scholarly journals Persistence of microcystin production of Planktothrix agardhii exposed to different salinity concentrations

2018 ◽  
Author(s):  
Julia Vergalli ◽  
Audrey Combes ◽  
Evelyne Franquet ◽  
Stéphanie Fayolle ◽  
Katia Comte

ABSTRACTRecent reports tend to predict the increase of harmful cyanobacteria in water systems worldwide due to the climatic and environmental changes, which would compromise water quality and public health. Among abiotic changes, the higher salinities are expected to promote the growth of some harmful species such as Planktothrix agardhii, which is known to build up blooms in brackish areas. Since P. agardhii is a common cyanotoxin producer (microcystin-producing), we investigated here the growth and tolerance of this species when exposed in vitro to a range of salinity levels, while assessing its microcystins variation and production in batch cultures during a time-frame experiment of 18 days. The study revealed a salt acclimation of the brackish P. agardhii that still produced microcystins in salty cultures while maintaining its growth ability in low to medium salinities (ranged from 0 to 7.5 g L−1). For higher salinity concentrations (10 to 12.5 g L−1), microcystins were still detected, while significantly lower growth rates were obtained during the exponential growth phase. This suggests that moderate to high salt ranges do not inhibit the microcystins production of P. agardhii at least for several weeks. Finally, the predicted remediation perspectives in a context of environment salinization assumed by environmental policies may be insufficient to eradicate this potential toxic cyanobacteria, especially when this species is already dominant in the waterbodies.

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 225-225
Author(s):  
C. L. Rosser ◽  
L. Jin ◽  
K. A. Beauchemin ◽  
M. Oba ◽  
S. M. Cutting ◽  
...  
Keyword(s):  

2019 ◽  
Vol 20 (10) ◽  
pp. 2500 ◽  
Author(s):  
Vrathasha Vrathasha ◽  
Hilary Weidner ◽  
Anja Nohe

Background: Osteoporosis is a degenerative skeletal disease with a limited number of treatment options. CK2.3, a novel peptide, may be a potential therapeutic. It induces osteogenesis and bone formation in vitro and in vivo by acting downstream of BMPRIA through releasing CK2 from the receptor. However, the detailed signaling pathways, the time frame of signaling, and genes activated remain largely unknown. Methods: Using a newly developed fluorescent CK2.3 analog, specific inhibitors for the BMP signaling pathways, Western blot, and RT-qPCR, we determined the mechanism of CK2.3 in C2C12 cells. We then confirmed the results in primary BMSCs. Results: Using these methods, we showed that CK2.3 stimulation activated OSX, ALP, and OCN. CK2.3 stimulation induced time dependent release of CK2β from BMPRIA and concurrently CK2.3 colocalized with CK2α. Furthermore, CK2.3 induced BMP signaling depends on ERK1/2 and Smad1/5/8 signaling pathways. Conclusion: CK2.3 is a novel peptide that drives osteogenesis, and we detailed the molecular sequence of events that are triggered from the stimulation of CK2.3 until the induction of mineralization. This knowledge can be applied in the development of future therapeutics for osteoporosis.


Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 932
Author(s):  
Julia Brockhaus ◽  
Rogerio B. Craveiro ◽  
Irma Azraq ◽  
Christian Niederau ◽  
Sarah K. Schröder ◽  
...  

Human Periodontal Ligament Fibroblasts (hPDLF), as part of the periodontal apparatus, modulate inflammation, regeneration and bone remodeling. Interferences are clinically manifested as attachment loss, tooth loosening and root resorption. During orthodontic tooth movement (OTM), remodeling and adaptation of the periodontium is required in order to enable tooth movement. hPDLF involvement in the early phase-OTM compression side was investigated for a 72-h period through a well-studied in vitro model. Changes in the morphology, cell proliferation and cell death were analyzed. Specific markers of the cell cycle were investigated by RT-qPCR and Western blot. The study showed that the morphology of hPDLF changes towards more unstructured, unsorted filaments under mechanical compression. The total cell numbers were significantly reduced with a higher cell death rate over the whole observation period. hPDLF started to recover to pretreatment conditions after 48 h. Furthermore, key molecules involved in the cell cycle were significantly reduced under compressive force at the gene expression and protein levels. These findings revealed important information for a better understanding of the preservation and remodeling processes within the periodontium through Periodontal Ligament Fibroblasts during orthodontic tooth movement. OTM initially decelerates the hPDLF cell cycle and proliferation. After adapting to environmental changes, human Periodontal Ligament Fibroblasts can regain homeostasis of the periodontium, affecting its reorganization.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1192
Author(s):  
Francesco Tini ◽  
Giovanni Beccari ◽  
Gianpiero Marconi ◽  
Andrea Porceddu ◽  
Micheal Sulyok ◽  
...  

