Lyngbya Majuscula Research Articles

Aquatic Antagonists: Seaweed Dermatitis (Lyngbya majuscula).

The cyanobacterium Lyngbya majuscula grows in marine and estuarine environments across the world and produces many biologically active compounds. Direct contact with L majuscula and its dermatoxins can cause seaweed dermatitis, which manifests as a papulovesicular eruption. As oceans warm, L majuscula will bloom more frequently; therefore, public awareness of L majuscula and seaweed dermatitis in oceanside communities can help promote precautions that can reduce the risk for exposure. This article describes the irritants that lead to dermatitis, clinical presentation, and prevention and management of seaweed dermatitis.

Assessing the status of Ichkeul Lake and its catchment through identifying potentially toxic cyanobacteria, simultaneously extracted metals and use of acid-volatile-sulfide model

Lake Ichkeul is considered one of the most significant wetlands in the Mediterranean basin. It serves as a crucial wintering area for numerous western Palearctic birds. A notable decline in species diversity has been observed in the past decade, attributed to excessive water usage for irrigation and the effects of climate change. This study aimed to assess the status of Ichkeul Lake and its catchment through identifying potentially toxic cyanobacteria, and sediment quality. Our first striking finding was that Lyngbya majuscula the dominant potentially toxic cyanobacterium in the lake originated from the Tinja channel. Trace element concentrations in lake sediments exceeded SQG standards which is indicative of rare detrimental effects to biological life. However, the sediment in front of the Tinja channel exhibited high contamination levels of Zn and Cd. These findings call for an urgent need to ensure the ongoing management and conservation of this world heritage site.

Green synthesis of manganese dioxide nanoparticles: photocatalytic and antimicrobial investigations

ABSTRACT In the present study, we report the green synthesis of manganese dioxide (MnO2) nanoparticles using Lyngbya Majuscula by the single-step co-precipitation method. The green synthesised MnO2 nanoparticles were characterised by a mix of microscopy, and spectroscopic methods such as X-Ray diffraction analysis, Fourier transform infrared Spectroscopy, Field emission scanning electron microscope, and High-Resolution Transmission Electron Microscopy, analysis. The photocatalytic degradation ability of the as-prepared sample was investigated against the methylene blue (MB) dye under different light sources such as LED, UV, and sunlight irradiation. According to the photocatalytic degradation analysis, the green synthesised MnO2 nanoparticles show high photocatalytic degradation under UV light irradiation. Similarly, the antibacterial activity of the green synthesised MnO2 nanoparticles are investigated against the Trichodermaviride, Micrococcus Luteus, Staphylococcus Aureus, Aspergillus Niger, and Pseudomonas Aeruginosa. Furthermore, the green synthesised MnO2 nanoparticles show high efficacy of the agar well diffusion method in eradicating dangerous microorganisms.

Antibacterial assay of cyanobacteria in invitro conditions and its valuable applications

Cyanobacteria are aquatic and photosynthetic they survive in fresh water ponds and sewage water. Since these cyanobacteria are quite small and unicellular, they often grow in large colonies more enough to see by naked eye. Cyanobacteria they produce bluish green colour pigments as they are phycocyanin, phycobiliproteins and carotenoids. It may surprise you to know that cyanobacteria are still around they are one of the largest and most important groups of bacteria on earth. The cyanobacterial ethanolic extracts of Oscillatoria formosa, Oscillatoria subbrevis, Oscillatoria princeps, Oscillatoria sancta and Oscillatoria fischeri showed effective antibacterial activity against pathogenic microorganisms like Streptococcus pyogenes, Streptococcus pneumoniae, Clostridium perfringes, Salmonella typhi and Vibrio cholerae. Cyanobacteria like Oscillatoria curviceps, Lyngbya majuscula and Spirulina subsalsa are rich source of bioactive compounds with antibacterial, antifungal, antialgal and antiviral properties. Some cyanobacteria like Synechococcus elongatus have ability to accumulate polyhydroxyalkanoates which may be used as bioplastics. In addition to these applications the Cyanobacteria are also useful in agricultural practices like Nostoc commune and Anabaena aequalis as biofertilizers. Some eukaryotic green algae like Chlorella vulgaris, Botryococcus braunii and Schizochytrium limacinum produce more oil content for ecofriendly production of more biodiesel.

