scholarly journals A microbial eukaryote with a unique combination of purple bacteria and green algae as endosymbionts

2021 ◽  
Vol 7 (24) ◽  
pp. eabg4102
Author(s):  
Sergio A. Muñoz-Gómez ◽  
Martin Kreutz ◽  
Sebastian Hess
Keyword(s):  
Energy Metabolism ◽  
Green Algae ◽  
Purple Bacteria ◽  
Ecological Niches ◽  
Unique Combination ◽  
Anoxygenic Photosynthesis ◽  
Microbial Eukaryote ◽  
Eukaryotic Algae ◽  
Candidate Species ◽  
Partial Overlap

Oxygenic photosynthesizers (cyanobacteria and eukaryotic algae) have repeatedly become endosymbionts throughout evolution. In contrast, anoxygenic photosynthesizers (e.g., purple bacteria) are exceedingly rare as intracellular symbionts. Here, we report on the morphology, ultrastructure, lifestyle, and metagenome of the only “purple-green” eukaryote known. The ciliate Pseudoblepharisma tenue harbors green algae and hundreds of genetically reduced purple bacteria. The latter represent a new candidate species of the Chromatiaceae that lost known genes for sulfur dissimilation. The tripartite consortium is physiologically complex because of the versatile energy metabolism of each partner but appears to be ecologically specialized as it prefers hypoxic sediments. The emergent niche of this complex symbiosis is predicted to be a partial overlap of each partners’ niches and may be largely defined by anoxygenic photosynthesis and possibly phagotrophy. This purple-green ciliate thus represents an extraordinary example of how symbiosis merges disparate physiologies and allows emergent consortia to create novel ecological niches.

scholarly journals Dual bloom of green algae and purple bacteria in an extremely shallow soda pan

Extremophiles ◽  
2019 ◽  
Vol 23 (4) ◽  
pp. 467-477 ◽  
Author(s):  
Kristóf Korponai ◽  
Attila Szabó ◽  
Boglárka Somogyi ◽  
Emil Boros ◽  
Andrea K. Borsodi ◽  
...  
Keyword(s):  
Green Algae ◽  
Purple Bacteria ◽  
Soda Pan

Accessory pigment fluorescence for quantitation of photosynthetic microbial populations

1977 ◽  
Vol 23 (11) ◽  
pp. 1594-1597 ◽  
Author(s):  
Douglas E. Caldwell
Keyword(s):  
Linear Function ◽  
Green Algae ◽  
Cell Concentration ◽  
Purple Bacteria ◽  
Microbial Populations ◽  
Green Bacteria ◽  
In Vivo Fluorescence ◽  
Accessory Pigment ◽  
Cell Concentrations

The in vivo fluorescence of the primary accessory pigments in purple bacteria (carotenoids), green bacteria (bacteriochlorophyll), green algae (chlorophyll), and cyanobacteria (phycocyanin) was found to be a linear function of cell concentration over three to four orders of magnitude. The lowest cell concentrations detectable were 104 cells/ml for procaryotes and 103 cells/ml for eucaryotes.

scholarly journals Differential Cetacea Circadian Rhythmicity is associated with the molecular erosion of Cortistatin

2020 ◽  
Author(s):  
Raul Valente ◽  
Luís Q. Alves ◽  
Matilde Nabais ◽  
Filipe Alves ◽  
Isabel Sousa-Pinto ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Slow Wave Sleep ◽  
Circadian Rhythmicity ◽  
Ecological Niches ◽  
Deleterious Mutations ◽  
Thermal Constraints ◽  
Physiological Alterations ◽  
Pleiotropic Action ◽  
Mammalian Genomes ◽  
Molecular Landscape

AbstractThe ancestors of Cetacea underwent profound morpho-physiological alterations. By displaying an exclusive aquatic existence, cetaceans evolved unique patterns of locomotor activity, vigilant behaviour, thermoregulation and circadian rhythmicity. Deciphering the molecular landscape governing many of these adaptations is key to understand the evolution of phenotypes. Here, we investigate Cortistatin (CORT), a neuropeptide displaying an important role mammalian biorhythm regulation. This neuropeptide is a known neuroendocrine factor, stimulating slow-wave sleep, but also involved in the regulation of energy metabolism and hypomotility inducement. We assessed the functional status of CORT in 139 mammalian genomes (25 orders), including 30 species of Cetacea. Our findings indicate that cetaceans and other mammals with atypical biorhythms, thermal constraints and/or energy metabolism, have accumulated deleterious mutations in CORT. In light of the pleiotropic action of this neuropeptide, we suggest that this inactivation contributed to a plethora of phenotypic adjustments to accommodate adaptive solutions to specific ecological niches.

