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Helicosporidium is a genus of nonphotosynthetic, green algae in the family Chlorellaceae, closely related to Prototheca. It is a known pathogen of invertebrates, and its occurrence in vertebrates has not been documented. A captive, 10-month-old, male, albino California kingsnake (Lampropeltis californiae) was submitted for necropsy. Gross examination revealed hemorrhagic laryngitis and a red mottled liver. Histologically, intravascular, intramonocytic/macrophagic and extracellular, eukaryotic organisms were observed in all tissues. These organisms stained positive with Grocott-Gomori methenamine silver and periodic acid-Schiff and were variably acid-fast and gram-positive. Ultrastructural analysis revealed approximately 4 µm vegetative multiplication forms and cysts with 3 parallel ovoid cells and a helically coiled filamentous cell. A polymerase chain reaction with primers targeting Prototheca, amplicon sequencing, and Bayesian phylogenetic analysis confirmed it clustered within Helicosporidium sp. with 100% posterior probability. The genus Helicosporidium was found to nest within the genus Prototheca, forming a clade with Prototheca wickerhamii with 80% posterior probability.

\nHighlightsTrebouxia microalgae have previously been mostly reported as lichen photobionts. However, in recent years, reports of their occurrence outside the lichen symbiosis has been more common. This study provides evidence of free-living Trebouxia species, as well as the re-evaluation of six strains from the Coimbra Collection of Algae (ACOI 1141, ACOI 1821, ACOI 2621, ACOI 2622, ACOI 2623 and ACOI 3426) obtained via micropipette single-cell isolation. The nuclear Internal Transcribed Spacer rDNA was sequenced to infer its phylogenetic position within Trebouxia genus. Strains ACOI 1141, ACOI 1821, ACOI 2621 and ACOI 3426 clustered in a large clade with a species-level lineage previously named as Trebouxia sp. A13. This lineage comprises sequences belonging to three previously described Trebouxia species: Trebouxia crenulata, Trebouxia arboricola and Trebouxia aggregata. Strain ACOI 2623 clustered with a species-level lineage not yet formally described, but previously detected and coded as Trebouxia sp. A19. ACOI 2622 separated into an independent clade distinct from all other sequences included in the dataset. This strain has not been previously identified as a species-level lineage in other studies, thus we code it as A60 and describe it as Trebouxia valentina sp. nov. based on morphological, ultrastructural, molecular and phylogenetic analyses. Our findings highlight the ability of these microalgae, typically associated with lichens, to thrive independently and expand our understanding of their biology and ecology. Free-living Trebouxia species were isolated and added to the ACOI.ACOI 2623 clustered with a species-level lineage not yet described.ACOI 2622 is here described as Trebouxia valentina sp. nov.Free-living Trebouxia species were isolated and added to the ACOI.ACOI 2623 clustered with a species-level lineage not yet described.ACOI 2622 is here described as Trebouxia valentina sp. nov. [ABSTRACT FROM AUTHOR]

Polar regions harbor a diversity of cold-adapted (cryophilic) algae, which can be categorized into psychrophilic (obligate cryophilic) and cryotrophic (nonobligate cryophilic) snow algae. Both can accumulate significant biomasses on glacier and snow habitats and play major roles in global climate dynamics. Despite their significance, genomic studies on these organisms remain scarce, hindering our understanding of their evolutionary history and adaptive mechanisms in the face of climate change. Here, we present the draft genome assembly and annotation of the psychrophilic snow algal strain CCCryo 101-99 (cf. Sphaerocystis sp.). The draft haploid genome assembly is 122.5 Mb in length and is represented by 664 contigs with an N50 of 0.86 Mb, a Benchmarking Universal Single-Copy Orthologs (BUSCO) completeness of 92.9% (n = 1,519), a maximum contig length of 5.3 Mb, and a guanine-cystosine (GC) content of 53.1%. In total, 28.98% of the genome (35.5 Mb) contains repetitive elements. We identified 417 noncoding RNAs and annotated the chloroplast genome. The predicted proteome comprises 14,805 genes with a BUSCO completeness of 97.8%. Our preliminary analyses reveal a genome with a higher repeat content compared with mesophilic chlorophyte relatives, alongside enrichment in gene families associated with photosynthesis and flagella functions. Our current data will facilitate future comparative studies, improving our understanding of the likely response of polar algae to a warming climate as well as their evolutionary trajectories in permanently cold environments. [ABSTRACT FROM AUTHOR]

Recently, scientists have shown interest in utilizing biochar made from natural sources to enhance various photovoltaic technologies. In this study, Zinc-Bis-8-hydroxyquinoline (Zn-Hq2) was mixed with 10 % biochar obtained from red sea microalgae (Chlorophyta) using a microwave combustion process. This mixture was then used as a novel photoactive layer in a solar cell. The structural properties of Zn-Hq2@BC were analyzed by XRD, FTIR, HRTEM, and SEM. The analysis showed that Zn-Hq2@BC had evenly distributed nano-rods within the BC nanopores network, with widths ranging from 26.94 to 30.90 nm and lengths ranging from 136.43 to 192.38 nm. When measuring dark current density-voltage, it was found that Zn-Hq2@BC/n-Si showed better-rectifying characteristics compared to pristine Zn-Hq2/n-Si, with a higher rectification ratio. The results also showed that the current density and voltage at the maximum power point increased to 5.63 mA/cm2 and 0.45 V, respectively, due to the activation of the biochar. When exposed to light, the addition of approximately 10 % biochar resulted in a 15 % increase in fill factor and a 92 % increase in power conversion efficiency. This is because biochar helps introduce extra charge carriers into the material, thus improving charge transport and reducing recombination losses. These findings reveal the positive effects of microalgae-derived biochar and indicate potential applications of Zn-Hq2 in solar cells.

