicolor L. Foehn) was investigated. The activity of the photosynthetic apparatus was assessed using chlorophyll fluorescence (PAM and JIP test) and photooxidation of P700. The data revealed that water deficiency decreased the photochemical quenching (qP), the ratio of photochemical to nonphotochemical processes (Fv/Fo), the effective quantum yield of the photochemical energy conversion in PSII (ΦPSII), the rate of the electron transport (ETR), and the performance indexes PItotal and PIABS, as the impact was stronger in sorghum than in maize and depended on drought level. The PSI photochemistry (P700 photooxidation) in sorghum was inhibited after the application of all studied drought levels, while in maize, it was registered only after treatment with higher PEG concentrations (30% and 40%). Enhanced regulated energy losses (ΦNPQ) and activation of the state transition under drought were also observed in maize, while in sorghum, an increase mainly in nonregulated energy losses (ΦNO). A decrease in pigment content and relative water content and an increase in membrane damage were also registered after PEG treatment. The experimental results showed better drought tolerance of maize than sorghum. This study provides new information about the role of regulated energy losses and state transition for the protection of the photosynthetic apparatus under drought and might be a practical approach to the determination of the drought tolerance of plants.

Broad application of CuO nanoparticles (CuO-NP) for industrial and household purposes leads to a continuous increase in their discharge to, and, hence, ever-increasing environmental hazards for aquatic ecosystems. Microalgae-based technologies hold promise for bioremediation of diverse hazardous micropollutants (HMP), including NP, from wastewater. In this study, we tested the ability of the green microalga Desmodesmus sp. to accumulate CuO-NP or their components. We also assessed the tolerance of this microalga to the environmentally relevant concentrations of CuO-NP. Using scanning electron microscopy, we demonstrated that the average size of CuO-NP was 50–100 nm, and their purity was confirmed with elemental composition analysis. Tests of the colloidal suspensions of CuO-NP showed that the hydrodynamic diameter of CuO-NP and their aggregates was below 100 nm. Flow cytometry analysis showed that CuO-NP at a concentration of 100 µg L−1 slightly inhibited the viability of microalgae cells and led to an increase in their oxidative stress. The assessment of the condition of photosystem II showed that CuO-NP exert a multifaceted effect on the photosynthetic apparatus of Desmodesmus sp., depending on the concentration of and the exposure to the CuO-NP. Desmodesmus sp. turned to be relatively tolerant to CuO-NP. In addition, the ICP-MS method revealed increased bioaccumulation of copper by microalgae cells in the experimental groups. The outcomes of this study indicate that the Desmodesmus sp. has a significant potential for bioremoval of the copper-based nanostructured HMP from an aquatic environment.

Phaeocystis globosa is a nuisance haptophyte species that forms annual blooms in the southern North Sea and other coastal waters. At high biomass concentration, these are considered harmful algal blooms due to their deleterious impact on the local ecosystems and economy, and are considered an indicator for eutrophication. In the last two decades, methods have been developed for the optical detection and quantification of these blooms, with potential applications for autonomous in situ or remote observations. However, recent experimental evidence suggests that the interpretation of the optical signal and its exclusive association with P. globosa may not be accurate. In the North Sea, blooms of P. globosa are synchronous with those of the diatom Pseudo-nitzschia delicatissima, another harmful bloom-forming species with similar pigmentation and optical signature. Here we combine new and published measurements of pigmentation composition and inherent optical properties from pure cultures of several algal and cyanobacterial groups, together with environmental spectroscopy data, to identify the pigments generating the optical signals captured by two established algorithms. We further evaluate the association of those pigments and optical signals with P. globosa. We found that the interpretation of the pigment(s) generating the optical signals were incorrect and that previous methods are not specific to P. globosa, even in the context of the phytoplankton assemblage of the southern North Sea. Additionally, we found that the optical and pigment signatures of Phaeocystis species are part of a broad pigmentation trend across unrelated taxonomic groups related to chlorophyll c3 presence, with important consequences for the interpretation of pigment and optical data. We then develop and evaluate an algorithm to detect this pigmentation pattern with minimal influence of co-occurring species and elaborate general recommendations for the future development of algorithms.