scholarly journals Exciton Origin of Color-Tuning in Ca2+-Binding Photosynthetic Bacteria

2021 ◽  
Vol 22 (14) ◽  
pp. 7338
Author(s):  
Kõu Timpmann ◽  
Margus Rätsep ◽  
Liina Kangur ◽  
Alexandra Lehtmets ◽  
Zheng-Yu Wang-Otomo ◽  
...  
Keyword(s):  
Photosynthetic Bacteria ◽  
Purple Bacteria ◽  
Red Light ◽  
Ecological Niches ◽  
Spectroscopic Techniques ◽  
Color Adaptation ◽  
Photosynthetic Organisms ◽  
Infra Red ◽  
Pigment Protein Complex ◽  
Physical Principles

Flexible color adaptation to available ecological niches is vital for the photosynthetic organisms to thrive. Hence, most purple bacteria living in the shade of green plants and algae apply bacteriochlorophyll a pigments to harvest near infra-red light around 850–875 nm. Exceptions are some Ca2+-containing species fit to utilize much redder quanta. The physical basis of such anomalous absorbance shift equivalent to ~5.5 kT at ambient temperature remains unsettled so far. Here, by applying several sophisticated spectroscopic techniques, we show that the Ca2+ ions bound to the structure of LH1 core light-harvesting pigment–protein complex significantly increase the couplings between the bacteriochlorophyll pigments. We thus establish the Ca-facilitated enhancement of exciton couplings as the main mechanism of the record spectral red-shift. The changes in specific interactions such as pigment–protein hydrogen bonding, although present, turned out to be secondary in this regard. Apart from solving the two-decade-old conundrum, these results complement the list of physical principles applicable for efficient spectral tuning of photo-sensitive molecular nano-systems, native or synthetic.

scholarly journals Disentangling the Impacts of Speciation, Sympatry and the Island Effect on the Morphology of Seven Hynobius sp. Salamanders

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 187
Author(s):  
Amaël Borzée ◽  
Mi-Sook Min
Keyword(s):  
Korean Peninsula ◽  
Ecological Niches ◽  
Microsatellite Data ◽  
Species Status ◽  
Island Effect ◽  
Ecological Variables ◽  
True Diversity ◽  
Candidate Species ◽  
Related Individuals

Closely related individuals from different areas can see their morphologies change based on differences between clades, but also ecological variables such as the island effect or sympatry. This is the case of salamanders, which have adapted to a broad range of ecological niches, ranging from underground dwellers in xeric landscape to tropical arboreal habitats. On the Korean Peninsula, salamanders from the Hynobius clade are widespread on the mainland and islands, with several partially sympatric clades and candidate species. Currently, seven lineages have been identified based on mtDNA, four of them matching named species and three others for which the species status remains untested. While the morphology of Korean Hynobius is known to be variable between genetically segregated clades, we hypothesise that (1) the candidate species are morphologically different, and that (2) the island effect and (3) the sympatric status have significant impacts on the morphology of individuals within the genus. Here we measured 329 Hynobius salamanders from all seven clades, in areas of sympatry and allopatry, and on islands and on the mainland (Graphical Abstract A). We determined that the island effect had a significant impact on the morphology of the genus, with mainland individuals generally displaying a broader range of morphology than islandic individuals (Graphical Abstract B). We also determined that sympatry had an impact on morphology, with the sizes of individuals from clades in sympatric areas diverging from each other (Graphical Abstract C). Finally, we demonstrated that all seven clades have significantly different morphologies, and we described the three candidate species that had already been isolated based on mtDNA and microsatellite data: Hynobius notialis sp. nov., Hynobius geojeensis sp. nov. and Hynobius perplicatus sp. nov. We conclude that looking at morphology alone would be misleading about the true diversity of Hynobius species, and species in general, because of the island and patry effects.

