scholarly journals Allelopathic activity of the picocyanobacterium Synechococcus sp. on unicellular eukaryote planktonic microalgae

2018 ◽  
Vol 69 (9) ◽  
pp. 1472 ◽  
Author(s):  
Sylwia Śliwińska-Wilczewska ◽  
Aldo Barreiro Felpeto ◽  
Jakub Maculewicz ◽  
Amanda Sobczyk ◽  
Vitor Vasconcelos ◽  
...  
Keyword(s):  
Photosynthetic Rate ◽  
Unicellular Eukaryote ◽  
Allelopathic Effect ◽  
Prymnesium Parvum ◽  
Porphyridium Purpureum ◽  
Allelopathic Activity ◽  
Wide Range ◽  
Synechococcus Sp ◽  
Taxonomic Groups ◽  
Allelopathic Compounds

The production and release of allelopathic compounds is an important adaptation by which some species of cyanobacteria can achieve a competitive advantage over other primary producers. In the present study we tested the allelopathic activity of the picocyanobacterium Synechococcus sp. against the following coexisting unicellular eukaryote microalgae: Porphyridium purpureum, Stichococcus bacillaris, Prymnesium parvum and Nitzschia dissipata. With these species, we covered a wide range of taxonomic groups. We demonstrated that both the addition of Synechococcus sp. cell-free filtrate and coculture inhibited the growth, chlorophyll content and photosynthetic rate of P. purpureum and S. bacillaris. Conversely, P. parvum, a well-known mixotroph, was positively affected by both Synechococcus sp. treatments. In contrast, N. dissipata was not affected by either the picocyanobacterial filtrate or coculture. These results suggest that the negative allelopathic effect is related to a reduction in the photosynthetic rate, and that Synechococcus sp. allelopathy should be taken into account in the interactions between picocyanobacteria and eukaryote competitors coexisting in a planktonic system.

scholarly journals Assessment of the Allelochemical Activity and Biochemical Profile of Different Phenotypes of Picocyanobacteria from the Genus Synechococcus

Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 179 ◽  
Author(s):  
Zofia Konarzewska ◽  
Sylwia Śliwińska-Wilczewska ◽  
Aldo Barreiro Felpeto ◽  
Vitor Vasconcelos ◽  
Adam Latała
Keyword(s):  
Green Algae ◽  
Allelopathic Effect ◽  
Relevant Role ◽  
Biochemical Profiles ◽  
Strain Type ◽  
Synechococcus Sp ◽  
Cell Free Filtrate ◽  
Allelopathic Compounds

Organisms belonging to Synechococcus sp. genera are observed in all freshwater, brackish, and marine waters of the world. They play a relevant role in these ecosystems, since they are one of the main primary producers, especially in open ocean. Eventually, they form mass blooms in coastal areas, which are potentially dangerous for the functioning of marine ecosystems. Allelopathy could be an important factor promoting the proliferation of these organisms. According to the authors’ best knowledge, there is no information on the allelopathic activity and allelopathic compounds exhibited by different Synechococcus sp. phenotypes. Therefore, the research conducted here aimed to study the bioactivity of compounds produced by three phenotypes of Synechococcus sp. by studying their influence on the growth, chlorophyll fluorescence, and photosynthetic pigments of eighteen cyanobacteria and microalgae species. We demonstrated that three different Synechococcus sp. phenotypes, including a phycocyanin (PC)-rich strain (Type 1; green strain) and phycoerythrin (PE)-rich strains containing phycoerythrobilin (PEB) and phycocyanobilin (PCB) (Type 2; red strain and Type 3a; brown strain), had a significant allelopathic effect on the selected species of cyanobacteria, diatoms, and green algae. For all green algae, a decrease in cell abundance under the influence of phenotypes of donor cyanobacteria was shown, whereas, among some target cyanobacteria and diatom species, the cell-free filtrate was observed to have a stimulatory effect. Our estimates of the stress on photosystem II (Fv/Fm) showed a similar pattern, although for some diatoms, there was an effect of stress on photosynthesis, while a stimulatory effect on growth was also displayed. The pigment content was affected by allelopathy in most cases, particularly for chlorophyll a, whilst it was a bit less significant for carotenoids. Our results showed that Synechococcus sp. Type 3a had the strongest effect on target species, while Synechococcus sp. Type 1 had the weakest allelopathic effect. Furthermore, GC-MS analysis produced different biochemical profiles for the Synechococcus strains. For every phenotype, the most abundant compound was different, with oxime-, methoxy-phenyl- being the most abundant substance for Synechococcus Type 1, eicosane for Synechococcus Type 2, and silanediol for Synechococcus Type 3a.