In the evolution of eukaryotes, the transition from unicellular to simple multicellular organisms has happened multiple times. For the development of complex multicellularity, characterized by sophisticated body plans and division of labor between specialized cells, symplasmic intercellular communication is supposed to be indispensable. We review the diversity of symplasmic connectivity among the eukaryotes and distinguish between distinct types of non-plasmodesmatal connections, plasmodesmata-like structures, and 'canonical' plasmodesmata on the basis of developmental, structural, and functional criteria. Focusing on the occurrence of plasmodesmata (-like) structures in extant taxa of fungi, brown algae (Phaeophyceae), green algae (Chlorophyta), and streptophyte algae, we present a detailed critical update on the available literature which is adapted to the present classification of these taxa and may serve as a tool for future work. From the data, we conclude that, actually, development of complex multicellularity correlates with symplasmic connectivity in many algal taxa, but there might be alternative routes. Furthermore, we deduce a four-step process towards the evolution of canonical plasmodesmata and demonstrate similarity of plasmodesmata in streptophyte algae and land plants with respect to the occurrence of an ER component. Finally, we discuss the urgent need for functional investigations and molecular work on cell connections in algal organisms. [ABSTRACT FROM AUTHOR]

Recently, scientists have shown interest in utilizing biochar made from natural sources to enhance various photovoltaic technologies. In this study, Zinc-Bis-8-hydroxyquinoline (Zn-Hq2) was mixed with 10 % biochar obtained from red sea microalgae (Chlorophyta) using a microwave combustion process. This mixture was then used as a novel photoactive layer in a solar cell. The structural properties of Zn-Hq2@BC were analyzed by XRD, FTIR, HRTEM, and SEM. The analysis showed that Zn-Hq2@BC had evenly distributed nano-rods within the BC nanopores network, with widths ranging from 26.94 to 30.90 nm and lengths ranging from 136.43 to 192.38 nm. When measuring dark current density-voltage, it was found that Zn-Hq2@BC/n-Si showed better-rectifying characteristics compared to pristine Zn-Hq2/n-Si, with a higher rectification ratio. The results also showed that the current density and voltage at the maximum power point increased to 5.63 mA/cm2 and 0.45 V, respectively, due to the activation of the biochar. When exposed to light, the addition of approximately 10 % biochar resulted in a 15 % increase in fill factor and a 92 % increase in power conversion efficiency. This is because biochar helps introduce extra charge carriers into the material, thus improving charge transport and reducing recombination losses. These findings reveal the positive effects of microalgae-derived biochar and indicate potential applications of Zn-Hq2 in solar cells. [ABSTRACT FROM AUTHOR]

Simple Summary: The French Polynesian islands represent a unique insular system in the Pacific Ocean. Previous surveys of the marine flora of French Polynesia were mostly established on traditional morphology-based taxonomy. DNA barcoding allowed us to provide a major revision of French Polynesian marine flora, with an updated total of 702 species from French Polynesia, including 119 species of Chlorophyta, 169 Cyanobacteria, 92 Ochrophyta, 320 Rhodophyta, and 2 species of seagrasses (Alismatales)—nearly a two-fold increase from previous estimates. In addition to improving and refining our knowledge of French Polynesian marine flora, this study also provides a valuable DNA barcode reference library for identification purposes and future taxonomic and conservation studies. A significant part of the diversity uncovered corresponds to unidentified lineages, which will need careful taxonomic examination. Located in the heart of the South Pacific Ocean, the French Polynesian islands represent a remarkable setting for biological colonization and diversification, because of their isolation. Our knowledge of this region's biodiversity is nevertheless still incomplete for many groups of organisms. In the late 1990s and 2000s, a series of publications provided the first checklists of French Polynesian marine algae, including the Chlorophyta, Rhodophyta, Ochrophyta, and Cyanobacteria, established mostly on traditional morphology-based taxonomy. We initiated a project to systematically DNA barcode the marine flora of French Polynesia. Based on a large collection of ~2452 specimens, made between 2014 and 2023, across the five French Polynesian archipelagos, we re-assessed the marine floral species diversity (Alismatales, Cyanobacteria, Rhodophyta, Ochrophyta, Chlorophyta) using DNA barcoding in concert with morphology-based classification. We provide here a major revision of French Polynesian marine flora, with an updated listing of 702 species including 119 Chlorophyta, 169 Cyanobacteria, 92 Ochrophyta, 320 Rhodophyta, and 2 seagrass species—nearly a two-fold increase from previous estimates. This study significantly improves our knowledge of French Polynesian marine diversity and provides a valuable DNA barcode reference library for identification purposes and future taxonomic and conservation studies. A significant part of the diversity uncovered from French Polynesia corresponds to unidentified lineages, which will require careful future taxonomic investigation. [ABSTRACT FROM AUTHOR]

Recently, the isolation and identification of various biologically active secondary metabolites from algae have been of scientific interest, with particular attention paid to carotenoids, widely distributed in various photosynthetic organisms, including algal species. Carotenoids are among the most important natural pigments, with many health-promoting effects. Since the number of scientific studies on the presence and profile of carotenoids in algae has increased exponentially along with the interest in their potential commercial applications, this review aimed to provide an overview of the current knowledge (from 2015) on carotenoids detected in different algal species (12 microalgae, 21 green algae, 26 brown algae, and 43 red algae) to facilitate the comparison of the results of different studies. In addition to the presence, content, and identification of total and individual carotenoids in various algae, the method of their extraction and the main extraction parameters were also highlighted. [ABSTRACT FROM AUTHOR]

