Showing papers on "Lyngbya majuscula published in 2011"
TL;DR: The genome of Lyngbya majuscula 3L, a Caribbean strain that produces the tubulin polymerization inhibitor curacin A and the molluscicide barbamide, was sequenced using a combination of Sanger and 454 sequencing approaches and revealed a complex gene regulatory network, indicating an enhanced ability for environmental adaptation or microbial associations.
Abstract: Filamentous cyanobacteria of the genus Lyngbya are important contributors to coral reef ecosystems, occasionally forming dominant cover and impacting the health of many other co-occurring organisms. Moreover, they are extraordinarily rich sources of bioactive secondary metabolites, with 35% of all reported cyanobacterial natural products deriving from this single pantropical genus. However, the true natural product potential and life strategies of Lyngbya strains are poorly understood because of phylogenetic ambiguity, lack of genomic information, and their close associations with heterotrophic bacteria and other cyanobacteria. To gauge the natural product potential of Lyngbya and gain insights into potential microbial interactions, we sequenced the genome of Lyngbya majuscula 3L, a Caribbean strain that produces the tubulin polymerization inhibitor curacin A and the molluscicide barbamide, using a combination of Sanger and 454 sequencing approaches. Whereas ∼293,000 nucleotides of the draft genome are putatively dedicated to secondary metabolism, this is far too few to encode a large suite of Lyngbya metabolites, suggesting Lyngbya metabolites are strain specific and may be useful in species delineation. Our analysis revealed a complex gene regulatory network, including a large number of sigma factors and other regulatory proteins, indicating an enhanced ability for environmental adaptation or microbial associations. Although Lyngbya species are reported to fix nitrogen, nitrogenase genes were not found in the genome or by PCR of genomic DNA. Subsequent growth experiments confirmed that L. majuscula 3L is unable to fix atmospheric nitrogen. These unanticipated life history characteristics challenge current views of the genus Lyngbya.
105 citations
TL;DR: Lagunamide C exhibited weak anti-swarming activity when tested at 100 ppm against the Gram-negative bacterial strain, Pseudomonas aeruginosa PA01, and displayed significant antimalarial activity with IC(50) value of 0.29 μM when tested against Plasmodium falciparum.
92 citations
TL;DR: The identified analogues showed weaker cytotoxic activities compared to the two major parent compounds, pitipeptolides A and B, against HT-29 colon adenocarcinoma and MCF7 breast cancer cells and the latter finding suggests that the structure of pitipePTolides could be optimized for selective antibacterial activity.
67 citations
TL;DR: Pitiprolamide showed weak cytotoxic activity against HCT116 colon and MCF7 breast cancer cell lines, as well as weak antibacterial activities against Mycobacterium tuberculosis and Bacillus cereus.
Abstract: An unusual cyclic depsipeptide, pitiprolamide (1), was isolated from the marine cyanobacterium Lyngbya majuscula collected at Piti Bomb Holes, Guam. The structure was deduced using NMR, MS, X-ray crystallography, and enantioselective HPLC-MS techniques. Remarkably, proline represents half of the residues forming pitiprolamide (1). Other distinctive features include a 4-phenylvaline (dolaphenvaline, Dpv) moiety initially found in dolastatin 16 and the rare 2,2-dimethyl-3-hydroxyhexanoic acid (Dmhha) unit condensed in a unique sequence in one single molecule. Pitiprolamide (1) showed weak cytotoxic activity against HCT116 colon and MCF7 breast cancer cell lines, as well as weak antibacterial activities against Mycobacterium tuberculosis and Bacillus cereus.
54 citations
TL;DR: Compounds 1-3 showed weak cytotoxicity against MCF7 breast cancer and HT-29 colon cancer cells.
Abstract: Malyngamide 3 (1) and cocosamides A (2) and B (3) were isolated from the lipophilic extract of a collection of Lyngbya majuscula from Cocos Lagoon, Guam. The planar structures of compounds 1-3 were determined by spectroscopic methods. The absolute configuration of 1 was determined by modified Mosher's method, NOESY data, and comparison with lyngbic acid (4). The absolute configurations of 2 and 3 were assigned by enantioselective HPLC analysis and comparison with the closely related compound pitipeptolide A (5). Compounds 1-3 showed weak cytotoxicity against MCF7 breast cancer and HT-29 colon cancer cells.