The purpose of this study was to characterize and quantify the chemical constituents of heartwood and sapwood of Dalbergia oliveri extract in order to investigate the chemical components that determine the formation of heartwood’s color. In this work, the types of pigments in heartwood and sapwood extract were analyzed using UV-Visible (UV) Spectrophotometer, and the main pigment components of heartwood and sapwood extract were identified and quantified using ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS). The results showed that the difference in content of the main components between heartwood and sapwood of Dalbergia oliveri was slight, and the lignin structure between heartwood and sapwood is basically identical; flavonoid pigments were found to be the primary chromophoric components of heartwood and sapwood extract. However, a total of 21 flavonoids were identified in heartwood and sapwood, of which the unique substances to heartwood were vitexin, isorhamnetin, and pelargonidin, and the content of isoliquiritigenin, formononetin, and biochanin A were 253, 37, and 583 times higher in the heartwood than in the sapwood, respectively, which could be the main pigment components affecting the significant color difference between heartwood and sapwood of Dalbergia oliveri. These results will provide a foundation for revealing the underlying mechanism of color difference between heartwood and sapwood and provide a theoretical basis for wood coloring.

Red and yellow pigments are the major ingredients of safflower, often used to color food and cosmetics. Carthamin, the main component of red pigment, and hydroxysafflor yellow A, anhydrosafflower yellow B were representative components of yellow pigment. Plant metabolomics and semi-quantitative analysis were used to analyze the changes of pigment composition during blooming period, especially these characteristic components. Carthamin, hydroxysafflor yellow A, anhydrosafflower yellow B and other components were screened out as differential metabolites based on plant metabolomics. Then semi-quantitative analysis was used to quantify these three representative components of pigments. Experimental results showed that: content of pigments has dynamic changes along with flowering, in the early blooming period, yellow pigment accumulated much and red pigment was low in content. In the middle period, the accumulation rate of the yellow pigment slowed down and content was stabilized. In the next step, the content of yellow pigment gradually decreased, and the content of red pigments gradually increased. Later, the level of yellow pigment decreased significantly, and accumulation rate of red pigment increased significantly. Lastly, the appearance color of safflower was red, with yellow parts barely visible, and accumulation of red pigment was highest, yellow pigment was lowest in content. This article is protected by copyright. All rights reserved.

According to field observations during 1995–2005 and 2012–2016, the pigment composition of phytoplankton in the Upper Volga reservoirs is given. With an average Chl a content of 13,1±1,4 to 52,5±2,7 μg/L in the Ivankovo reservoir and from 4,1±0,9 to 27,5±2,5 μg/L in the Uglich reservoir, an increase in Chl a was noted after an abnormally hot 2010. The content of Chl a in the Ivankovo reservoir retaining eutrophic status does not go beyond the limits of long-term fluctuations. In the Uglich reservoir, an increase in the absolute and relative amount of Chl a was revealed, indicating the transition of the reservoir to the eutrophic category.

The content of astaxanthin, including its mono- and diesters, and photosynthetic pigments, has been analyzed in cells of H. pluvialis strain IBCE-H17 under the combined prolonged action of several inducers of astaxanthin accumulation. The effective induction of the astaxanthin accumulation, mainly in the form of monoesters of fatty acids, was shown after a 20-day cultivation under high-intensity light and with the addition of 1-2 g/l of sodium acetate to the culture medium. A simultaneous decrease in the content of chlorophylls and lutein in the H. pluvialis cells was observed under these conditions. The use of sodium acetate in combination with sodium chloride did not lead to noticeable changes in the content of astaxanthin compared with the use of sodium acetate alone. The obtained data can be helpful in the biotechnological production of Haematococcus biomass enriched with economically valuable compounds. astaxanthin, Haematococcus pluvialis, pigments, sodium acetate, sodium chloride, high-intensity light. This work was supported by Grant no. Б19РМ-010 of the Belarusian Republican Foundation for Fundamental Research and Grant no. 19-54-04003 of the Russian Foundation for Basic Research.

Fresh-cut yam (Dioscorea opposita) slices brown easily and can turn yellow under certain storage conditions. The formation conditions of yellow pigment, pigment composition, and quality of yellow fresh-cut yam slices were investigated in this study. The results showed that storage temperature, gas ratio of packaging, and slice thickness affected the formation of yellow pigmentation. The highest content of yellow pigment was found in 0.1 cm-thick yam slices stored at 25 °C for 18 h and packaged in 20% O2 and 80% N2. Yellow pigments were composed primarily of bisdemethoxycurcumin (73.7%) and two other unknown compounds that were not attributed to microorganisms. Yellow fresh-cut yam exhibited good quality, and the alcohol and ester extracts of yellow yams had higher oxygen radical adsorption capacity and 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability compared to white fresh-cut yam.

