Scytonema Ocellatum Research Articles

Cyanobacteria Scytonema javanicum and Scytonema ocellatum Lipopolysaccharides Elicit Release of Superoxide Anion, Matrix-Metalloproteinase-9, Cytokines and Chemokines by Rat Microglia In Vitro.

Cosmopolitan Gram-negative cyanobacteria may affect human and animal health by contaminating terrestrial, marine and freshwater environments with toxins, such as lipopolysaccharide (LPS). The cyanobacterial genus Scytonema (S) produces several toxins, but to our knowledge the bioactivity of genus Scytonema LPS has not been investigated. We recently reported that cyanobacterium Oscillatoria sp. LPS elicited classical and alternative activation of rat microglia in vitro. Thus, we hypothesized that treatment of brain microglia in vitro with either cyanobacteria S. javanicum or S. ocellatum LPS might stimulate classical and alternative activation with concomitant release of superoxide anion (O2−), matrix metalloproteinase-9 (MMP-9), cytokines and chemokines. Microglia were isolated from neonatal rats and treated in vitro with either S. javanicum LPS, S. ocellatum LPS, or E. coli LPS (positive control), in a concentration-dependent manner, for 18 h at 35.9 °C. We observed that treatment of microglia with either E. coli LPS, S. javanicum or S. ocellatum LPS generated statistically significant and concentration-dependent O2−, MMP-9 and pro-inflammatory cytokines IL-6 and TNF-α, pro-inflammatory chemokines MIP-2/CXCL-2, CINC-1/CXCL-1 and MIP-1α/CCL3, and the anti-inflammatory cytokine IL-10. Thus, our results provide experimental support for our working hypothesis because both S. javanicum and S. ocellatum LPS elicited classical and alternative activation of microglia and concomitant release of O2−, MMP-9, cytokines and chemokines in a concentration-dependent manner in vitro. To our knowledge this is the first report on the toxicity of cyanobacteria S. javanicum and S. ocellatum LPS to microglia, an immune cell type involved in neuroinflammation and neurotoxicity in the central nervous system.

Soil Algae of El-Farafra Oasis (The Western Desert, Egypt), and N2-fixation Efficiency of Five Heterocytous Cyanophytes

IN TOTAL 47 soil algal morphospecies were cultured and identified from the desert soils of El-Farafra Oasis, The Western Desert (Egypt). The most of them were related to Cyanophyta (34 algal taxa), followed by Chlorophyta and Xanthophyta (5 algal taxa belonging to each). Bacillariophyta represented only by 3 species. Moreover, this work enriched the Egyptian soil algal flora with 5 different algal taxa: Westiellopsis prolifica Janet, Cylindrospermum gregarium (Zakrz.), Cylindrospermum. licheniforme (Bory) Kutz., Chlorocloster caudatus Pasch. and Tetraktis aktinastroides Pasch. Furthermore, the potentialities of atmospheric N2-fixation efficiency of Calothrix elenkinii Kossinsk., Nodularia harveyana f. sphaerocarpa (Born. et Flah.) Elenk., Scytonema ocellatum Lyngb., Stratonostoc linckia (Roth) Elenk. and Westiellopsis prolifica Janet were investigated. However, C. elenkinii, W. prolifica and S. ocellatum exhibited to a large extent the highest fixation rates with mean values of 18.89, 30.52 and 33.01 μmole ml-1 h-1, respectively, followed by S. linckia (16.71 μmole ml-1 h-1) and Nodularia harveyana f. sphaerocarpa (12.01 μmole ml-1 h-1). In conclusion, Scytonema ocellatum and Westiellopsis prolifica can used as promising eco-friendly natural bio-fertilizers for the sustainable development in the desert habitats.