50 citations
TL;DR: Serinolamide A exhibited a moderate agonist effect and selectivity for the CB1 cannabinoid receptor and represents the newest addition to the known cannabinomimetic natural products of marine origin.
Abstract: NMR-guided fractionation of two independent collections of the marine cyanobacteria Lyngbya majuscula obtained from Papua New Guinea and Oscillatoria sp. collected in Panama led to the isolation of the new lipids serinolamide A (3) and propenediester (4). Their structures were determined by NMR and MS data analysis. Serinolamide A (3) exhibited a moderate agonist effect and selectivity for the CB1 cannabinoid receptor (Ki = 1.3 μM, >5-fold) and represents the newest addition to the known cannabinomimetic natural products of marine origin.
36 citations
TL;DR: In this paper, two cyanobacteria Lyngbya majuscula and Spirulina subsalsa were used as bioreagent for the green synthesis of gold nanoparticles.
Abstract: Two cyanobacteria Lyngbya majuscula and Spirulina subsalsa were used as bioreagent for the green synthesis of gold nanoparticles. Within 72 h of incubation at 15 mg L-1 Au3+ solution, the cyanobacterial biomass turned purple indicating intracellular reduction of Au3+ to Au0 and subsequent formation of gold nanoparticles. Gold nanoparticles were extracted from the gold-loaded biomass using 7.5 mM sodium citrate solution and characterization was done by UVvisible spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR). While Spirulina showed synthesis of spherical nanoparticles of 5 nm -30 nm diameter along with very few nanorods, Lyngbya showed presence of spherical and hexagonal nanoparticles of 2 nm -25 nm diameters. XRD study confirmed the reduction of Au3+ to Au0. FTIR analysis indicated the presence of protein shells around the gold nanoparticles.
31 citations
TL;DR: Grassypeptolides F and G, bis-thiazoline-containing cyclic depsipeptides with a rare β-amino acid, extensive N-methylation, and a large number of d-aminos acids, are reported from an extract of the Palauan cyanobacterium Lyngbya majuscula.
Abstract: Grassypeptolides F (1) and G (2), bis-thiazoline-containing cyclic depsipeptides with a rare β-amino acid, extensive N-methylation, and a large number of D-amino acids, are reported from an extract of the Palauan cyanobac- terium Lyngbya majuscula. Both 1 and 2 were found to have moderate inhibitory activityagainstthetranscriptionfactorAP-1(IC50=5.2and6.0 μM,respectively).
22 citations
TL;DR: Recovery of accumulated Pb from the immobilized biomass suggests that repeated absorption-desorption is possible and lead accumulation by free and immobilized cyanobacteria, Lyngbya majuscula and Spirulina subsalsa was studied.
21 citations
TL;DR: Although both new compounds (1,2) showed potent brine shrimp toxicity, only guineamide G displayed significant cytotoxicity to a mouse neuroblastoma cell line with LC(50) values of 2.7 micrometer.
Abstract: Two new cyclic depsipeptides wewakamide A (1) and guineamide G (2) have been isolated from the marine cyanobacterium Lyngbya semiplena and Lyngbya majuscula, respectively, collected from Papua New Guinea. The amino and hydroxy acid partial structures of wewakamide A and guineamide G were elucidated through extensive spectroscopic techniques, including HR-FABMS, 1D (1)H and (13)C NMR, as well as 2D COSY, HSQC, HSQCTOCSY, and HMBC spectra. The sequence of the residues of wewakamide A was determined through a combination of ESI-MS/MS, HMBC, and ROESY. Wewakamide A possesses a β-amino acid, 3-amino-2-methylbutanoic acid (Maba) residue, which has only been previously identified in two natural products, guineamide B (3) and dolastatin D (4). Although both new compounds (1,2) showed potent brine shrimp toxicity, only guineamide G displayed significant cytotoxicity to a mouse neuroblastoma cell line with LC(50) values of 2.7 micrometer.