The peculiarities of the influence of LED-lighting of different spectral composition with varying ratios of physiologically significant spectral ranges on biometric parameters and the pigment composition of the leaf plate of microclonally propagated aspen (Populus tremula L.) and birch (Betula pendula Roth.) plants were identified during the adaptation ex vitro, which indicate the species specificity of plants response to the illumination spectrum.

We confirm an amnesic shellfish poisoning risk associated with domoic acid production by the species Pseudo-nitzschia plurisecta and determine the toxin profile, which includes three domoic acid isomers. Although the species was reported once in European waters, along the Spanish Atlantic coast, here we describe and characterize P. plurisecta collected during the first occurrence in French Atlantic waters. Three strains (IFR-PPL-15.1, 15.2 and 15.3) were isolated from French coastal water samples in June 2015. These strains were identified and characterized by microscopic observation, molecular (ITS region sequencing and phylogenetic analysis) and metabolite (toxins and pigments) analyses. The cell shape is lanceolate and the valve contains a central interspace with uniseriate stria of oval-square poroids, each divided into 3–10 sectors. The ITS gene sequence is homologous to the original sequence available for the Spanish strain P. plurisecta. The pigment profile contains chl a, c3, c2, fucoxanthin, diatoxanthin, diadinoxanthin and traces of β,β-carotene. Results on morphology, phylogeny and pigments led to the identification of P. plurisecta and confirmed its first occurrence in French waters.

Waters of the Southern Ocean are characterized by high macronutrient concentrations but limited availability of trace metals and light, often making it difficult for phytoplankton to achieve maximum growth rates. One strategy employed by Southern Ocean phytoplankton in culture to cope with low light and low dissolved iron (DFe) is to enhance light absorption by increasing their antenna size rather than the number of reaction centers, thereby reducing their Fe demand. Here we provide physiological evidence that natural populations of Southern Ocean phytoplankton employ a similar photoacclimation strategy to cope with low ambient DFe concentrations. During a research cruise to the Ross Sea in 2013-2014, we conducted 4 bioassay experiments in which we manipulated light and DFe concentrations and measured changes in phytoplankton biomass, growth rate, photosynthetic parameters, fluorescence parameters, and pigment composition. Phytoplankton responded strongly to DFe additions, exhibiting significantly higher biomass, growth rates, and photosynthetic competency. At low light, the maximum photosynthetic rate (P*max) was significantly reduced and the photosynthetic efficiency (α*) was unchanged compared to the high light treatment, regardless of phytoplankton species composition or DFe concentration. Our data suggest that Southern Ocean phytoplankton have evolved an Fe-saving strategy whereby they photoacclimate to low light by increasing their photosynthetic unit size, rather than photosynthetic unit number, even when DFe is available. It appears this Fe-saving strategy is characteristic of both Phaeocystis Antarctica and diatoms, suggesting that it is a common adaptation among phytoplankton taxa that grow under Fe limitation in the Southern Ocean.

Climate change impacts the characteristics of the vegetation carbon-uptake process in the northern Eurasian terrestrial ecosystem. However, the currently available direct CO2 flux measurement datasets, particularly for central Siberia, are insufficient for understanding the current condition in the northern Eurasian carbon cycle. Here, we report daily and seasonal interannual variations in CO2 fluxes and associated abiotic factors measured using eddy covariance in a coniferous forest and a bog near Zotino, Krasnoyarsk Krai, Russia, for April to early June, 2013–2017. Despite the snow not being completely melted, both ecosystems became weak net CO2 sinks if the air temperature was warm enough for photosynthesis. The forest became a net CO2 sink 7–16 days earlier than the bog. After the surface soil temperature exceeded ~1 °C, the ecosystems became persistent net CO2 sinks. To change into the full spring photosynthesis recovery, the forest is likely to need a minimum accumulated air temperature of ~80 to 137 °C, and the bog requires 141 to 211 °C. During these periods, soil temperature in the forest still remained nearly 0 °C, suggesting that it is likely that forests appear more sensitive to the rise of air temperature than bogs. Net ecosystem productivity was highest in 2015 for both ecosystems because of the anomalously high air temperature in May compared with other years. Our findings demonstrate that long-term monitoring of flux measurements at the site level, particularly during winter and its transition to spring, is essential for understanding the responses of the northern Eurasian ecosystem to spring warming.