Simple Summary: The present review provides (1) an updated checklist of the Vietnamese marine flora, (2) a review of molecular-assisted alpha taxonomic efforts, (3) an analysis of marine floral biodiversity spatial distribution nationally and regionally (South China Sea), (4) a discussion on the impact of anthropogenic and environmental stressors on the Vietnamese marine flora, and (5) the efforts developed in the last decade for its conservation. The updated checklist consists of 878 species, including 439 Rhodophyta, 156 Ochrophyta, 196 Chlorophyta, 87 Cyanobacteria, and 15 seagrasses. The South Central Coast supports the highest species diversity of marine algae, which coincides with the largest density of coral reefs along the Vietnam coast. Vietnam holds one of the richest marine floras in the South China Sea owing to the country's coastline length and associated marine habitat diversity. However, the Vietnamese marine floral biodiversity is facing critical threats, and present management efforts are yet insufficient for their conservation. A methodical molecular-assisted re-examination of Vietnam marine floral biodiversity is urgently needed, complemented with in-depth investigations of the main threats targeted against it; and finally, conservation measures should be urgently implemented. Part of the Indo-Chinese peninsula and located on the northwest edge of the Coral Triangle in the South China Sea, the Vietnamese coastal zone is home to a wealthy marine biodiversity associated with the regional geological setting and history, which supports a large number of marine ecosystems along a subtropical to tropical gradient. The diversity of coastal benthic marine primary producers is also a key biological factor supporting marine biological diversity. The present review provides: (1) an updated checklist of the Vietnamese marine flora, (2) a review of molecular-assisted alpha taxonomic efforts, (3) an analysis of marine floral biodiversity spatial distribution nationally and regionally (South China Sea), (4) a review of the impact of anthropogenic and environmental stressors on the Vietnamese marine flora, and (5) the efforts developed in the last decade for its conservation. Based on the studies conducted since 2013 and the nomenclatural changes that occurred during this period, an updated checklist of benthic marine algae and seagrasses consisted in a new total of 878 species, including 439 Rhodophyta, 156 Ochrophyta, 196 Chlorophyta, 87 Cyanobacteria, and 15 phanerogam seagrasses. This update contains 54 new records and 5 new species of macroalgae. The fairly poor number of new records and new species identified in the last 10 years in a "mega-diverse" country can be largely attributed to the limited efforts in exploring algal biodiversity and the limited use of genetic tools, with only 25.4% (15 species) of these new records and species made based on molecular-assisted alpha taxonomy. The South Central Coast supports the highest species diversity of marine algae, which coincides with the largest density of coral reefs along the Vietnamese coast. Vietnam holds in the South China Sea one of the richest marine floras, imputable to the country's geographical, geological, and climatic settings. However, Vietnam marine floral biodiversity is under critical threats examined here, and current efforts are insufficient for its conservation. A methodical molecular-assisted re-examination of Vietnam marine floral biodiversity is urgently needed, complemented with in-depth investigations of the main threats targeting marine flora and vulnerable taxa, and finally, conservation measures should be urgently implemented. [ABSTRACT FROM AUTHOR]

One of the most important water bodies in Mexico is the Purisima Reservoir. It has been declared a protected natural area and provides ecosystem services. The aim of the present study was to assess the water quality and the degree of contamination in the reservoir using an integrated methodological approach to obtain a comprehensive knowledge of the environmental status of the reservoir. Physicochemical analyses, metal/metalloid determination and biomonitoring techniques were carried out. Algae were identified as the most feasible bioindicator. Data were processed using WAWQI, PAST 4.03, JMP15.2 and QGIs 3.26.3. The main elements identified in the reservoir were Cd, Cr, Hg, Pb and As (0.002–0.1 mg L−1). The element pairs with high correlation (p < 0.05) were Cd and Pb; Cr with Hg and Pb; Hg with Pb and Zn; and Pb and As. The taxonomic divisions of the algae observed were Bacillariophyta, Cyanobacteria, Charophyta and Chlorophyta. The results obtained classify the water quality of the Purisima Reservoir as "poor", while the biomonitoring analyses classify it as "moderately polluted". As a future perspective, a DNA meta-coding study of algal genera is recommended as it would increase the effectiveness of future biomonitoring programmes as well as the development of mapping techniques that correlate the degree of eutrophication with the population of bioindicators in order to design and implement effective protection and restoration policies. Finally, it should be noted that this is the first reported work on the study of the algae present in the Purisima Reservoir. [ABSTRACT FROM AUTHOR]

In the evolution of eukaryotes, the transition from unicellular to simple multicellular organisms has happened multiple times. For the development of complex multicellularity, characterized by sophisticated body plans and division of labor between specialized cells, symplasmic intercellular communication is supposed to be indispensable. We review the diversity of symplasmic connectivity among the eukaryotes and distinguish between distinct types of non-plasmodesmatal connections, plasmodesmata-like structures, and ‘canonical’ plasmodesmata on the basis of developmental, structural, and functional criteria. Focusing on the occurrence of plasmodesmata (-like) structures in extant taxa of fungi, brown algae (Phaeophyceae), green algae (Chlorophyta), and streptophyte algae, we present a detailed critical update on the available literature which is adapted to the present classification of these taxa and may serve as a tool for future work. From the data, we conclude that, actually, development of complex multicellularity correlates with symplasmic connectivity in many algal taxa, but there might be alternative routes. Furthermore, we deduce a four-step process towards the evolution of canonical plasmodesmata and demonstrate similarity of plasmodesmata in streptophyte algae and land plants with respect to the occurrence of an ER component. Finally, we discuss the urgent need for functional investigations and molecular work on cell connections in algal organisms.

Background: In recent years, Precambrian lifeforms have generated an ever-increasing interest because they revealed a rich eukaryotic diversity prior to the Cambrian explosion of modern animals. Among them, macroalgae are known to be a conspicuous component of Neoproterozoic ecosystems, and chlorophytes in particular are already documented in the Tonian, when they were so far expected to originate. However, like for other major eukaryotic lineages, and despite predictions of molecular clock analyses placing roots of these lineages well into the Neoproterozoic, a taxonomic constraint on Precambrian green algae has remained difficult. Results: Here, we present an exceptionally preserved spherical, coenocytic unicellular alga from the latest Ediacaran Dengying Formation of South China (> ca. 541 Ma), known from both external and internal morphology, fully tridimensional and in great detail. Tomographic X-ray and electronic microscopy revealed a characteristic medulla made of intertwined siphons and tightly packed peripheral utricles, suggesting these fossils belong to the Bryopsidales genus Codium. However, its distinctly smaller size compared to extant species leads us to create Protocodium sinense gen. et sp. nov. and a phylomorphospace investigation points to a possible stem group affinity. Conclusions: Our finding has several important implications. First, Protocodium allows for a more precise calibration of Archaeplastida and directly confirms that a group as derived as Ulvophyceae was already well diversified in various ecosystems prior to the Cambrian explosion. Details of tridimensional morphology also invite a reassessment of the identification of other Ediacaran algae, such as Chuaria, to better discriminate mono-versus multicellularity, and suggest unicellular Codium-like morphotypes could be much older and widespread. More broadly, Protocodium provides insights into the early diversification of the plant kingdom, the composition of Precambrian ecosystems, and the extreme longevity of certain eukaryotic plans of organization. [ABSTRACT FROM AUTHOR]