The Dose Determines the Stimulation (and Poison): Development of A Chemical Hormesis Database

1997 ◽  
Vol 16 (6) ◽  
pp. 545-559 ◽  
Author(s):  
Edward J. Calabrese ◽  
Linda A. Baldwin
Keyword(s):  
A Priori ◽  
Dose Range ◽  
Evaluation Criteria ◽  
Metabolic Effects ◽  
Growth Responses ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Real Phenomenon ◽  
Effect Level ◽  
Taxonomic Groups

A comprehensive effort was undertaken to identify articles demonstrating chemical hormesis. Nearly 4000 potentially relevant articles were retrieved from preliminary computer searches utilizing various keyword descriptors and extensive cross-referencing. A priori evaluation criteria were established including study design features (e.g., number of doses, dose range), statistical analysis, and reproducibility of results. Evidence of chemical hormesis was judged to have occurred in approximately 350 of the 4000 studies evaluated. Chemical hormesis was observed in a wide range of taxonomic groups and involved agents representing highly diverse chemical classes, many of potential environmental relevance. Numerous biologic endpoints were assessed, with growth responses the most prevalent, followed by metabolic effects, longevity, reproductive responses, and survival. Hormetic responses were generally observed to be of limited magnitude with the average low-dose maximum stimulation approximately 50% greater than controls. The hormetic dose-response range was generally limited to about one order of magnitude with the upper end of the hormetic curve approaching the estimated no-observed-effect level (NOEL) for the particular endpoint. Based on the evaluation criteria, high to moderate evidence of hormesis was observed in studies comprised of ≥ doses with <3 doses in the hormetic zone. The present analysis suggests that chem ical hormesis is a reproducible and generalizable biologic phenomenon. Over the last decade advances have been made providing mechanistic insight helpful in explaining the phenomenon of chemical hormesis in multiple biologic systems with various endpoints. The reason for the uncertainty surrounding the existence of hormesis as a “real phenomenon” is believed to be the result of its relatively infrequent observation in the literature due to experimental design considerations, especially with respect to the number of doses, range of doses, and endpoint selection.

scholarly journals Lanthanide-Dependent Methylotrophs of the Family Beijerinckiaceae: Physiological and Genomic Insights

2019 ◽  
Vol 86 (1) ◽  
Author(s):  
Carl-Eric Wegner ◽  
Linda Gorniak ◽  
Stefan Riedel ◽  
Martin Westermann ◽  
Kirsten Küsel
Keyword(s):  
Methanol Oxidation ◽  
Carbon Assimilation ◽  
Methylotrophic Bacteria ◽  
Alcohol Dehydrogenases ◽  
New Members ◽  
Physiological Diversity ◽  
Wide Range ◽  
Low Mass ◽  
Taxonomic Groups ◽  
Methylated Sulfur Compounds

ABSTRACT Methylotrophic bacteria use methanol and related C1 compounds as carbon and energy sources. Methanol dehydrogenases are essential for methanol oxidation, while lanthanides are important cofactors of many pyrroloquinoline quinone-dependent methanol dehydrogenases and related alcohol dehydrogenases. We describe here the physiological and genomic characterization of newly isolated Beijerinckiaceae bacteria that rely on lanthanides for methanol oxidation. A broad physiological diversity was indicated by the ability to metabolize a wide range of multicarbon substrates, including various sugars, and organic acids, as well as diverse C1 substrates such as methylated amines and methylated sulfur compounds. Methanol oxidation was possible only in the presence of low-mass lanthanides (La, Ce, and Nd) at submicromolar concentrations (>100 nM). In a comparison with other Beijerinckiaceae, genomic and transcriptomic analyses revealed the usage of a glutathione- and tetrahydrofolate-dependent pathway for formaldehyde oxidation and channeling methyl groups into the serine cycle for carbon assimilation. Besides a single xoxF gene, we identified two additional genes for lanthanide-dependent alcohol dehydrogenases, including one coding for an ExaF-type alcohol dehydrogenase, which was so far not known in Beijerinckiaceae. Homologs for most of the gene products of the recently postulated gene cluster linked to lanthanide utilization and transport could be detected, but for now it remains unanswered how lanthanides are sensed and taken up by our strains. Studying physiological responses to lanthanides under nonmethylotrophic conditions in these isolates as well as other organisms is necessary to gain a more complete understanding of lanthanide-dependent metabolism as a whole. IMPORTANCE We supplemented knowledge of the broad metabolic diversity of the Beijerinckiaceae by characterizing new members of this family that rely on lanthanides for methanol oxidation and that possess additional lanthanide-dependent enzymes. Considering that lanthanides are critical resources for many modern applications and that recovering them is expensive and puts a heavy burden on the environment, lanthanide-dependent metabolism in microorganisms is an exploding field of research. Further research into how isolated Beijerinckiaceae and other microbes utilize lanthanides is needed to increase our understanding of lanthanide-dependent metabolism. The diversity and widespread occurrence of lanthanide-dependent enzymes make it likely that lanthanide utilization varies in different taxonomic groups and is dependent on the habitat of the microbes.