Snow algae are photosynthetic microbes that inhabit the melting snow surface in alpine and polar regions. We analyzed the pigment and species composition of colored snow collected on Mt. Tateyama in Japan during the melting seasons of 2015 and 2016. High-performance liquid chromatographic analyses of the pigments extracted from the colored snow showed that their composition varied within the study area and were classified into four types: Type A (astaxanthin-monoester dominant), Type B (medium astaxanthin-monoester content), Type C (abundant primary carotenoids and free-astaxanthin), and Type D (abundant primary carotenoids and astaxanthin diesters). Types A and B were most commonly observed in the study area, whereas Types C and D appeared only at specific sites. Analysis of the 18S ribosomal RNA (18S rRNA) gene revealed six major amplicon sequence variants (ASVs) of snow algae, belonging to the Sanguina, Chloromonas, and Chlainomonas groups. The relative abundance of the algal ASVs showed that Sanguina was dominant (>48%) in both Types A and B, suggesting that the difference in astaxanthin abundance between the two types was caused by the production of pigments in the algal cells. The algal community structures of Types C and D differed from those of Types A and B, indicating that the primary carotenoids and astaxanthin diesters were derived from certain algal species in these types. Therefore, astaxanthin-rich Sanguina algae mostly induced the red snow that appeared widely in this alpine area; however, they were partially dominated by Chloromonas or Chlainomonas algae, causing different pigment compositions.

Photomorphogenesis is a process by which photosynthetic organisms perceive external light parameters, including light quality (color), and adjust cellular metabolism, growth rates and other parameters, in order to survive in a changing light environment. In this study we comprehensively explored the light color acclimation of Cyanobium gracile, a common cyanobacterium in turbid freshwater shallow lakes, using nine different monochromatic growth lights covering the whole visible spectrum from 435 to 687 nm. According to incident light wavelength, C. gracile cells performed great plasticity in terms of pigment composition, antenna size, and photosystem stoichiometry, to optimize their photosynthetic performance and to redox poise their intersystem electron transport chain. In spite of such compensatory strategies, C. gracile, like other cyanobacteria, uses blue and near far-red light less efficiently than orange or red light, which involves moderate growth rates, reduced cell volumes and lower electron transport rates. Unfavorable light conditions, where neither chlorophyll nor phycobilisomes absorb light sufficiently, are compensated by an enhanced antenna size. Increasing the wavelength of the growth light is accompanied by increasing photosystem II to photosystem I ratios, which involve better light utilization in the red spectral region. This is surprisingly accompanied by a partial excitonic antenna decoupling, which was the highest in the cells grown under 687 nm light. So far, a similar phenomenon is known to be induced only by strong light; here we demonstrate that under certain physiological conditions such decoupling is also possible to be induced by weak light. This suggests that suboptimal photosynthetic performance of the near far-red light grown C. gracile cells is due to a solid redox- and/or signal-imbalance, which leads to the activation of this short-term light acclimation process. Using a variety of photo-biophysical methods, we also demonstrate that under blue wavelengths, excessive light is quenched through orange carotenoid protein mediated non-photochemical quenching, whereas under orange/red wavelengths state transitions are involved in photoprotection.

Heritage : open access journal of knowledge, conservation and management of cultural and natural heritage 4(4), 4421-4438 (2021). doi:10.3390/heritage4040244 special issue: "Special Issue "Study and Characterization of Paintings: Materials, Artistic Techniques, and Conservation" / Special Issue Editors: Dr. Valeria Di Tullio, Guest Editor; Dr. Brenda Doherty, Guest Editor", Published by MDPI, Basel

We isolated a novel strain of the microalga Tetraedron minimum in Iceland from a terrestrial habitat. During long-term cultivation, a dish culture turned orange, indicating the presence of secondary pigments. Thus, we characterized T. minimum for growth and possible carotenoid production in different inorganic media. In a lab-scale photobioreactor, we confirmed that nitrogen starvation in combination with salt stress triggered a secondary carotenoid accumulation. The development of the pigment composition and the antioxidant capacity of the extracts was analyzed throughout the cultivations. The final secondary carotenoid composition was, on average, 61.1% astaxanthin and 38.9% adonixanthin. Moreover, the cells accumulated approx. 83.1% unsaturated fatty acids. This work presents the first report of the formation of secondary carotenoids within the family Hydrodictyaceae (Sphaeropleales, Chlorophyta).