19 citations
TL;DR: The ability of the hermitamides to displace [(3)H]-BTX at 10 μM more potently than phenytoin, a clinically used sodium channel blocker, and electrophysiology showing that these compounds are potent blockers of the hNav1.2 voltage-gated sodium channel.
TL;DR: The stereoselective synthesis of the N-(Boc)2-protected peptide moiety of the jamaicamides is reported by utilizing Meldrum’s acid starting from l -alanine and N-Boc-β-alanine.
TL;DR: Gut analyses showed that bentho-planktivorous fishes exposed to L. majuscula in captivity had consumed a significantly greater quantity of prey by both total number and volume than fish exposed to sand treatments, suggesting that L. majesty blooms increase rates of prey encounter and consumption.
Abstract: Increasing concerns about the ecological impacts of ongoing and possibly worsening blooms of the toxic, carcinogenic cyanobacteria Lyngbya majuscula in Moreton Bay, Australia, led us to assess differences in meiofaunal prey assemblages between bloom and non-bloom substrates and the potential dietary impacts of dense L. majuscula blooms on the omnivorous benthivore, the Eastern Long-finned Goby, Favonigobius lentiginosus and the obligate meiobenthivorous juveniles of Trumpeter Whiting, Sillago maculata. Marked differences in invertebrate communities were found between sandy and L. majuscula bloom foraging substrates, with copepods significantly more abundant (18.49% vs. 70.44% numerical abundance) and nematodes significantly less abundant (55.91% vs. 1.21% numerical abundance) within bloom material. Gut analyses showed that bentho-planktivorous fishes exposed to L. majuscula in captivity had consumed a significantly greater quantity of prey by both total number (P < 0.0019) and volume (P < 0.0006) than fish exposed to sand treatments. Thus, it is likely for such fishes that L. majuscula blooms increase rates of prey encounter and consumption, with consequent changes in trophic relationships through shifts in predator–prey interactions between small benthivorous fishes and their meiofaunal prey.
TL;DR: The organism was considerably revived after incubating the irradiated cells in mineral medium under florescent light and in the dark suggesting existence of photoreactivation and dark repair in this cyanobacterium, however more experiments are needed to establish the existence of Photore activation anddark repair mechanism in the studied cyanobacteria.
Abstract: Lyngbya majuscula is a dominant organism in the east coast of India forming characteristic mat in dried saline soils simultaneously exposed to solar radiation of the tropics. Studies on the growth response, changes in the spectral properties of the methanolic extract and protein profile of this estuarine sheathed cyanobacterium to UV-B revealed existence of effective adaptation mechanism to withstand prolonged UV-B radiation. Carotenoids along with MAAs of the organism was increased with increase in UV irradiation. Increase in thickness of the mucilaginous sheath layer as well as cellular carbohydrate content was observed upon exposure to prolonged UV-B dose. Induction of 21 and 33 kDa low molecular weight proteins, and a 99 kDa protein together with formation of distinct multilayered sheath embedding trichomes with granulated cells were the adaptive features of the organism to cope with UV-B stress. The organism was considerably revived after incubating the irradiated cells in mineral medium under florescent light and in the dark suggesting existence of photoreactivation and dark repair in this cyanobacterium. However more experiments are needed to establish the existence of photoreactivation and dark repair mechanism in the studied cyanobacterium.
TL;DR: The 2Z-isomer of malyngamide K has been isolated and characterized from a Papua New Guinea field collection of the cyanobacterium Lyngbya majuscula and the planar structure was deduced by 1D and 2D NMR spectroscopic and mass spectral data interpretation.
Journal Article•
TL;DR: In this paper, the potential effects of Lyngbya majuscula (cyanobacterium) blooms have on the benthic invertebrate diversity and shorebird foraging ecology at Roebuck Bay.