Premise: A novel control technique was developed to mitigate an invasive siphonous green alga, Avrainvillea lacerata (Dichotomosiphonaceae), within a shallow degraded reef flat in Oʻahu, Hawaiʻi. Methods and Results: Replicated treatments of 3% and 10% hydrogen peroxide (H2O2) were administered into individual basal attachments of the bed‐forming invasive seaweed on the Paikō reef, Oʻahu. Relative electron transport rate maxima (rETRm) were measured using a Walz Diving Pulse Amplitude Modulated Fluorometer in two replicate 100‐m2 plots in 2020. Over the period of this short‐term study, rETRm decreased following injections of either concentration of H2O2 in contrast with negative and positive controls. Conclusions: Compared with existing techniques that have used oxidizing agents in the marine environment in localized areas, the protocol described here has the potential to successfully decrease macroalgal carbon gain, potentially leading to loss of biomass at larger scales. [ABSTRACT FROM AUTHOR]

Premise of research. The Lower Devonian Rhynie chert preserves abundant microbial fossils that are similar morphologically to cyanobacteria and microscopic algae but cannot be placed systematically with confidence. Although often morphologically distinct, only a few of these fossils have been described. Methodology. Thin sections prepared from three different blocks of the Rhynie chert were examined at high magnification in transmitted light. Images of fossils were captured digitally and processed in Adobe Photoshop. Pivotal results. More than 150 specimens of Glaphyrobalantium hueberi gen. et sp. nov., a minute vesicle bounded by a prominent envelope and usually containing eight or more spherical bodies, were found. The fossils are similar to certain present-day coccoid cyanobacteria (e.g., Gloeocapsa ; Chroococcales) and algae (e.g., Gloeocystis ; Sphaeropleales) that occur in microscopic groups of two to eight (or more) cells surrounded by a colonial sheath and unicellular algae that reproduce asexually by autospores (e.g., Chlorococcum ; Chlamydomonadales), but affinities to protists, fungi, and fungus-like organisms can also not be ruled out. Conclusions. This discovery expands our knowledge of microbial life in the Rhynie paleoecosystem. Although the affinities remain elusive, it is important to describe fossils like G. hueberi as a first step toward understanding past microbial biodiversity and the roles microorganisms have had as constituents of ancient ecosystems. [ABSTRACT FROM AUTHOR]

Microalgae are diverse, with many gaps remaining in phylogenetic and physiological understanding. Thus, studying new microalgae species increases our broader comprehension of biological diversity, and evaluation of new candidates as algal production platforms can lead to improved productivity under a variety of cultivation conditions. Chlorella is a genus of fast‐growing species often isolated from freshwater habitats and cultivated as a source of nutritional supplements. However, the use of freshwater increases competition with other freshwater needs. We identified Chlorella desiccata to be worthy of further investigation as a potential algae production strain, due to its isolation from a marine environment and its promising growth and biochemical composition properties. Long‐read genomic sequencing was conducted for C. desiccata UTEX 2526, resulting in a high‐quality, near chromosome level, diploid genome with an assembly length of 21.55 Mbp in only 18 contigs. We also report complete circular mitochondrial and chloroplast genomes. Phylogenomic and phylogenetic analyses using nuclear, chloroplast, 18S rRNA, and actin sequences revealed that this species clades within strains currently identified as Nannochloris (Trebouxiophyceae, Chlorophyta), leading to its reclassification as Nannochloris sp. "desiccata" UTEX 2526. The mode of cell division for this species is autosporulation, differing from the type species N. bacillaris. As has occurred across multiple microalgae genera, there are repeated examples of Nannochloris species reclassification in the literature. This high‐quality genome assembly and phylogenetic analysis of the potential algal production strain Nannochloris sp. "desiccata" UTEX 2526 provides an important reference and useful tool for further studying this region of the phylogenetic tree. [ABSTRACT FROM AUTHOR]

Part of the Indo-Chinese peninsula and located on the northwest edge of the Coral Triangle in the South China Sea, the Vietnamese coastal zone is home to a wealthy marine biodiversity associated with the regional geological setting and history, which supports a large number of marine ecosystems along a subtropical to tropical gradient. The diversity of coastal benthic marine primary producers is also a key biological factor supporting marine biological diversity. The present review provides: (1) an updated checklist of the Vietnamese marine flora, (2) a review of molecular-assisted alpha taxonomic efforts, (3) an analysis of marine floral biodiversity spatial distribution nationally and regionally (South China Sea), (4) a review of the impact of anthropogenic and environmental stressors on the Vietnamese marine flora, and (5) the efforts developed in the last decade for its conservation. Based on the studies conducted since 2013 and the nomenclatural changes that occurred during this period, an updated checklist of benthic marine algae and seagrasses consisted in a new total of 878 species, including 439 Rhodophyta, 156 Ochrophyta, 196 Chlorophyta, 87 Cyanobacteria, and 15 phanerogam seagrasses. This update contains 54 new records and 5 new species of macroalgae. The fairly poor number of new records and new species identified in the last 10 years in a “mega-diverse” country can be largely attributed to the limited efforts in exploring algal biodiversity and the limited use of genetic tools, with only 25.4% (15 species) of these new records and species made based on molecular-assisted alpha taxonomy. The South Central Coast supports the highest species diversity of marine algae, which coincides with the largest density of coral reefs along the Vietnamese coast. Vietnam holds in the South China Sea one of the richest marine floras, imputable to the country’s geographical, geological, and climatic settings. However, Vietnam marine floral biodiversity is under critical threats examined here, and current efforts are insufficient for its conservation. A methodical molecular-assisted re-examination of Vietnam marine floral biodiversity is urgently needed, complemented with in-depth investigations of the main threats targeting marine flora and vulnerable taxa, and finally, conservation measures should be urgently implemented.