Alternative pigment sources that are harmless to human health and can be produced in an eco-responsible way are of great research interest. The experiments undertaken in this study were conducted using autumn leaves of Aesculus hippocastanum as potential novel colorant sources. This study focused on improving the Gauss-peak spectra method (a less expensive alternative to high-pressure liquid chromatography) in combination with thin-layer chromatography, leading to the development of a new methodology. The collected leaves were stored at two different temperatures: 20°C and −20°C. The data obtained by spectrophotometric scanning of the samples were analyzed using the Gauss-peak spectra method in the R program with three wavelength ranges: 350–750 nm, 390–710 nm, and 400–700 nm. The results were then assessed for statistically significant differences in the estimated concentrations for the different wavelength ranges regarding (1) total pigment, carotenoid, and chlorophyll concentration (two-sample t-test) and (2) concentration of each indicated pigment (two-way analysis of variance). The results were also tested for differences between the estimated concentrations of samples stored under the different conditions. The Gauss-peak spectra results with and without thin-layer chromatography were statistically compared using a paired t-test. The results showed that thin-layer chromatography greatly enhanced the efficiency of the Gauss-peak spectra method for estimating the major and minor pigment composition without generating high additional costs. A wavelength range of 400–700 nm was optimal for all Gauss-peak spectra methods. In conclusion, the proposed method is a more successful, inexpensive alternative to high-pressure liquid chromatography.

15 pages, 8 figures, 2 tables, supplementary data https://doi.org/10.1016/j.dsr.2020.103460, The Variability of chlorophyll-specific phytoplankton light absorption [a*ph (λ)] was examined over depth and time in stratified offshore waters of the North-Western Mediterranean Sea. Coherent water patches were tracked with Lagrangian drifters during two oceanographic cruises in September (late summer) and May (post-spring bloom phase). By simultaneously analysing the phytoplankton absorption and pigment measurements, we explicitly separated the impact of pigment composition from that of pigment packaging on a*ph (λ). We further partitioned the packaging effect by comparing the variation of the packaging index [Qa*(440)], the phytoplankton community size structure (derived from diagnostic pigment analysis), and the chlorophyll-specific beam attenuation by particles [cp* (660)] as an optical index of phytoplankton photophysiology. In the ensemble of cruises, around 50% of the a*ph (440) vertical variation was explained by changes in the pigment composition (ruled by the decrease of photoprotective pigments with depth). The remaining vertical and inter-cruise variation of a*ph (440) was attributed to the packaging effect. We found that differences in the cp*(660) index (most likely indicating changes in the intracellular pigment concentration due to photoacclimation) mainly explained the observed variation in the packaging effect. Differences in cp* (660) were coincident with either the vertical gradient of light availability or the lower mean daily PAR irradiance in the euphotic layer of the September cruise. These explained the stronger packaging and lower a*ph (440) values observed with increasing depth in both cruises, and in September relative to May. On the other hand, differences in the phytoplankton community size structure did not explain the observed patterns in the packing effect. Our results highlight the importance of phytoplankton short-term acclimation to the prevailing light conditions, determining the vertical and temporal variability of a*ph (λ). A better understanding of the a*ph (λ) variability and its main drivers are key to improve different bio-optical applications, This research was funded by the successive Spanish Ministries of Science through projects SUMMER “SUrface Mixing Modulation of the Exposure to solar Radiation” (CTM 2008– 03309/MAR), BIOGAPS (CTM 2016-81008-R) and DOREMI (CTM 2012– 34294), and through the CONICET and CONICET-CSIC scholarships to G. L. Pérez. This is a contribution of the Research Group on Marine Biogeochemistry and Global Change and that of Microbial Diversity and Function in Aquatic Environments, funded by the Catalan Government. With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

7 Páginas, able olives are recognized as an essential component of the Mediterranean diet, having been explicitly included in the second level of its nutritional pyramid as an aperitif or culinary ingredient, with a recommended daily consumption of one to two portions (15–30 g). Producers demand innovative techniques improving the performance and industrial sustainability, as well as the development of new products that respond efficiently to increasingly demanding consumers. The purpose of this special issue was to publish high-quality papers with the aim to cover the state-of-the-art, recent progress and perspectives related to characterization and processing of table olives. Two reviews offer an overview about the processing and storage effects on the nutritional and sensory properties of table olives, as well as the main technologies used for olive fermentation, and the role of lactic acid bacteria and yeasts characterizing this niche during the fermentation. A total of 10 research papers cover a broad range of aspects such as characterization of their chemical composition, bioavailability, advances in the processing technology, chemical and microbiological changes, optimized use of starter cultures for the improvement of the different fermentative processes, and new strategies to reduce sodium and additives to stabilize the organoleptic properties and avoid defects., This work was funded by Spanish Government [Projects AGL RTI2018–095415–B–I00], partially financed by European regional development funds (ERDF).