Kalkitoxin attenuates calcification of vascular smooth muscle cells via RUNX-2 signaling pathways.

Kalkitoxin (KT) is an active lipopeptide isolated from the cyanobacterium Lyngbya majuscula found in the bed of the coral reef. Although KT suppresses cell division and inflammation, KT's mechanism of action in vascular smooth muscle cells (VSMCs) is unidentified. Therefore, our main aim was to investigate the impact of KT on vascular calcification for the treatment of cardiovascular disease. Using diverse calcification media, we studied the effect of KT on VSMC calcification and the underlying mechanism of this effect. VSMC was isolated from the 6 weeks ICR mice. Then VSMCs were treated with different concentrations of KT to check the cell viability. Alizarin red and von Kossa staining were carried out to examine the calcium deposition on VSMC. Thoracic aorta of 6 weeks mice were taken and treated with different concentrations of KT, and H and E staining was performed. Real-time polymerase chain reaction and western blot were performed to examine KT's effect on VSMC mineralization. Calcium deposition on VSMC was examined with a calcium deposition quantification kit. Calcium deposition, Alizarin red, and von Kossa staining revealed that KT reduced inorganic phosphate-induced calcification phenotypes. KT also reduced Ca++-induced calcification by inhibiting genes that regulate osteoblast differentiation, such as runt-related transcription factor 2 (RUNX-2), SMAD family member 4, osterix, collagen 1α, and osteopontin. Also, KT repressed Ca2+-induced bone morphogenetic protein 2, RUNX-2, collagen 1α, osteoprotegerin, and smooth muscle actin protein expression. Likewise, Alizarin red and von Kossa staining showed that KT markedly decreased the calcification of ex vivo ring formation in the mouse thoracic aorta. This experiment demonstrated that KT decreases vascular calcification and may be developed as a new therapeutic treatment for vascular calcification and arteriosclerosis.

Large bilateral corneal ulcers caused by debromoaplysiatoxin from the blue-green alga Lyngbya majuscula in a fisherman.

Toxic seaweed dermatitis is caused by toxins of the marine cyanobacterium Lyngbya majuscula after sea bathing in some tropical area. This rarely described irritant dermatitis results in papular and bullous lesions, mainly in the genital area but severe ocular lesions can occur.

Sea lice Lepeophtheirus spinifer, Tuxophorus sp. and Caligus sp. infections on wild-caught queenfish Scomberoides commersonnianus from northern Australia.

Studies of ectoparasites of wild-caught queenfish Scomberoides commersonnianus from several areas in northern Australia were reviewed to investigate relationships between parasite burdens, environmental conditions and external lesions. A sample of 27 queenfish captured near a dredge spoil disposal site in Gladstone Harbour, Queensland, Australia, in January 2012 was anomalous, with a high percentage of fish (66.6%) exhibiting grossly visible skin lesions including foci of erythema and petechial haemorrhages, particularly on the pectoral girdle and ventrolateral surfaces. Microscopically, lesions comprised acute epidermal erosion, ulceration and/or perivascular dermatitis with dermal oedema and depigmentation. Skin lesions were associated with high prevalence (100%) and intensity (mean = 21.2 copepods fish-1, range 4-46) of infection by sea lice Lepeophtheirus spinifer. Only queenfish infected with >10 L. spinifer presented with skin lesions. This is the first record of L. spinifer from Australia. In contrast, grossly visible skin lesions were not reported from queenfish (n = 152) sampled from other sites in the Northern Territory and Queensland, where the sampled fish had a much lower prevalence (51.3%) and intensity (mean = 3.54, range 0-26) of copepod (L. spinifer, Caligus spp. and Tuxophorus sp.) infections. Copepods from queenfish in studies undertaken outside Gladstone Harbour exhibited an over-dispersed pattern of infection, with the vast majority (n = 137, or 90.1%) of fish infected with <5 copepods. These data demonstrate that heavy L. spinifer infections, combined with poor water quality and/or direct exposure to contaminated dredge spoil and blooms of the cyanobacterium Lyngbya majuscula, can be associated with cutaneous disease in wild-caught queenfish.