scholarly journals DELAYED LIGHT PRODUCTION BY BLUE-GREEN ALGAE, RED ALGAE, AND PURPLE BACTERIA

1956 ◽  
Vol 39 (3) ◽  
pp. 311-318 ◽  
Author(s):  
William Arnold ◽  
Jane Thompson
Keyword(s):  
Emission Spectrum ◽  
Green Algae ◽  
Red Algae ◽  
Purple Bacteria ◽  
Action Spectrum ◽  
Broad Band ◽  
Emission Spectra ◽  
Blue Green Algae ◽  
Action Spectra ◽  
Light Production

1. Blue-green algae, red algae, and purple bacteria all show the emission of delayed light. 2. The action spectra for the production of delayed light by three species of blue-green algae have one broad band with a peak at 620 mµ. 3. The action spectrum for production of delayed light by the red algae has one peak at 550 mµ with a shoulder from 600 to 660 mµ. 4. The emission spectra of the delayed light from both the blue-green and red algae were the same as from the green algae, Chlorella. 5. The action spectra for the production of delayed light by the different species of purple bacteria tested consisted of one or more bands not resolved between 800 and 900 mµ. 6. The emission spectrum of the delayed light from the purple bacteria was largely at wave lengths longer than 900 mµ.

Two cyanobacterial strains can be distinguished from each other and other eukaryotic algae by spectral absorption method

2011 ◽  
Vol 63 (6) ◽  
pp. 1203-1210 ◽  
Author(s):  
Asha U. M. Lokuhewage ◽  
T. Fujino
Keyword(s):  
Green Algae ◽  
Algal Species ◽  
Regression Analyses ◽  
Absorption Method ◽  
Spectral Absorption ◽  
Freshwater Algae ◽  
Blue Green Algae ◽  
Eukaryotic Algae ◽  
Freshwater Bodies ◽  
Kanto Region

Spectral absorption method based on two step linear regression analyses (TSLR) was applied for detection of two strains of cyanobacterium, Microcystis (blue-green algae) from eukaryotic algae. Both blue-green algae, algae and dissolved organic carbon (DOC) were considered from freshwater bodies in Kanto region, Japan. The results show that blue-green species can be detected from other algal species using absorption spectra of water samples. In this study statistical analysis was done by TSLR method, which determined the gradient vectors of single algal species and DOC. We believe that this method might be useful in environmental monitoring of freshwater algae.

scholarly journals Novel diversity within marine Mamiellophyceae (Chlorophyta) unveiled by metabarcoding

2018 ◽  
Author(s):  
Margot Tragin ◽  
Daniel Vaulot
Keyword(s):  
Phylogenetic Analyses ◽  
18S Rrna Gene ◽  
Ecological Niches ◽  
Rrna Gene ◽  
Green Microalgae ◽  
Variable Regions ◽  
Specific Distribution ◽  
Clade B ◽  
Candidate Species ◽  
Ocean Sampling

ABSTRACTThe Ocean Sampling Day (OSD) project provided metabarcoding data for the V4 hyper-variable regions of the 18S rRNA gene from 157 samples collected at 143 mostly coastal stations. In this paper we focus on the class Mamiellophyceae, which was found at nearly all OSD stations and represented 55 % of the green microalgae (Chlorophyta) reads in the 2014 OSD dataset. We performed phylogenetic analyses of unique OSD metabarcodes (ASV, amplicon single variants) and reference GenBank sequences from cultures and from the environment, focusing on the four most represented genera: Ostreococcus (45 % of the Mamiellophyceae reads), Micromonas (34 %), Bathycoccus (10 %) and Mantoniella (8.7 %). These analyses uncovered novel diversity within each genus except Bathycoccus. In Ostreococcus, a new clade (E) with 2 very clear base pair differences compared to the oceanic clade B in the V4 region was the second most represented clade after the coastal Ostreococcus “lucimarinus”. Within Micromonas, ten clades were found exceeding the 4 species and 2 candidate species already described. Finally, we found 2 new environmental clades of Mantoniella. Each Mamiellophyceae clade had a specific distribution in the OSD dataset suggesting that they are adapted to different ecological niches.

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