The paper deals with the macrophytic algae in Astara region of Azerbaijan. Samples were collected in 2021 from the Caspian coast of Astara region. As a result of the study, 9 species (Cladophora vagabunda, Cladophora prolifera, Cladophora laetevirens, Cladophora globulina, Cladophora sericea, Ulva clathrata, Erythrorichia bertholdii, Ceramium elegans, Kylinia virgatula) of 5 genera were identified. These species are new for this region. GPS coordinates (38°27'10.05"K; 48°52'50.23"D) and ecological groups of algae have been determined. [ABSTRACT FROM AUTHOR]

Since the nineteenth century, a ring-forming disease attacking Antarctic mosses has been reported. However, to date, only the effects on the mosses themselves are known. In this study, we used DNA metabarcoding to investigate the effects on the moss epiphytic algal community at different stages of disease progression. As the disease progressed, algal species richness decreased, although overall abundance was not significantly affected. Prasiolales appeared unaffected, whereas Ulotrichales were more sensitive. Trebouxiales dominated the advanced disease stage, suggesting a possible benefit from the disease, either through the elimination of competition or creation of new niches. Infection is responsible for moss death, leading to habitat loss for other organisms, but pathogenic effects on algae cannot be ruled out. Our data indicate that the disease not only impacts mosses but also other groups, potentially resulting in loss of Antarctic biodiversity. This study provides the first report of the disease effects on epiphytic algal communities of Antarctic bryophytes. [ABSTRACT FROM AUTHOR]

Volvox barberi is a multicellular green alga forming spherical colonies of 10,000–50,000 differentiated somatic and germ cells. We observed that in culture, these colonies actively self‐organized in just a few minutes into "flocks" that contained as many as 100 colonies moving and rotating collectively for hours. The colonies in flocks formed two‐dimensional, irregular, active crystals, that is, geometric lattices within which individual colonies rotated separately. These groupings sometimes disassembled back into individual colonies just as quickly, but in some cases, flocks persisted over several hours. Close inspection of flock formation in the presence of a tracer dye suggested that colony and flock rotations were producing vortices in the fluid medium over a range spanning multiple flock diameters, perhaps providing a physical mechanism for aggregation. [ABSTRACT FROM AUTHOR]

Chlamydomonas proboscigera is a unicellular, ellipsoidal-to-spherical chlorophyte distinguished by a flattened papilla, a large spherical pyrenoid and a disc-shaped stigma located anterior in a cup-shaped chloroplast. The species is common in eutrophic water, but also occurs in terrestrial environments, such as soils. Previously, Chlamydomonas proboscigera was only described from certain parts of Europe, Asia and northern Africa (Algeria). The findings of C. proboscigera in South Africa during 2019, represent the first reported record of this species in the southern hemisphere and sub-Saharan Africa. [ABSTRACT FROM AUTHOR]

The importance of herbivores and of plant diversity for community succession and recovery from disturbance is well documented. However, few studies have assessed the relative magnitude of, or potential interactions between, these factors. To determine the combined effect of herbivory and surrounding algal species richness on the recovery of a rocky intertidal community, we conducted a 27-month field experiment assessing algal recruitment and succession in cleared patches that mimic naturally forming gaps in the ambient community. We crossed two herbivore treatments, ambient and reduced abundance, with monocultures and polycultures of the four most common algal species in a mid-high rocky intertidal zone of northern California. We found that both the presence of herbivores and high surrounding algal richness increased recovery rates, and the effect of algal richness was twice the magnitude of that of herbivores. The increased recovery rate of patches containing herbivores was due to the consumption of fast-growing, early colonist species that preempt space from perennial, late-successional species. Mechanisms linking algal richness and recovery are more numerous. In polycultures, herbivore abundance and species composition is altered, desiccation rates are lower, and propagule recruitment, survival, and growth are higher compared to monocultures, all of which could contribute the observed effect of surrounding species richness. Herbivory and species richness should jointly accelerate recovery wherever palatable species inhibit late-successional, herbivore-resistant species and recruitment and survival of new colonists is promoted by local species richness. These appear to be common features of rocky-shore seaweed, and perhaps other, communities.

Abstract We present here the first confirmed record of the genus Gloeotaenium in Brazil. The representative species (Gloeotaenium loitlesbergianum) was collected in a stream from Curaçá, northern Bahia state, Brazil. We provide a description of the species, illustrations, and taxonomic notes.

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Growing algae in darkness for biodiesel production eliminates the challenges of evaporation and light penetration reported for open ponds and the costs and fouling that plague photobioreactors. The current study demonstrated that Chlorella kessleri str. UTEX 263 could grow heterotrophically in the dark on pure sugars or lignocellulosic hydrolysates of plant biomass. Hydrolysates of a prairie grass native to Kansas, Big Bluestem (Andropogon gerardii), supported the growth of C. kessleri in the dark. Nitrogen limitation stimulated the accumulation of biodiesel lipids by 10-fold in heterotrophic cultures grown on pure sugars or Big Bluestem hydrolysate. Limiting P in the growth medium also was shown to increase cellular lipid accumulation in C. kessleri. Iron limitation was not sufficient to increase cellular lipid content. Crude biomass extracts may have levels of N that cannot be easily removed, which are high enough to relieve N limitations in growth media. This initial study suggests that P might be more easily removed from biomass extracts than N for increasing cellular lipid production by nutrient limitation and further that native prairie grasses are potentially suitable as sources of lignocellulosic sugars. [ABSTRACT FROM AUTHOR]

This review article explores the state of DNA barcoding of macroalgae in the Mediterranean Sea. Data from the Barcode of Life Data System (BOLD) were utilised in conjunction with a thorough bibliographic review. Our findings indicate that from around 1124 records of algae in the Mediterranean Sea, only 114 species have been barcoded. We thus conclude that there are insufficient macroalgal genetic data from the Mediterranean and that this area would greatly benefit from studies involving DNA barcoding. Such research would contribute to resolving numerous questions about macroalgal systematics in the area and address queries related to biogeography, especially those concerned with non-indigenous species. It could also possibly result in the development and application of better, cost-effective biodiversity monitoring programmes emanating from UN conventions and EU Directives. One possible way of achieving this is to construct DNA libraries via sequencing and barcoding, subsequently enabling better cost-effective biodiversity monitoring through environmental DNA metabarcoding. [ABSTRACT FROM AUTHOR]