Albayrak, Fazilet Özlem ( Aksaray, Yazar ), Serpentine soils are stressful for plant growth, due to nutrient deficiencies, especially Ca, low water-holding capacity, and high levels of heavy metals and Mg. Determination of biochemical differences of plants grown in serpentine and non-serpentine soil can contribute to understanding tolerance to serpentine soil. In this study, samples of three plant species (Alyssum sibiricum Willd., Salvia absconditiflora (Montbret & Aucher ex Bentham) Greuter & Burdet and Centaurea urvillei DC. subsp. stepposa Wagenitz) were compared in terms of the composition of phenolic compounds and chloroplast pigments. Higher amounts of phenolic compounds were measured in serpentine soil-grown forms of all three species. Total soluble phenolic content, in samples grown in serpentine and non-serpentine soil, respectively, S. absconditiflora 731.8 - 161.7, C. urvillei 121.0-49.7 and A. sibiricum 50.2- 47.3 µg g-1 DW). It was determined that the amount of chlorophyll a was higher in the serpentine soil grown forms of all three species while the amount of chlorophyll b was variable. In plants grown in serpentine soil, β-carotene values are higher than non-serpentine forms. Total xanthophyl values are also parallel with β-carotene findings, but lower. The findings in the present study show that antioxidant compounds such as phenolics and carotenoids may play a role in the stress tolerance of plants growing in serpentine habitats.

Mesotrione, an herbicide increasingly found in aquatic systems due to its increased application frequency in corn fields, is an inhibitor of the p-hydroxyphenylpyruvate dioxygenase (HPPD), a key enzyme for plastoquinone-9, α-tocopherol and indirectly for carotenoid biosynthesis. The direct effect of mesotrione on plastoquinone-9 and α-tocopherol synthesis and their degradation rates are well documented, but few information exists on its action on photosynthetic processes under various light intensities. We therefore investigated the photosynthetic activity, energy dissipation processes, pigment composition and α-tocopherol content when Chlamydomonas reinhardtii were exposed to mesotrione for 24 h under low light condition and then the impacts of HL treatment (75 min) were also investigated. Under low light growth conditions, mesotrione did not induce PSII photoinhihition, while substantially decreased Car:Chl-a ratio, maximal energy-dependant quenching and state 1 to state 2 transition. Under high light conditions (HL), PSII activity was highly decreased in presence of mesotrione, and the non-photochemical energy dissipation processes were drastically affected in these conditions compared to the HL treatment alone. Mesotrinone also prevent the complete recovery of PSII damage caused by HL. Light condition seems therefore to be a non-negligible factor modulating mesotrione toxicity, and this has an obvious importance in agricultural waterbodies where phytoplankton is subjected to fluctuating light intensities.

As a result of the breeding of pea peas, the yield of varieties increases, and its stability over the years decreases as a result of a decrease in their resistance to stressful environmental factors. Studies were carried out in 2006-2008 on the basis of the Orel State Agrarian University and the Research Institute of Grain-Bean and Groat Crops in the Orel Region. The article presents the results of a study on the peculiarities of the resistance of purple-flowered peas plants to stressful environmental factors (drought, diseases and pests) in the aspect of breeding for adaptability. Under dry conditions, modern purple-flowered peas had 2.3 times the number of beans and seeds, while older varieties produced 1.7 times less than normal conditions of moisture. The pigment composition (carotenoids and anthocyanins) plays important role in resistance to abiotic stressors of purple-flowered peas, and protects the plant photosystem. It has been established that modern purple-flowered peas are characterized by increased resistance to some pests (pea moth and trips), and by resistance to aphid and moth, the variety specimen UsP 98-393 was distinguished, and it can be recommended for use in breeding. Purple-flowered peas are more resistant to seed infection. The total contamination of seeds in white flowered pea varieties was at 40%, while in peples, its value was 10 times lower, and in some varieties (Natasha and Nadezhda) there was no seed damage. This is due to the accumulation of a large amount of protein inhibitors of the enzymes trypsin and chymotrypsin, the high activity of the protein inhibitors of polygalacturonase, as compared to regular peas, and the formation of a thicker (on average 7%) and massive seed coat (on average, 25 %). Purple-flowered peas have a higher environmental resistance than white-flowered varieties.