Aplysiadione and aplysiaenal: Truncated biosynthetic intermediates of aplysiatoxins from a cyanobacterium

Aplysiatoxin and its derivatives have been isolated from marine cyanobacteria. The biosynthesis of their characteristic bicyclic skeletons from a linear polyketide intermediate has been proposed. Two polyketides, aplysiadione (1) and aplysiaenal (2), were isolated from the marine cyanobacterium Moorea producens (formerly Lyngbya majuscula) collected in the Okinawan coastal area. The polyketide chemical structures were elucidated from HR ESI-MS and NMR spectra. Aplysiadione (1) corresponds to a decarboxylated analog of the proposed biosynthetic intermediate of aplysiatoxins. Aplysiaenal (2) is a truncated analog of the linear intermediate. The isolation of aplysiadione (1) strongly supports the proposed ring formation mechanisms for the aplysiatoxins, and this compound is a rare example of a biosynthetic intermediate of polyketide secondary metabolites from marine cyanobacteria.

Synthesis of Silver Nanoparticles Using Lyngbya Majuscula Extract and their Antibacterial Effects

Synthesis of Silver Nanoparticles Using Lyngbya Majuscula Extract and their Antibacterial Effects

Assessment of the Chemical Diversity and Potential Toxicity of Benthic Cyanobacterial Blooms in the Lagoon of Moorea Island (French Polynesia)

In the last decades, an apparent increase in the frequency of benthic cyanobacterial blooms has occurred in coral reefs and tropical lagoons, possibly in part because of global change and anthropogenic activities. In the frame of the survey of marine benthic cyanobacteria proliferating in the lagoon of Moorea Island (French Polynesia), 15 blooms were collected, mainly involving three species—Anabaena sp.1, Lyngbya majuscula and Hydrocoleum majus-B. Their chemical fingerprints, obtained through high performance liquid chromatography combined with UV detection and mass spectrometry (HPLC-UV-MS) analyses, revealed a high extent of species-specificity. The chemical profile of Anabaena sp.1 was characterized by three major cyclic lipopeptides of the laxaphycin family, whereas the one of L. majuscula was characterized by a complex mixture including tiahuramides, trungapeptins and serinol-derived malyngamides. Toxicity screening analyses conducted on these cyanobacterial samples using Artemia salina and mouse neuroblastoma cell-based (CBA-N2a) cytotoxic assays failed to show any toxicity to a degree that would merit risk assessment with regard to public health. However, the apparently increasing presence of blooms of Lyngbya, Hydrocoleum, Anabaena or other benthic cyanobacteria on coral reefs in French Polynesia encourages the implementation of ad hoc monitoring programs for the surveillance of their proliferation and potential assessment of associated hazards.

Evaluation of antioxidant and neuroprotective activities of Lyngbya majuscula on human neural tissues

The neurodegenerative disease accounts for the functional dysfunction of the neural cells and is also caused by the oxidative stress that prevailed within the neural cells. The prophylactic activity of Cyanobacteria can inhibit the action of reactive oxygen species and can also act as a neuroprotective agent. In this current study, the antioxidant activity and neuroprotective effects of hydroalcoholic extract of Lyngbya majuscula against human neural PC12 cell line are evaluated using DPPH assay and MTT assay. Cell morphology of treated PC12 cells is observed by DAPI staining and DNA fragmentation and caspase enzyme activity are also conducted. The extract is found to possess preliminary phytochemicals such as alkaloids, flavonoids, steroids, terpenoids, anthroquinone, phenols, saponins and tannins. The results of this study indicate that L. majuscula extract has excellent free radical scavenging activity. MTT assay revealed that IC50 values are 406.45 ± 3.2 μg/mL and 426.14 ± 1.7 μg/Ml. The stimulation apoptosis by the extract is confirmed through DNA fragmentation analysis and it also possesses significant Caspase enzyme activity. The results evidence the potential neuroprotective effects of L. majuscula extract on PC12 cell lines. Further investigation will be required for the molecular mechanism and gene regulation.