Zooplankton growth and survival differentially respond to interactive warming and acidification effects

2020 ◽  
Vol 42 (2) ◽  
pp. 189-202
Author(s):  
Jessica Garzke ◽  
Ulrich Sommer ◽  
Stefanie M H Ismar-Rebitz
Keyword(s):  
Ocean Acidification ◽  
Single Species ◽  
Functional Trait ◽  
Trophic Levels ◽  
Growth And Survival ◽  
Geographical Regions ◽  
Wide Range ◽  
Set Up ◽  
Taxonomic Groups ◽  
Zooplankton Growth

Abstract The copepod Acartia tonsa is a key component of a wide range of marine ecosystems, linking energy transfer from phytoplankton to higher trophic levels, and has a central role in productivity and biogeochemistry. The interaction of end-of-century global warming and ocean acidification scenarios with testing moderate temperature effects on a seminatural copepod community is needed to understand future community functioning. Here, we deployed a mesocosm experimental set-up with a full factorial design using two temperatures (13°C and 19°C) crossed with a pCO2 gradient ranging from ambient (550 μatm) to 3000 μatm. We used the natural bacteria, phyto- and microzooplankton species composition and biomass of the Kiel Bight and tested the response of A. tonsa development, carbon growth, mortality, size and condition. The tested traits were differently affected by the interaction of temperature and acidification. Ocean acidification increased development, carbon growth, size and mortality under the warming scenario of 19°C. At 13°C mortality rates decreased, while carbon growth, size and condition increased with acidification. We conclude from our experimental approach that a single species shows a variety of responses depending on the focal functional trait. Trait-specific mesozooplankton responses need to be further investigated and compared between geographical regions, seasons and taxonomic groups.

The elevation gradient of lichen species richness in Nepal

2009 ◽  
Vol 42 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Chitra Bahadur BANIYA ◽  
Torstein SOLHØY ◽  
Yngvar GAUSLAA ◽  
Michael W. PALMER
Keyword(s):  
Species Richness ◽  
Endemic Species ◽  
Elevation Gradient ◽  
Distribution Patterns ◽  
Lichen Species ◽  
Ecological Niches ◽  
Published Data ◽  
Elevation Gradients ◽  
Wide Range ◽  
Taxonomic Groups

AbstractThis study of elevation gradients of lichen species richness in Nepal aimed to compare distribution patterns of different life-forms, substratum affinities, photobiont types, and Nepalese endemism. Distribution patterns of lichens were compared with elevational patterns shown by a wide range of taxonomic groups of plants along the Nepalese Himalayan elevational gradient between 200–7400m. We used published data on the elevation records of 525 Nepalese lichen species to interpolate presence between the maximum and minimum recorded elevations, thereby giving estimates of lichen species richness at each 100-m elevational band. The observed patterns were compared with previously published patterns for other taxonomic groups. The total number of lichens as well as the number of endemic species (55 spp.) showed humped relationships with elevation. Their highest richness was observed between 3100–3400 and 4000–4100m, respectively. Almost 33% of the total lichens and 53% of the endemic species occurred above the treeline (>4300m). Non-endemic richness had the same response as the total richness. All growth forms showed a unimodal relationship of richness with elevation, with crustose lichens having a peak at higher elevations (4100–4200m) than fruticose and foliose lichens. Algal and cyanobacterial lichen richness, as well as corticolous lichen richness, all exhibited unimodal patterns, whereas saxicolous and terricolous lichen richness exhibited slightly bimodal relationships with elevation. The highest lichen richness at mid altitudes concurred with the highest diversity of ecological niches in terms of spatial heterogeneity in rainfall, temperature, cloud formation, as well as high phorophyte abundance and diversity implying large variation in bark roughness, moisture retention capacity, and pH. The slightly bimodal distributions of saxicolous and terricolous lichens were depressed at the elevational maximum of corticolous lichens.