This review focuses on the diversity of French tropical overseas macroalgae and their biotechnological applications. After listing the specific diversity, i.e. 641 species in French Antilles in the Atlantic Ocean, 560 species in the Indian Ocean, and 1015 species in the South Pacific Ocean, we present the potential of their metabolites and their main uses. Among the great diversity of metabolites, we focus on carbohydrates, proteins, lipids, pigments and secondary metabolites, in particular terpenes and phenolic compounds. The main applications of reef macroalgae are described in human and animal consumptions, phycocolloids extraction, production of active ingredients for health, cosmetics, agriculture, and bioremediation. For each application, we list what has been done, or will be done in French tropical overseas territories and point out the challenges faced when using this chemo-diversity, and problems linked to their exploitation. Finally, we discuss challenges to develop seaweed farming, their uses in carbon sequestration and resilience to global change, their uses for alternative proteins together with the production of bioenergy and biomaterials. As a conclusion, we encourage the research on the chemo-diversity of French reef macroalgae for industrial applications as these organisms represent a reservoir of active ingredients that is still insufficiently explored.

The content of astaxanthin, including its mono- and diesters, and photosynthetic pigments, was studied in cells of H. pluvialis strain IBCE-H17 under combined prolonged action of several inducers of astaxanthin accumulation. The ineffectiveness of the simultaneous introduction of several inducers of astaxanthin accumulation in the culture medium during high-intensity light treatment was shown.

The environment of the sub-Antarctic ecoregion of Magallanes is highly heterogenous due to the influence of three oceans (Pacific, Atlantic, and Southern) and the effects of postglacial events such as the Last Glacial Maximum. In the sub-Antarctic ecoregion of Magallanes, the presence of two morphotypes of Durvillaea antarctica has recently been recorded that are related to the specific hydrodynamic configuration of the sites in the region. This study investigates the photosynthetic activity and pigment composition during two periods of the year in these two morphotypes of D. antarctica. One of them has broad and laminar fronds and occurs in wave-protected environments, while the other morphotype is characterized by cylindrical and elongated fronds and inhabits wave-exposed environments. The adult specimens of the “elongated-cylindrical” morphotype were collected in Seno Otway (53.1° S, 71.5° W) and the specimens of the “laminar” morphotype in Bahia el Aguila, San Isidro (53.7° S, 70.9° W). ETRmax, α, and Ek as parameters of the ETR-E curves were higher for the “laminar” than the “elongated-cylindrical” morphotype, resulting in significant values. The concentration of fucoxanthin was statistically higher for the morphotype “laminar” compared to the morphotype “elongated-cylindrical.” Both morphotypes exhibited different photosynthetic activities, perhaps attributed to their morphology, floatation capacity, and environment.

Fine earthenwares imported from England are a distinctive artifact type frequently found on early nineteenth century Native American and Euro-American sites in eastern North America. Relatively rapid changes in decorative motifs and technologies can easily be identified by eye and provide information about site chronology and economic status. However, visual analyses of sherds usually can provide only general information because most assemblages are very fragmented. We present the chemical composition of pigments and glazes from sherds from two sites occupied during the first half of the nineteenth century: Pokagon Village, a Native American site (southwestern Michigan); and Collier Lodge, a Euro-American site (northwestern Indiana). Multi-element compositions of glazed portions of 12 sherds (with 3 different decorations, 2 specimens from each site of each pattern) were determined by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), micro X-ray fluorescence (μXRF), and laser-ablation-inductively coupled mass spectrometry (LA-ICP-MS). SEM-EDS was especially useful for determining glaze composition, μXRF rapidly provides information on pigment composition and Pb content, and LA-MC-ICP-MS provides information on trace elements and Pb isotopes that reflect different raw material sources.

This study investigated photosynthetic pigments chlorophyll a and b, carotenoids (including xanthophyll cycle pigments) and antioxidants glutathione and tocopherols contents in chloro- (Lobaria pulmonaria, Lasallia pustulata) and cyanolichens (Lobaria scrobiculata, Peltigera canina) from different habitats and of different geographical origin. Lichen thalli were treated with various levels of irradiance (from 100 to 1500 mmol m-2 s-1) for various time periods (from 20 min. to 5 h). The extent of increase of zeaxanthin content after different light treatments differed among chlorolichens, clearly distinguishing the species from light and shade habitats. Irrespective of light treatment, β-carotene content was always higher in cyanobacterial species than in green algal species. Highest canthaxanthin concentration, as well as β-carotene concentration, was found in L. scrobiculata from shade habitat. The content of total glutathione was the same in the same species from different collection sites. On the contrary, contents of a-tocopherol differed in the same species from different collection sites.