Several strains of terrestrial algae isolated from biological soil crusts in Germany and Ukraine were identified by morphological methods as the widely distributed species Dictyosphaerium minutum (=Dictyosphaerium chlorelloides). Investigation of the phylogeny showed their position unexpectedly outside of Chlorellaceae (Trebouxiophyceae) and distantly from Chlorella chlorelloides, to which this taxon was attributed after revision of the genus Chlorella based on an integrative approach. SSU rRNA phylogeny determined the position of our strains inside a clade recently described as a new genus of the cryptic alga Xerochlorella olmiae isolated from desert biological soil crusts in the United States. Investigation of the morphology of the authentic strain of X. olmiae showed Dictyosphaerium‐like morphology, as well as some other characters, common for our strains and morphospecies D. minutum. The latter alga was described as terrestrial and subsequently united with the earlier described aquatic representative D. chlorelloides because of their similar morphology. The revision of Chlorella mentioned above provided only one aquatic strain (D. chlorelloides), which determined its position in the genus. But terrestrial strains of the morphospecies were not investigated phylogenetically. Our study showed that the terrestrial D. minutum is not related to the morphologically similar D. chlorelloides (=Chlorella chlorelloides, Chlorellaceae), and instead represented a separate lineage in the Trebouxiophyceae, recently described as genus Xerochlorella. Therefore, revision of Xerochlorella is proposed, including nomenclatural combinations, epitypifications, and emendations of two species: X. minuta and X. dichotoma. New characters of the genus based on investigation of morphology and ultrastructure were determined. [ABSTRACT FROM AUTHOR]

Terrestrial diatoms are an integral component of the soil microbial community. However, their productivity and how it compares to other algal groups remains poorly known. This lack of knowledge hampers their potential use as environmental markers in various applications. As a way forward, we investigated the seasonal and spatial patterns of diatom assemblages and the role of environmental factors on the soil diatom productivity. We collected soil algal samples in 16 sites across the Attert River basin (Luxembourg) every 4 weeks for a period of 12 months. The algal abundances were then derived from pigment analysis using High-Performance Liquid Chromatography. Our results indicate that diatom productivity is mainly controlled by factors related to soil moisture availability leading to seasonal patterns, whereas the concentration of green algae remained stable over the course of the study period. Generally, anthropic disturbed habitats contained less living diatom cells than undisturbed habitats. Also, we learned that diatoms can be the dominant algal group at periods of the year with high soil moisture. [ABSTRACT FROM AUTHOR]

Several strains of terrestrial algae isolated from biological soil crusts in Germany and Ukraine were identified by morphological methods as the widely distributed species Dictyosphaerium minutum (=Dictyosphaerium chlorelloides). Investigation of the phylogeny showed their position unexpectedly outside of Chlorellaceae (Trebouxiophyceae) and distantly from Chlorella chlorelloides, to which this taxon was attributed after revision of the genus Chlorella based on an integrative approach. SSU rRNA phylogeny determined the position of our strains inside a clade recently described as a new genus of the cryptic alga Xerochlorella olmiae isolated from desert biological soil crusts in the United States. Investigation of the morphology of the authentic strain of X. olmiae showed Dictyosphaerium‐like morphology, as well as some other characters, common for our strains and morphospecies D. minutum. The latter alga was described as terrestrial and subsequently united with the earlier described aquatic representative D. chlorelloides because of their similar morphology. The revision of Chlorella mentioned above provided only one aquatic strain (D. chlorelloides), which determined its position in the genus. But terrestrial strains of the morphospecies were not investigated phylogenetically. Our study showed that the terrestrial D. minutum is not related to the morphologically similar D. chlorelloides (=Chlorella chlorelloides, Chlorellaceae), and instead represented a separate lineage in the Trebouxiophyceae, recently described as genus Xerochlorella. Therefore, revision of Xerochlorella is proposed, including nomenclatural combinations, epitypifications, and emendations of two species: X. minuta and X. dichotoma. New characters of the genus based on investigation of morphology and ultrastructure were determined. [ABSTRACT FROM AUTHOR]

Voronocladus dryganti Skompski et al. was recently erected as a new genus and species of dasycladalean alga on the basis of material from the Ludlovian Konivka Formation of western Ukraine. The thalli of this noncalcified macroalga are remarkable not only for their exceptional preservation, but also for showing unusual structures at the top, which were interpreted as epibionts. Here, an alternative interpretation is proposed for this material. In it, the affinity of Voronocladus as a siphonous green macroalga is retained, but as a bryopsidalean rather than dasycladalean alga, and the graptolite-like structures at the top are considered to represent the uppermost siphons of mature thalli instead of epibionts. Detailed morphological comparisons with living bryopsidalean taxa, as well as taphonomic and evolutionary considerations and key basal divergence dates indicated by molecular clock studies, provide support for the new interpretation. Viewed in broader terms, the reinterpreted morphology of Voronocladus is important because it (1) provides novel insights regarding the phylogenetic affinity of Ordovician and Silurian macroalgae with a form broadly similar to Voronocladus , and (2) helps to resolve the outlines of a major radiation of bryopsidalean algae that began during the Ordovician and continued into the Silurian. This event, which is only now beginning to come into focus, includes the initial evolution of Caulerpa - and Codium -like thalli and coincides with a major radiation of dasycladalean algae. • Voronocladus is transferred from Dasycladales to Bryopsidales within the Chlorophyta. • Voronocladus resembles living Bryopsidales with a stalked-blade thallus architecture. • Podoliagraptus algaeoides is established as a junior synonym of Voronocladus dryganti. • Chaetocladus is reevaluated in light of the new interpretation of Voronocladus. • Voronocladus originated as part of a major early Paleozoic radiation of Bryopsidales. [ABSTRACT FROM AUTHOR]

Cultivation of the filamentous chlorophyte Oedogonium in municipal wastewater effluent is known to improve water quality and yield lipid- and protein-rich biomass for industrial applications. Chlorophyte celluloses, whose molecular organization and physical traits differ from those of plants, represent yet another valuable extractive, and algal oxygen production is of economic value in wastewater treatment. Consequently, we explored cellulose and oxygen production from Oedogonium biomass batch-cultivated in treated secondary municipal wastewater effluent. We compared biomass, cellulose, and oxygen production outside and within an adjacent greenhouse, under differing dissolved CO2 and pH conditions, and during temperate-zone seasonal change from summer through fall. Overall production did not differ within or outside the greenhouse, but outside production was higher in summer and lower in fall as air temperatures declined. Batch cultivation offered advantages, but high levels of mixing and CO2 were essential to maintain neutral pH for optimal algal growth and oxygen production. [ABSTRACT FROM AUTHOR]