DNA methylation mediates organisms’ adaptations to environmental changes in a wide range of species. We investigated if a such a strategy is also adopted by Fusarium graminearum in regulating virulence toward its natural hosts. A virulent strain of this fungus was consecutively sub-cultured for 50 times (once a week) on potato dextrose agar. To assess the effect of subculturing on virulence, wheat seedlings and heads (cv. A416) were inoculated with subcultures (SC) 1, 23, and 50. SC50 was also used to re-infect (three times) wheat heads (SC50×3) to restore virulence. In vitro conidia production, colonies growth and secondary metabolites production were also determined for SC1, SC23, SC50, and SC50×3. Seedling stem base and head assays revealed a virulence decline of all subcultures, whereas virulence was restored in SC50×3. The same trend was observed in conidia production. The DNA isolated from SC50 and SC50×3 was subject to a methylation content-sensitive enzyme and double-digest, restriction-site-associated DNA technique (ddRAD-MCSeEd). DNA methylation analysis indicated 1024 genes, whose methylation levels changed in response to the inoculation on a healthy host after subculturing. Several of these genes are already known to be involved in virulence by functional analysis. These results demonstrate that the physiological shifts following sub-culturing have an impact on genomic DNA methylation levels and suggest that the ddRAD-MCSeEd approach can be an important tool for detecting genes potentially related to fungal virulence.


2015 ◽  
Vol 3 (3) ◽  
pp. 552-560 ◽  
Author(s):  
Mohamed A.M. El-Awady ◽  
Mohamed M. Hassan ◽  
Yassin M. Al-Sodany

This study was designed to isolate and characterize endophytic and rhizospheric bacteria associated with the halophyte plant Sesuvium verrucosum, grown under extreme salinity soil in Jeddah, Saudi Arabia. The plant growth promotion activities of isolated bacterial were evaluated in vitro. A total of 19 salt tolerant endophytic and rhizospheric bacterial isolates were obtained and grouped into six according to genetic similarity based on RAPD data. These six isolates were identified by amplification and partial sequences of 16S rDNA as Enterobacter cancerogenus,Vibrio cholerae, Bacillus subtilis, Escherichia coli and two Enterobacter sp. Isolates were then grown until exponential growth phase to evaluate the atmospheric nitrogen fixation, phosphate solubilization, and production of phytohormones such as indole-3-acetic acid, as well as 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. While, All of the six strains were negative for ACC deaminaseactivity, two isolates showed Nitrogen fixation activity, three isolates produce the plant hormone (Indole acetic acid) and two isolates have the activity of solubiliztion of organic phosphate. Among the six isolates, the isolate (R3) from the soil around the roots is able to perform the three previous growth promoting possibilities together and it is ideal for use in promoting the growth of plants under the high salinity conditions. This isolate is candidate to prepare a friendly biofertelizer that can be used for the improvement of the crops performance under salinity conditions.Int J Appl Sci Biotechnol, Vol 3(3): 552-560


2002 ◽  
Vol 50 (8) ◽  
pp. 1059-1065 ◽  
Author(s):  
Sherri R. Davies ◽  
Shinji Sakano ◽  
Yong Zhu ◽  
Linda J. Sandell

The control of extracellular matrix (ECM) production is important for the development, maintenance, and repair of cartilage tissues. Matrix molecule synthesis is generally regulated by the rate of gene transcription determined by DNA transcription factors. We have shown that transcription factors Sox9, AP-2, and [delta]EF1 are able to alter the rate of CD-RAP transcription in vitro: Sox9 upregulates, AP-2 exhibits biphasic effects, and [delta]EF1 represses expression of the CD-RAP gene. To correlate these in vitro activities in vivo, transcription factors were co-immunolocalized with ECM proteins in three different cartilage tissues in which the rates of biosynthesis are quite different: articular, meniscal, and growth plate. Immunoreactivities of type II collagen and CD-RAP were higher in growth plate than in either the articular or meniscal cartilages and correlated positively with Sox9 protein. Sox9 staining decreased with hypertrophy and was low in articular and meniscal cartilages. In contrast, AP-2 and [delta]EF1 were low in proliferating chondrocytes but high in lower growth plate, articular, and meniscal cartilages. This increase was also accompanied by intense nuclear staining. These immunohistochemical results are the first to localize both [delta]EF1 and AP-2 to adult articular, meniscal, and growth plate cartilages and provide in vivo correlation of previous molecular biological studies.