Synechococcus sp. UTEX LB2380 is a coastal strain of a cosmopolitan cyanobacterial genus. In coastal waters, N and light availability are highly variable and their interplay may influence C allocation and photosynthetic performance. In this paper, we compared the impact of nitrogen (N) limitation and energy (light, E) limitation on phycobilisome composition and photosynthesis, in the presence of either NO3− or NH4+. Our hypothesis was that the phycobilisome composition would be influenced by the factor limiting growth. Our results show that N-limited cells adjusted their phycobilisome antenna to minimize N utilization, whereas E-limited cells had a phycobilisome composition tailored to alleviate E deficiency. The N-source was relevant for the pigment composition, under both limitations. When N limited growth, excess energy management may become important to decrease the risk of photoinhibition and oxidative stress; when the sink of electrons constituted by NO3− reduction was not present, the cells tended to decrease their phycobiliprotein content, possibly in order to minimize the size of PSII antennas and decrease excitation. When energy was limiting, the energy saved for N assimilation in NH4+-grown cells was invested in antenna pigments to allow for a higher energy input.

Chinese flame tree (Koelreuteria bipinnata var. integrifoliola), a common ornamental tree in southern China, exhibits a variety of fruit colors among individual plants within the same cultivated field. In this study, 44 plants with different fruit colors were selected to investigate the impact of pigment composition on the coloration of fruit peels. The plants were divided into three groups based on the color phenotype of the fruit peel: red, pink, and green. The values of lightness (L*) were negatively correlated with redness (a*) and positively correlated with yellowness (b*). The correlations of chroma (C*) with the other color parameters differed among the three groups. In the pooled pink and red groups, C* was negatively correlated with both L* and b* and positively correlated with a*, whereas the opposite relationships were found in the green group. According to the pigment analysis, anthocyanins, chlorophylls, and carotenoids were detected in the fruit peels. Anthocyanins were found to be the main pigment responsible for the differences in fruit color among the various groups. The highest anthocyanin content of fruit peel was found in the red group, followed by the pink group; the lowest anthocyanin levels appeared in the green group. The major anthocyanin component in the fruit peels was identified as cyanidin 3-O-rutinoside. By classifying fruit peel color and determining pigment composition, this study provides a theoretical basis for further researching genetic control and regulation of anthocyanin biosynthesis genes on pigment accumulation and peel coloration of chinese flame tree.

Freshwaters are increasingly exposed to artificial light at night (ALAN), yet the consequences for aquatic primary producers remain largely unknown. We used stream-side flumes to expose three-week-old periphyton to LED light. Pigment composition was used to infer community changes in LED-lit and control periphyton before and after three weeks of treatment. The proportion of diatoms/chrysophytes decreased (14%) and cyanobacteria increased (17%) in lit periphyton in spring. This may reduce periphyton nutritional quality in artificially-lit waters.

The yield of high-value products, such as pigments that could be extracted from microalgae, is affected by various nutritional and physical factors. Consequently, there is a need for fast visualization techniques that investigate the responses of individual microalgal cells to changing environmental conditions without introducing perturbations. Here, we apply CARS microscopy to map the distribution of pigments in the diatoms Ditylum brightwellii and Stephanopyxis turris and report their relative change in response to varying light cycles using a marker-based watershed analysis of the acquired images. Simultaneously, the underlying specific pigment composition alterations are revealed using Raman microspectroscopy at 785 nm excitation. In regards to assessing the chemical content of microalgae, these methods present themselves as viable alternatives to the standard techniques currently in use because of their non-disruptive nature and the wealth of complementary information that could be obtained from them.

To enrich the contents of digital archive and to guide the copy and restoration of colored relics, non-invasive methods for extraction of painting boundary and identification of pigment composition are proposed in this study based on the visible spectral images of colored relics. Superpixel concept is applied for the first time to the field of oversegmentation of visible spectral images and implemented on the visible spectral images of colored relics to extract their painting boundary. Since different pigments are characterized by their own spectrum and the same kind of pigment has the similar geometric profile in spectrum, an automatic identification method is established by comparing the proximity between the geometric profiles of the unknown spectrum from each superpixel and the pre-known spectrum from a deliberately prepared database. The methods are validated using the visible spectral images of the ancient wall paintings in Mogao Grottoes. By the way, the visible spectral images are captured by a multispectral imaging system consisting of two broadband filters and a RGB camera with high spatial resolution.