The biotechnology in Latin America has had a substantial increase in scientific productions occupying 4.96% of the world production, being Brazil and México the countries that generate the highest production. Since 2004, the Latin American Congress of Algal Biotechnology (CLABA) has been held, bringing together different specialized branches in both micro and macro algae. The aim of this work is to get an approximation on the trends in algal biotechnology in Latin America using as data the researches presented in the VI CLABA carried out in October 2017 in Lima (Peru). The information was organized in a matrix where the species used were identified; likewise, it was classified according to the phylum and the groups of eukaryotes/bacteria. In the same way, the investigations were classified according to their application. Chlorophyta (47%), Cyanobacteria (16%) and Ochrophyta (13%) were among the most relevant groups in terms of phylum; on the other hand, the most outstanding group of eukaryote/bacteria were Archaeplastida (57%), Stramenopiles (24%) and Cyanobacteria (17%). It is interesting that, in spite of being a congress of algae, 16% of organisms used were cyanobacteria, probably due to the taxonomic tradition in this group of polyphyletic organisms. The most used applications in this congress are oriented to aquaculture and care of the environment. [ABSTRACT FROM AUTHOR]

Growth, photosynthetic parameters, and biochemical composition of the chlorophyte Micractinium inermum were determined under conditions of different light-emitting diode (LED) wavelength distributions and carbon dioxide (CO2) levels of 1, 5, and 10% v/v. Increasing the inflowing CO2 concentration from 1 to 5 to 10% had negative effects on maximum growth rate (μmax), relative growth rate (RGR), biomass production, and CO2 fixation rate. Cultures subjected to a spectral distribution containing a blue wavelength peak were less negatively affected than red as CO2 stress increased, and evidently there was a quantitative effect depending on the peak area percentage. Under non-stressful conditions (1% CO2), there were no significant differences in μmax or RGR among light treatments; however, blue light resulted in decreased lag phases (0.75 less days than red). Biomass production was significantly higher in red wavelength peak treatments at 1% CO2 (i.e., monochromatic red treatment = 0.772 ± 0.07 g L−1) which demonstrates that although blue light allows for an early growth advantage, cultures grown with red light are able to catch up and result in more biomass. At a 10% CO2 level, RGR was higher in treatments with blue peaks; red peak treatments were no longer able to overcome the stress and demonstrated lag phases 4.87 days longer than blue peak treatments. Inhibition of photosystem II function was evident as CO2 concentrations increased. Evaluation of biochemical composition revealed that protein content was significantly greater in blue peak treatments at 10% CO2, pigment content was up to 2× greater than red at all CO2 levels, and total FAME and fatty acid profiles did not exhibit major changes. [ABSTRACT FROM AUTHOR]

The macromolecular composition of macroalgae influences nutrient flow and food quality in aquatic ecosystems and the value of macroalgae species for human consumption, aquaculture, biofuels, and other applications. We used literature data (125 publications, 1,117 observations) and a hierarchal Bayesian statistical model to estimate the average macromolecular composition, protein, lipid, and carbohydrate of macroalgae as a whole and at the phylum level. Our focus was on marine, noncalcified macroalgae sampled from wild‐grown populations in the field. We found that the median macromolecular composition is 9.98% protein, 2.7% lipid, 48.5% carbohydrate, and 31.8% ash as percent dry weight. We compared the median macromolecular content of macroalgae to microalgae and herbaceous plants and test for differences in macromolecular content across macroalgal phyla. Macroalgae were much more enriched in carbohydrate and minerals than the microalgae and lower in protein and lipid than many herbaceous plants. Rhodophyte macroalgae have significantly less lipid and more protein and the Ochrophyte macroalgae have significantly less protein than the average. [ABSTRACT FROM AUTHOR]

Molecular characterization based on the internal transcribed spacer 2 (ITS2) sequence identified Micractinium inermum JL1, a local isolate of green alga capable of growing robustly under photoautotrophic, mixotrophic, and heterotrophic culture modes. Physiochemical analyses of the alga revealed great variations in growth, lipid content, oleic acid abundance, and productivities of lipids and triacylglycerol (TAG) under various culture conditions including nitrogen concentrations, phosphorus concentrations, light intensities, salinity levels, and glucose concentrations with or without light illumination. The carbon shunt from starch and to a lesser extent from membrane lipids likely contributed to the TAG accumulation. Noteworthily, salt supplementation promoted TAG content and productivity by ~ 88% and ~ 55%, respectively. The alga could accumulate ~ 52% lipids per dry weight and achieved a high lipid productivity of 0.68 g L−1 day−1. C18:1 percentage, a biodiesel quality indicator, reached ~ 50%, and correlated well with TAG contents in a positive manner, demonstrating the feasibility of using C18:1 percentage for TAG quantification thereby avoiding time- and labor-intensive analysis. These results together indicate the potential of M. inermum JL1 as a lipid producer for future exploration. [ABSTRACT FROM AUTHOR]

Background: Botryococcus braunii is well known from all continents, but it has been sparsely recorded from Africa compared to other continents. The alga recently formed a rusty orange-red bloom in the Tilda Viljoen Dam, situated near Gobabis in Namibia. Blooms of this species are known to produce allelopathic substances that inhibit the growth and diversity of other phytoplankton, zooplankton and fish. Objectives: The objective of this study was to record the presence of B. braunii in Namibia. Method: Morphological features of the species were compared with illustrations and literature on B. braunii found in other continents of the world, particularly North America and Europe. Extensive literature surveys revealed its currently known geographical distribution. Results: The organism responsible for the discolouration of the water was identified as B. braunii. Microscopic examination revealed large colonies that floated in a thick layer on the surface of the water. Literature searches on the geographical distribution of B. braunii revealed that this was the first record of this species’ presence in Namibia. Conclusion: The known geographical distribution of B. braunii was expanded to include Namibia.