2008 ◽  
Vol 33 (1) ◽  
pp. 95-100
Author(s):  
Nining Betawati Prihantini ◽  
Arya Widyawan ◽  
Ronny Rianto ◽  
Yuni Ariyani ◽  
Wishnu Wardhana ◽  
...  

The research was aimed to understand the composition and dominancy of aquatic microalgae, and to know the potential toxicity of Cyanobacteria occuring in three lakes of Jakarta-Bogor area. The study was done in 2006. The sampling sites were Lake Sunter 2 (North Jakarta), Lake Babakan (South Jakarta), and Lake Lido (Bogor). The water samples were taken using plankton-net (20 tan mesh) with horizontal tow. The results showed that. the number of microalgal genera in Sunter 2, Babakan, and Lido were different, i.e. 10 genera, 40 genera, and 14 genera, respectively. Cyanobacteria were dominant in Sunter 2 (96%) and Babakan (90.01%). The dominant Cyanobacteria in Sunter 2 was Planktothrix agardhii (53.48%), whereas in Babakan was Chroococcus dispersus (68.52%). The second abundant Cyanobacteria in Sunter 2 was Arthrospira (42.54%). Planktothrix agardhii and Arthrospira are known to produce harmful toxin.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Dalan Jing ◽  
Yingyu Li ◽  
Ziyuan Liu ◽  
Chen Huang ◽  
Pei Zhang ◽  
...  

Purpose. The biological characteristics of Fusarium solani clinical corneal isolates growing in different nutritional conditions in vitro were studied in order to find out the key point of pathogenicity. Methods. Five kinds of media with different glucose and nitrogen concentrations were prepared as the liquid and solid forms. The clinical isolates were as follows: 2 Fusarium solani strains. The clinical corneal isolates and the standard strains were inoculated in the solid and liquid media. They were all incubated at 296 for 96 h and observed at defined time points. The optical density was recorded to generate the growth curves in liquid media. Morphologic changes of colonies in the solid media were determined under the light microscope. Results. The clinical isolates of Fusarium solani showed stronger reproductive capacity in the abominable nutritional condition. Besides, when the glucose concentration in the medium was consistent with the glucose concentration of aqueous in diabetic patients, the clinical isolates would show the biological features of quicker growth rate and stronger reproductive capacity. Conclusions. Nitrogen source is essential for fungus reproduction. The clinical isolates showed stronger environmental adaptability under different nutritional conditions and more sensitive to environmental changes.


2017 ◽  
Vol 50 (3) ◽  
pp. 95-105 ◽  
Author(s):  
V. Rameeh ◽  
M. Gerami ◽  
V. Ghasemi Omran ◽  
S. Ghavampour

Abstract Stevia (Stevia rebaudiana Bertoni), with great potential as a natural sweeteners source, has a high content of sweeteners, which are up to 150 times sweeter than sugar, but virtually with no calories. Stevia also suitable to be cultivated in semiarid climates and coastal areas, which are characterized by the low quality of the irrigation water. Soil salinity occupies a prominent place among the soil problems that threaten the sustainability of agriculture over a vast area in the world. Glycine betaine is an osmoprotectant, that plays an important role and accumulates rapidly in many plants during salinity or drought stress. In order to evaluation of glycine betaine amending effects on salinity stress in stevia under in vitro condition, a factorial experiment was conducted in 2015. Four NaCl levels, including 0, 50, 75 and 100 mM, along with 0, 1, 12.5, 25 and 50 mM of glycine betaine concentrations were used in Murashige and Skoog (MS) medium. The results showed that salinity levels had significant reduction effects on plant height, root length, shoot fresh weight, number of leaf, total chlorophyll, rebaudioside A and stevioside of the stevia genotype. Due to increasing of glycine betaine, levels all the traits were increased. Owing to amending effect of glycine betaine, its high concentrations made less hazarding effects of salinity on the researched traits. The highest mean value of rebaudioside A (10.62rt) and stevioside (23.38rt) determined at 50 mM of glycine betaine with 0 mM of NaCl concentration.


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