The distributions of a wide range of taxonomic groups are expanding polewards

2006 ◽  
Vol 12 (3) ◽  
pp. 450-455 ◽  
Author(s):  
RACHAEL HICKLING ◽  
DAVID B. ROY ◽  
JANE K. HILL ◽  
RICHARD FOX ◽  
CHRIS D. THOMAS
Keyword(s):  
Wide Range ◽  
Taxonomic Groups

scholarly journals Viruses infecting main ornamental plants: an overview

2018 ◽  
Vol 24 (2) ◽  
pp. 95-102 ◽  
Author(s):  
Irina Vjacheslavovna Mitrofanova ◽  
Alexsandr Vladimirovich Zakubanskiy ◽  
Olga Vladimirovna Mitrofanova
Keyword(s):  
Negative Impact ◽  
Ornamental Plants ◽  
Plant Viruses ◽  
Economic Damage ◽  
Urban Landscapes ◽  
Wide Range ◽  
Significant Negative Impact ◽  
Plant Viruses And Viroids ◽  
Taxonomic Groups

Ornamental plants are cultivated for decorative and utility purposes in urban landscapes throughout the world. They are much valued for their aesthetic properties and constitute an important part of the global horticulture industry. Plant viruses and viroids of various taxonomic groups have a significant negative impact on ornamentals provoking a wide range of symptoms, reducing both decorative value and quality of propagated material and causing large economic damage. A significant growth of the ornamental plants market in recent years promotes the spread of viral diseases. Therefore, systematization of data on virus and viroid phytopathogens diversity in these cultures is an urgent research task. Among the most popular ornamentals are chrysanthemum, rose, clematis, canna, and lavender. More than fifty viruses and viroids from 17 different families (including two viroid families) have been identified in these crops to date. In the presented review, we described the variety of these pathogens and their effect on the above-mentioned ornamentals

scholarly journals Allelopathic effect of the Baltic picocyanobacterium Synechococcus sp. on selected diatoms

2017 ◽  
Author(s):  
Zofia Konarzewska ◽  
Sylwia Śliwińska-Wilczewska ◽  
Adam Latała
Keyword(s):  
Quantum Yield ◽  
Algal Blooms ◽  
Allelopathic Effect ◽  
Effective Quantum Yield ◽  
Fluorescence Parameters ◽  
Psii Photochemistry ◽  
Synechococcus Sp ◽  
The Baltic ◽  
Allelopathic Interactions ◽  
Quantum Yield Of Psii

It is commonly believed that the structure of phytoplankton and the formation of cyanobacterial and algal blooms may be explained by allelopathic interactions. The main aim of this study was to investigate the allelopathic effect of picocyanobacterium Synechococcus sp. on the following growth and fluorescence parameters: the maximum quantum yield of PSII photochemistry (Fv/Fm), and the effective quantum yield of PSII photochemistry (ΦPSII) of selected diatoms – Nitzschia fonticola, Fistulifera saprophila, Navicula perminuta and Amphora coffeaeformis. In this study, it was demonstrated that picocyanobacterium caused allelopathic effects against Baltic diatoms. The results showed that the addition of cell-free filtrate from Synechococcus sp. increased the number of cells of N. fonticola and F. saprophila. Moreover, it was found that picocyanobacterium was stimulated fluorescence parameters of N. fonticola, F. saprophila, and N. perminuta. On the other hand, it was noted that filtrate obtained from picocyanobacterium caused the inhibition of Fv/Fm parameter of A. coffeaeformis. The results of this experiment may provide further information about allelopathic interactions between Baltic picocyanobacteria and diatoms that are crucial to the understanding of algal blooms in aquatic ecosystems.

scholarly journals Evaluation of allelopathic competency of Lamium amplexicaule and identification of its allelopathic active substance