In the present study, monthly and seasonal variations in abundance of green seaweeds from the coastal region of Undi, Ratnagiri district along the west coast of Maharashtra were investigated. Stratified random sampling was carried out during monthly lowest tides along the exposed intertidal rocky shore area. For the estimation of percentage coverage of seaweeds, photo-quadrate method was employed and for the quantitative estimation of green seaweeds, collected samples from the quadrate were sorted out separately as per species and wet/ fresh weights were taken for density and biomass estimation of respective seaweed species. A total of ten green seaweeds were found in the rocky shore of Undi, namely, Bryopsis plumosa, Chaetomorpha antennina, Chaetomorpha crassa, Caulerpa racemosa, Caulerpa peltata, Caulerpa taxifolia, Caulerpa sertularioides, Ulva lactuca, Ulva fasciata and Valonia utricularis. In the study area, most of the green seaweeds were recorded with maximum abundance during pre-monsoon and post-monsoon seasons, while in monsoon season, the abundance of most of the green seaweeds declined remarkably. Unlike other seaweeds, maximum biomass of seaweeds, Bryopsis plumosa and Ulva lactuca was recorded during monsoon season. Among the green seaweeds, species like Caulerpa peltata, Ulva lactuca and Caulerpa taxifolia were recorded throughout the year. During whole monsoon season, among green seaweeds, Ulva fasciata was totally absent while during late pre-monsoon, species like Bryopsis plumosa, Chaetomorpha crassa, Caulerpa racemosa and Valonia utricularis were totally absent. The maximum biomass of Caulerpa peltata was recorded in the month of February 2018 in pre-monsoon period. The water pH showed highly significant positive correlation with abundance of green seaweeds, Caulerpa peltata and Ulva fasciata. Green seaweeds were found to be abundant along the coastal margin of Ratnagiri, with species specific seasonal variations in their abundance. [ABSTRACT FROM AUTHOR]

Chlorella species are known to be potential algal candidates for biodiesel production due to their ability to store lipids and their natural metabolic versatility. This study assessed the photosynthetic performance, biochemical composition, and metabolomic profiles of tropical Chlorella UMACC050 harvested from different growth phases in batch culture, grown under nitrogen-replete, and nitrogen-depleted conditions. Physiological data suggested that growth and photosynthetic efficiency were affected during nitrogen deprivation. Nitrogen deprivation resulted in a decrease in biomass productivity and an increase of lipid content. Nitrogen-depletion resulted in an increase in saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA), especially C16:0, C18:0, and C18:1, at the expense of polyunsaturated fatty acids (PUFA). Changes in the metabolomic profiles suggested that there was nitrogen assimilation from proteins and photosynthetic machinery, together with repartitioning of carbon into carbohydrates and lipids in response to nitrogen depletion. Overall, our results expand the current understanding of metabolomics of Chlorella species and provide valuable insights into their lipid accumulation during nitrogen deprivation, which is important for optimization of lipid productivity in the tropical environment. [ABSTRACT FROM AUTHOR]

This study was carried out to study species of marine green algae (Chlorophya) collected from six stations along, Iraqi coast in the north-west of Arabian Gulf, at different depths and seasons during the year 2013. Eighteen species of Chlorophyta were recorded during this work, twelve of them were recorded for the first time in Iraqi marine coastal water. Four species (Codium tomentosum, Monostroma grevillea, Prasiola calophylla, and Prasiola stipitata) are new for Arabian Gulf region. [ABSTRACT FROM AUTHOR]

The Chaetophorales (Chlorophyceae) consist of filamentous green algae that were mostly described directly from natural samples by light microscopy. However, the descriptions were often based on morphological characters that are either homoplasious or sensitive to environmental factors. This clearly prevents proper identification of several chaetophoralean taxa and highlights the need for taxonomic revision at different taxonomic levels. In the present study, we focused on revision of the Chaetophorales at the family level. We used a well-resolved molecular phylogeny to re-evaluate morphological characters in the Chaetophorales under clearly defined laboratory conditions. We identified five morphological characters that permitted unambiguous identification of most chaetophoralean families, and used these characters to establish a new family, the Fritschiellaceae (fam. nov.), and emend the Chaetophoraceae Greville 1824. Knowledge gained from this study lends additional weight to the current classification of the Chaetophorales and may serve as an example for taxonomic revisions of other complex filamentous algae. [ABSTRACT FROM AUTHOR]

Macroalgae are a rich source of biologically active chemical diversity for pharmaceutical and agrichemical discovery. However, the ability to understand the complexities of their chemical diversity will dictate whether these natural products have a place in modern discovery paradigms. In this study, we examined the relationship between secondary metabolite production and biological activity for a cohort of 127 macroalgae samples collected from various locations across South Eastern Australia. Approximately 20% of the macroalgae samples showed high levels of chemical diversity and productivity, which also correlated strongly with bioactivity. These “talented” species represent sustainable sources of metabolites that may be readily harvested for large-scale production. At a taxonomic level, significant differences in metabolite production and diversity were observed between Chlorophyta, Rhodophyta and Phaeophyta. For each talented species, the cometabolite pattern was unique to that species, with closely related species within the same genus displaying very different profiles. Despite over 50 years of investigation, we estimate that more than two-thirds of the chemical diversity of macroalgae remains unknown to science. By understanding the physicochemical properties and distribution patterns of metabolites, it is possible to make reasoned judgements about sustainable sourcing of macroalgae for biodiscovery. [ABSTRACT FROM AUTHOR]

Premise of the Study: Phylogenomic analyses across the green algae are resolving relationships at the class, order, and family levels and highlighting dynamic patterns of evolution in organellar genomes. Here we present a within‐family phylogenomic study to resolve genera and species relationships in the family Hydrodictyaceae (Chlorophyceae), for which poor resolution in previous phylogenetic studies, along with divergent morphological traits, have precluded taxonomic revisions. Methods: Complete plastome sequences and mitochondrial protein‐coding gene sequences were acquired from representatives of the Hydrodictyaceae using next‐generation sequencing methods. Plastomes were characterized, and gene order and content were compared with plastomes spanning the Sphaeropleales. Single‐gene and concatenated‐gene phylogenetic analyses of plastid and mitochondrial genes were performed. Key Results: The Hydrodictyaceae contain the largest sphaeroplealean plastomes thus far fully sequenced. Conservation of plastome gene order within Hydrodictyaceae is striking compared with more dynamic patterns revealed across Sphaeropleales. Phylogenetic analyses resolve Hydrodictyon sister to a monophyletic Pediastrum, though the morphologically distinct P. angulosum and P. duplex continue to be polyphyletic. Analyses of plastid data supported the neochloridacean genus Chlorotetraëdron as sister to Hydrodictyaceae, while conflicting signal was found in the mitochondrial data. Conclusions: A phylogenomic approach resolved within‐family relationships not obtainable with previous phylogenetic analyses. Denser taxon sampling across Sphaeropleales is necessary to capture patterns in plastome evolution, and further taxa and studies are needed to fully resolve the sister lineage to Hydrodictyaceae and polyphyly of Pediastrum angulosum and P. duplex. [ABSTRACT FROM AUTHOR]