Near-future ocean warming and acidification alter foraging behaviour, locomotion, and metabolic rate in a keystone marine mollusc

Environmentally-induced changes in fitness are mediated by direct effects on physiology and behaviour, which are tightly linked. We investigated how predicted ocean warming (OW) and acidification (OA) affect key ecological behaviours (locomotion speed and foraging success) and metabolic rate of a keystone marine mollusc, the sea hare Stylocheilus striatus, a specialist grazer of the toxic cyanobacterium Lyngbya majuscula. We acclimated sea hares to OW and/or OA across three developmental stages (metamorphic, juvenile, and adult) or as adults only, and compare these to sea hares maintained under current-day conditions. Generally, locomotion speed and time to locate food were reduced ~1.5- to 2-fold when the stressors (OW or OA) were experienced in isolation, but reduced ~3-fold when combined. Decision-making was also severely altered, with correct foraging choice nearly 40% lower under combined stressors. Metabolic rate appeared to acclimate to the stressors in isolation, but was significantly elevated under combined stressors. Overall, sea hares that developed under OW and/or OA exhibited a less severe impact, indicating beneficial phenotypic plasticity. Reduced foraging success coupled with increased metabolic demands may impact fitness in this species and highlight potentially large ecological consequences under unabated OW and OA, namely in regulating toxic cyanobacteria blooms on coral reefs.

Benthic cyanobacteria on coral reefs of Moorea Island (French Polynesia): diversity response to habitat quality

The marine benthic cyanobacteria on coral reefs of Moorea Island (French Polynesia) show significant changes in species diversity in response to environmental impacts. To study these changes in cyanobacterial diversity, we examined pristine and degraded coral reefs by combining microscopy of morphological properties of the taxa with characterization of each by 16S rRNA gene sequences. A total of 30 cyanobacterial species have been recorded, of which 10 (33%) of them represent a new record for Moorea Island. The majority of morpho-species we identified could be distinguished by phylogenetic analyses of 61 sequences. Our survey results showed a sharp distinction in the composition of benthic cyanobacterial assemblages from healthy (high living coral cover) versus degraded habitats (low live coral cover due to anthropogenic activities). Finally, 21 bloom-forming species were identified, occurring mostly in environmentally impacted area (north coast). Blooms were dominated by three species: Anabaena sp.1, Hydrocoleum majus-B, Lyngbya majuscula. This study provides novel insights into the taxonomy of tropical benthic cyanobacteria as important environmental indicators and advocates the use of new bioevaluative tools for the management of coral reef environments.

Oscillatoxin I: A New Aplysiatoxin Derivative, from a Marine Cyanobacterium.

Cyanobacteria have been shown to produce a number of bioactive compounds, including toxins. Some bioactive compounds obtained from a marine cyanobacterium Moorea producens (formerly Lyngbya majuscula) have been recognized as drug leads; one of these compounds is aplysiatoxin. We have isolated various aplysiatoxin derivatives from a M. producens sample obtained from the Okinawan coastal area. The frozen sample was extracted with organic solvents. The ethyl acetate layer was obtained from the crude extracts via liquid–liquid partitioning, then separated by HPLC using a reversed-phase column. Finally, 1.1 mg of the compound was isolated. The chemical structure of the isolated compound was elucidated with spectroscopic methods, using HR-MS and 1D and 2D NMR techniques, and was revealed to be oscillatoxin I, a new member of the aplysiatoxin family. Oscillatoxin I showed cytotoxicity against the L1210 mouse lymphoma cell line and diatom growth-inhibition activity against the marine diatom Nitzschia amabilis.