2019 ◽  
pp. 76
Author(s):  
Chisato Sakamoto, Masahiko Suzuki ◽  
Arihiro Iwasaki, Kiyotake Suenaga ◽  
Hisashi Kato- Noguchi
Keyword(s):  
Shoot Growth ◽  
Lolium Multiflorum ◽  
Lepidium Sativum ◽  
Allelopathic Effect ◽  
Chromatographic Separations ◽  
Allelopathic Potential ◽  
Arctium Lappa ◽  
Allelopathic Activity ◽  
Root And Shoot Growth ◽  
Methyl Caffeate

The weedy annual grass Lamium amplexicaule (L.) originated from the Mediterranean region, spreads quickly, and becomes naturalized in areas it invades. It was assumed that volatile phytotoxic substances are one of the invasive characteristics of L. amplexicaule. However, no volatile compound has been found. Therefore, we re-evaluated the allelopathic potential of L. amplexicaule and investigated the phytotoxic substances with allelopathic activity. An extract of L. amplexicaule inhibited the root and shoot growth of Lepidium sativum, Lactuca sativa, Arctium lappa, Lolium multiflorum Lam., Echinochloa crus-galli, and Vulpia myuros, which indicates that the extract has an allelopathic effect. The extract was purified using bioassay-guided chromatographic separations, and a phytotoxic substance with allelopathic activity was isolated and characterized as methyl caffeate. The compound significantly inhibited the root and shoot growth of L. sativum and L. multiflorum. The present results suggest that methyl caffeate may contribute to the allelopathic effect of the L. amplexicaule extracts and consequently, may be partly responsible for the invasive characteristics of the species. 

scholarly journals Rapid assessment of the suitability of multi-species citizen science datasets for occupancy trend analysis

2019 ◽  
Author(s):  
Michael J.O. Pocock ◽  
Mark W. Logie ◽  
Nick J.B. Isaac ◽  
Charlotte L. Outhwaite ◽  
Tom August
Keyword(s):  
Great Britain ◽  
Citizen Science ◽  
Expert Elicitation ◽  
List Type ◽  
Occupancy Models ◽  
Science Data ◽  
Focal Species ◽  
Wide Range ◽  
Simple Rules ◽  
Taxonomic Groups

AbstractSpecies records from volunteers are a vast and valuable source of information on biodiversity for a wide range of taxonomic groups. Although these citizen science data are opportunistic and unstructured, occupancy analysis can be used to quantify trends in distribution. However, occupancy analysis of unstructured data can be resource-intensive and requires substantial expertise. It is valuable to have simple ‘rules of thumb’ to efficiently assess the suitability of a dataset for occupancy analysis prior to analysis.Our analysis was possible due to the production of trends, from our Bayesian occupancy analysis, for 10 967 species from 34 multi-species recording schemes in Great Britain. These schemes had an average of 500 visits to sites per year, and an average of 20% of visited sites received a revisit in a year. Occupancy trend outputs varied in their precision and we used expert elicitation on a subset of outputs to determine a precision threshold above which trends were suitable for further consideration. We then used classification trees with seven metrics to define simple rules explaining when the data would result in outputs that met the precision threshold.We found that the suitability of a species’ data was best described by (i) the number of records of the focal species in the 10% best-recorded years, and (ii) the proportion of recording visits for that taxonomic group with non-detections of the focal species. Surprisingly few data were required to be predicted to meet the precision threshold. Specifically, for 98% confidence that our Bayesian occupancy models would produce outputs meeting the precision threshold, there needed to be ≥29 records of the focal species in the 10% best-recorded years (equivalent to an average of 12.5 records per year in our dataset), although only ≥10 records (equivalent to 4.5 records per year) were required for species recorded in less than 1 in 25 visits.We applied these rules to regional species data for Great Britain. Data from 32% of the species:region combinations met the precision threshold with 80% confidence, and 14% with 98% confidence. There was great variation between taxonomic groups (e.g. butterflies, moths and dragonflies were well recorded) and region (e.g. south-east England was best recorded).These simple criteria provide no indication of the accuracy or representativeness of the trend outputs: this is vital, but needs to be assessed individually. However our criteria do provide a rapid, quantitative assessment of the predicted suitability of existing data for occupancy analysis and could be used to inform the design and implementation of multi-species citizen science recording projects elsewhere in the world.

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