A preliminary survey of the diversity of soil algae and cyanoprokaryotes on mafic and ultramafic substrates in South Africa

Despite a large body of work on the serpentine-substrate effect on vascular plants, little work has been undertaken to describe algal communities found on serpentine soils derived from peridotite and other ultramafic rocks. We report a preliminary study describing the occurrence of algae and cyanoprokaryotes on mafic and ultramafic substrates from South Africa. Results suggest that slope and aspect play a key role in species diversity and community composition and, although low pH, nutrients and metal content do not reduce species richness, these edaphic features also influence species composition. Further, typical soil genera such as Leptolyngbya, Microcoleus, Phormidium, Chlamydomonas, Chlorococcum and Hantzschia were found at most sites. Chroococcus sp., Scytonema ocellatum, Nostoc linckia, Chlorotetraedron sp., Hormotilopsis gelatinosa, Klebsormidium flaccidium, Pleurococcus sp. and Tetracystis elliptica were unique to one serpentine site. The preliminary survey provides directions for future research on the serpentine-substrate effect on algal and cyanoprokaryote diversity in South Africa.

Pilot survey of cyanobacterial diversity from the neighborhood of San Gerardo de Rivas, Costa Rica with a brief summary of current knowledge of terrestrial cyanobacteria in Central America

Costa Rica is considered to be a biodiversity hotspot but little is known of its cyanobacterial flora and only a few studies dealing with aeroterrestrial algae have been published from this region so far. Our work focuses on the diversity of terrestrial cyanobacteria from Costa Rican cloud forest and compares our findings to knowledge from surrounding regions. In March 2010 samples of macroscopic cyanobacterial mats were collected from rocks, soils and a bromeliad leaf pool near the town of San Gerardo de Rivas, Costa Rica. The composition of the mats was investigated using light microscopy of fresh samples and acquired cultures. Among the 52 morphotypes revealed, heterocytous cyanobacteria with colored sheaths dominated, even though the most common species was Aphanocapsa cf. muscicola. The majority of morphotypes were determined to species level, and the rest was classified only to genus. Interestingly, nearly half of the species are considered to be cosmopolitan according to current knowledge and only four of the species present in our samples were known previously from Costa Rica (Stigonema minutum, Scytonema ocellatum, Sc. javanicum, and Sc. hofmannii). These results emphasize the need for phycological research in this understudied tropical area. We believe that our study will help not only to uncover further biodiversity in Costa Rican cloud forest but also to understand the distribution of cyanobacterial species among different biogeographical and climatic regions.

ChemInform Abstract: Isotactic Polymethoxy-1-alkenes from the Terrestrial Blue-Green Alga Scytonema ocellatum: Structure and Synthesis.

Abstract Novel isotactic polymethoxy-1-alkenes 2 – 5 were isolated from the tolytoxin-producing blue-green alga Scytonema ocellatum . The gross structures and relative configurations were determined by NMR and mass spectral analysis. Synthesis of optically active 2 – 4 in a stereocontrolled manner established their absolute configurations.

Exopolysaccharides of Two Cyanobacterial Strains from Roman Hypogea

The cytomorphology and the exopolysaccharides of two heterocystous cyanobacteria, Scytonema ocellatum CP8-2 and Fischerella maior NAV 10 bis, isolated from biofilms collected in two Roman hypogea, were investigated from a cytochemical, ultrastructural and biochemical point of view. Cytochemical stains and observation using light and transmission electron microscopy showed a bi-layered sheath in both cyanobacteria, with a different composition in sulphated and carboxylic groups. RP-HPLC of the extracted polysaccharides forming the mucous matrix showed the neutral sugars glucose and arabinose and the charged galacturonic acid as the main monosaccharides. Circular dichroism spectra recorded at varying pH and temperature showed that these polymers followed a random coil model and did not present a structured organised conformation at ambient temperature. The outcomes of this study increase the understanding of colonization and biodeterioration of important archaeological and cultural sites by cyanobacterial biofilms and the role of the exopolymeric substances involved.