Abstract: Nutrient enrichment can significantly alter biodiversity, producing shifts in assemblages of primary producers and favouring, for example, cyanobacterium blooms. These variations in the assemblage of primary producers consequently affect the primary consumers that depend on them. However, the consequences of these blooms for higher trophic levels are still unclear. Roebuck Bay, in the west Kimberley region is one of the main non-breeding areas for migratory shorebirds in Australia. The bay is characterised by an extremely high diversity and biomass of benthic invertebrates, which places this tropical intertidal area among the richest mudflats in the world, and it is likely that this rich benthic fauna supports the shorebird populations. Recent studies in Roebuck Bay have detected nutrient enrichment, with increasing frequency of cyanobacteria blooms. Here we present the preliminary results of the potential effects that Lyngbya majuscula (cyanobacterium) blooms have on the benthic invertebrate diversity and shorebird foraging ecology at Roebuck Bay. A site where Lyngbya majuscula was present showed a significant diminution in the diversity of benthic invertebrates relative to areas without a bloom. Also, although there was no apparent Lyngbya-induced change in the main prey of Bar-tailed Godwits Limosa lapponica, there was a change in the foraging behaviour of godwits in the area affected by Lyngbya, which appears to relate to a shift in diet. Nevertheless, although we found a correlation between Lyngbya presence and shifts in invertebrate assemblages, further work is required to confirm our findings.
TL;DR: NMR-guided fractionation of a non-polar extract of a Florida Keys collection of Lyngbya sp.
TL;DR: The occurrence of benthic marine algae is examined in different parts of the central and southern Caribbean of Costa Rica, showing an occurrence of 17 genera distributed among 4 Chroococcales, 2 Nostocales, and 11 Oscillatoriales.
Abstract: Las cianobacterias comprenden un grupo de microorganismos del dominio Bacteria (Woese et al. 1990) poco estudiado en Costa Rica. Los escasos trabajos realizados abordan tematicas relacionadas con la ocurrencia de cianobacterias en plantas de tratamiento y la evaluacion de su potencial como indicadoras de contaminacion o la produccion de toxinas. En la presente investigacion se analizo la diversidad y distribucion de cianobacterias bentonicas marinas en diferentes puntos del Caribe central y sur de Costa Rica. Los resultados obtenidos muestran una ocurrencia de 17 generos taxonomicos, 4 de ellos pertenecen a Chroococcales (24%), 2 Nostocales (12%) y 11 Oscillatoriales (64%). Las poblaciones de cianobacterias se mantienen relativamente constantes a lo largo de los meses de escasa precipitacion cuando las aguas se mantienen calmas y claras, mientras que en la estacion lluviosa o cuando se presenta gran cantidad de sedimentos suspendidos y fuertes oleajes las poblaciones disminuyen en forma notable. Los generos Lyngbya, Phormidium, Oscillatoria, Spirulina y Leptolyngbya se encuentran distribuidos en practicamente todas las zonas muestreadas, sin embargo, el genero Lyngbya alcanza poblaciones muy importantes en los puntos de muestreo del Caribe central, en especial en Isla Uvita, donde es posible localizar un gran numero de colonias de Lyngbya majuscula y Lyngbya confervoides, especies que estan relacionadas con ambientes alterados por el ser humano.AbstractCyanobacteria constitute a group of microorganisms belonging to the Bacteria domain (Woese et al. 1990). Little has been studied about it in Costa Rica and those studies have addressed issues related to the occurrence of cyanobacteria in water treatment plants and the assessment of their potential as toxin production or pollution indicators. In the present paper the occurrence of benthic marine algae is examined in different parts of the central and southern Caribbean of Costa Rica. The results show an occurrence of 17 genera distributed among 4 Chroococcales (24%), 2 Nostocales (12%), and 11 Oscillatoriales (64%). Cyanobacteria populations remain relatively constant throughout the months of limited rainfall when the waters remain calm and clear, while in the rainy season or when there is a large amount of suspended sediments and heavy swells populations decline significantly. The genera Lyngbya, Phormidium, Oscillatoria, Spirulina and Leptolyngbya are distributed in virtually all areas sampled; however the genus Lyngbya reaches important populations in the sampling points of the central Caribbean, especially near Uvita Island where they can be found in large numbers of colonies Lyngbya majuscula and Lyngbya confervoides, species that are related to environments altered by human activity.