Global phylogeography of toxic cyanobacteria Moorea producens reveals distinct genetic partitioning influenced by Proterozoic glacial cycles

Lyngbya majuscula is a marine filamentous cyanobacteria belonging to the family Oscillatoriaceae. Recent phylogenetic analyses of L. majuscula have reclassified a subset of this species into various genera such as Moorea, Okeania and Dapis. From the genus Moorea, Moorea producens is a toxic invasive cyanobacterium that produces bioactive secondary metabolites that can cause severe inflammation and blistering. Despite the global distribution of M. producens, little information is available on their origin, patterns of dispersal and population structure. In this study, the spatial population structure of M. producens was investigated using near-complete 16S rRNA sequences. Analysis of the global population of M. producens by Isolation by Distance and STRUCTURE revealed two significantly distinct cosmopolitan populations that were separated by a genetic break. Lineage-specific divergence estimates of 147 cyanobacterial taxa, based on a relaxed molecular clock indicated the first global emergence of M. producens during the Mesoarchean and a subsequent global recolonization during the Mesoproterozoic period. We conclude that the genetic discontinuity between both cosmopolitan populations is attributed to refugia associated with Proterozoic glacial cycles.

Highly Convergent Total Synthesis and Assignment of Absolute Configuration of Majusculamide D, a Potent and Selective Cytotoxic Metabolite from Moorea sp.

The total synthesis of majusculamide D (MJS-D) is described, a lipopentapeptide originally isolated from Lyngbya majuscula and reisolated from a Moorea sp. MJS-D possesses selective and potent cancer cell toxicity. A scalable and convergent strategy with a minimal number of purifications produced significant quantities of MJM-D for in vivo evaluations. The absolute configuration of the 1,3-dimethyl-octanamide motif was determined by synthesis of this fragment via ZACA chemistry.

Antillatoxin (ATX) Time–Resolved Absorption and Resonance FT–IR and Raman Biospectroscopy and Density Functional Theory (DFT) Investigation of Vibronic–Mode Coupling Structure

Antillatoxin (ATX) is a potent lipopeptide neurotoxin produced by the marine cyanobacterium Lyngbya majuscula. ATX activates voltage–gated sodium channels, which can cause cell depolarisation, NMDA–receptor over activity, excess calcium influx and neuronal necrosis. Parameters such as FT–IR and Raman vibrational wavelengths and intensities for single crystal Antillatoxin are calculated using density functional theory and were compared with empirical results. The investigation about vibrational spectrum of cycle dimers in crystal with carboxyl groups from each molecule of acid was shown that it leads to create Hydrogen bonds for adjacent molecules. The current study aimed to investigate the possibility of simulating the empirical values. Analysis of vibrational spectrum of Antillatoxin is performed based on theoretical simulation and FT–IR empirical spectrum and Raman empirical spectrum using density functional theory in levels of HF/6–31G*, HF/6–31++G**, MP2/6–31G, MP2/6–31++G**, BLYP/6–31G, BLYP/6–31++G**, B3LYP/6–31G and B3LYP6–31–HEG**. Vibration modes of methylene, carboxyl acid and phenyl cycle are separately investigated. The obtained values confirm high accuracy and validity of results obtained from calculations.

Epiphytism differences in the commercial species of Gracilaria, G. fisheri, G. tenuistipitata, and G. salicornia, from Thailand

Epiphytism is a common phenomenon in seaweeds that can be observed in natural populations and under culture conditions. Epiphytes are generally attached superficially to the surface of the host. Some epiphytic species can penetrate into the tissue of the host, affecting its growth and productivity. This study was done to examine epiphytism in three Gracilaria species: G. fisheri, G. salicornia, and G. tenuistipitata. Sampling of natural and cultured populations was conducted at seven sites. The samples were examined using a light microscope (LM) and scanning electron microscope (SEM). In this study, the epiphytic algae found were mainly cyanobacteria (Lyngbya), Chlorophyceae (Cladophora and Ulva), Phaeophyceae (Padina), and Rhodophyceae (Ceramium, Hypnea, and Polysiphonia). Lyngbya majuscula had the highest density in G. fisheri (14.56 epiphytes cm−2; 40% host−1). A high density of Polysiphonia scopulorum (1.16 epiphytes cm−2; 30% host−1) was found on the G. fisheri plants. In addition, Cladophora species were found on all the Gracilaria species, particularly on G. salicornia plants (4.04 epiphytes cm−2; 43.33% host−1). G. salicornia plants were frequently dominated by Hypnea hamulosa (2.94 epiphytes cm−2; 40% host−1). In contrast, a small number of epiphytes were found on G. tenuistipitata compared with the other two species. The SEM micrographs revealed epiphytic attachment to the host and the extent that epiphytes penetrated the host tissues. Our study showed that G. fisheri and G. salicornia had a greater degree of susceptibility to epiphytes than G. tenuistipitata.

Cyanobacteria as Nanogold Factories: Chemical and Anti-Myocardial Infarction Properties of Gold Nanoparticles Synthesized by Lyngbya majuscula

To the best of our knowledge, cyanobacterial strains from the Arabian Gulf have never been investigated with respect to their potential for nanoparticle production. Lyngbya majuscula was isolated from the AlOqair area, Al-Ahsa Government, Eastern Province, Kingdom of Saudi Arabia. The cyanobacterium was initially incubated with 1500 mg/mL of HAuCl4 for two days. The blue-green strain turned purple, which indicated the intracellular formation of gold nanoparticles. Prolonged incubation for over two months triggered the extracellular production of nanogold particles. UV-visible spectroscopy measurements indicated the presence of a resonance plasmon band at ~535 nm, whereas electron microscopy scanning indicated the presence of gold nanoparticles with an average diameter of 41.7 ± 0.2 nm. The antioxidant and anti-myocardial infarction activities of the cyanobacterial extract, the gold nanoparticle solution, and a combination of both were investigated in animal models. Isoproterenol (100 mg/kg, SC (sub cutaneous)) was injected into experimental rats for three days to induce a state of myocardial infarction; then the animals were given cyanobacterial extract (200 mg/kg/day, IP (intra peritoneal)), gold nanoparticles (200 mg/kg/day, IP), ora mixture of both for 14 days. Cardiac biomarkers, electrocardiogram (ECG), blood pressure, and antioxidant enzymes were determined as indicators of myocardial infarction. The results showed that isoproterenol elevates ST and QT segments and increases heart rate and serum activities of creatine phosphokinase (CPK), creatine kinase-myocardial bound (CP-MB), and cardiac troponin T (cTnT). It also reduces heart tissue content of glutathione peroxidase (GRx) and superoxide dismutase (SOD), and the arterial pressure indices of systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP). Gold nanoparticles alone or in combination with cyanobacterial extract produced an inhibitory effect on isoproterenol-induced changes in serum cardiac injury markers, ECG, arterial pressure indices, and antioxidant capabilities of the heart.

Modeling Analysis of Potential Target of Dolastatin 16 by Computational Virtual Screening.

Dolastatin 16 is a cyclic depsipeptide isolated from the marine invertebrates and cyanobacterium Lyngbya majuscula, however, its bioactivity has been a historical question. In this study, peptidyl-prolyl cis-trans isomerase FKBP1A (FKBP12) was predicted as a potential target of dolastatin 16 via PharmMapper as well as verified using chemical-protein interactome (CPI) and molecular docking. FKBP1A has been previously identified as a target for the natural polyketide FK506 (tacrolimus), an immune suppressor inhibiting the rejection of organ transplantation in clinical use. The comparison study via the reverse pharmacophore screening and molecular docking of dolastatin 16 and FK506 indicated the good consistency of analysis with the computational approach. As the results, the lowest binding energy of dolastatin 16-FKBP1A complex was -7.4 kcal/mol and FK506-FKBP1A complex was -8.7 kcal/mol. The ligand dolastatin 16 formed three hydrogen bonds vs. four of FK506, as well as seven hydrophobic interactions vs. six of FK506 within the active site residues. These functional residues are highly repetitive and consistent with previously reported active site of model of FK506-FKBP1A complex, and the pharmacophore model was shown feasibly matching with the molecular feature of dolastatin 16.