Blue green algae in the biological soil crusts of different regions of India

AbstractBlue green algae (Cyanobacteria) occurring as biological soil crust intermingled with soil particles in the upper few millimeters of soil surfaces from different regions of India were studied. Sampling of crusts was done from four different soil types, i.e. laterite soils of the east coast, brown forest of soils of the east and central region, arid soils of the southern region and sandy soils of the west coast of India. One species each of the blue green algae Lyngbya arboricola, Scytonema ocellatum, Scytonema chiastum and Plectonema notatum as the dominant component in the four types of crust. Seve‐ ral other species of blue green algae belonging to genera Oscillatoria, Phormidium, Microcoleus, Nostoc, Aulosira, Calothrix, Hapalosiphon, Fischerella, Westiellopsis and Stigonema also appeared in the enrichment culture as minor components along with the dominant species. No other species of any other group of algae was a component of these crusts during the dry season. A total number of 48 species attributed to 15 different genera was encountered in different biological soil crusts of India. All these species are described with illustrations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Cryptobiotic cyanobacteria: an alternative in organic agriculture

Heterocystous filamentous cyanobacterium Scytonema cf. ocellatum strain SCL1097-22 was produced in a large outdoor photoreactor (2001 capacity). The cyanobacterial biomass was applied to soil used in growing the California variety of chili pepper (Capsicum annum). Chili peppers were grown under the following four conditions: untreated natural soil, addition of 30% organic substrate, addition of cyanobacteria, and addition of 30 % organic substrate with cyanobacteria. Treatment of soil only with Scytonema produced high a yield of chili pepper, averaging 1518 ± 96 g and lengths ranging from 12-15 cm. A microscopic study of the soil with this treatment showed living filaments of Scytonema, and the presence of a cyanobacterial community that included Leptolynghya, Oseillatoria, and Microcoleus. The treatment of soil enriched with 30% organic substrate and Scytonema yielded chili pepper averaging 1263 ± 46 g and lengths ranging from 12-17 cm. This soil showed only a few living filaments of Scytonema and the absence of a cyanobacterial community. Soil enriched with 30% organic substrate without Scytonema yielded chili pepper averaging 1004 ± 41 g and lengths ranging from 12-15 cm. Production in untreated natural soil yielded chili pepper averaging 925 ± 47 g and length averaging 10 cm. Statistical analyses of the length of pepper showed significant differences, with greater length resulting from treatments with Scytonema ocellatum strain SCL1097-22 than with no treatment. This cyanobacterial strain is proposed as an alternative source of nutrients in organic faming.

Cyanobacteria of inselbergs in the Atlantic rainforest zone of eastern Brazil

Inselbergs of the Atlantic rainforest zone in south-eastern Brazil typically appear black because of the presence of a dense cyanobacterial film. We investigated this autotrophic, microorganism covering on the exposed rock surfaces of five selected inselbergs along a latitudinal gradient, from Parati Mirim in the south to Serra dos Amores in the north. The biofilm was 0.1–0.5 mm thick and consisted mainly of cyanobacteria and rarely cyanobacterial lichens, together with a few filamentous deuteromycete fungi. The biofilm itself was stratified, consisting of three strata: (1) an endolithic stratum, with chasmolithic Chroococcidiopsis sp. and Gloeocapsa sanguinea; (2) an epilithic understorey layer with unicellular forms like G. sanguinea and Xenotholos kerneri; and (3) an upper epilithic layer, composed of filamentous cyanobacteria like Scytonema myochrous, S. ocellatum, Stigonema mamillosum and S. hormoides. In total, 16 species of cyanobacteria, belonging to eight different genera were found on exposed rock surfaces uninfluenced by higher vegetation. The unicellular forms G. sanguinea and X. kerneri and the filamentous cyanobacterium Scytonema ocellatum were the most frequent species. When compared with the cyanobacterial flora of inselbergs in Venezuela, French Guyana and Ivory Coast, the Brazilian inselbergs showed the greatest similarities to those of Venezuela.

Regulation of scytophycin accumulation in cultures of Scytonema ocellatum. II. Nutrient requirements.

The effects of optimal sources and concentrations of major nutrients (supplying N, S, P, K+, Na+, Ca2+, Mg2+, and inorganic carbon) and organic buffers on growth and secondary metabolite accumulation in Scytonema ocellatum strain FF-66-3 were determined. Nitrate, phosphate, magnesium, and sulfur had no specific stimulatory or inhibitory effects on scytophycin accumulation within the range of concentrations that supported optimal growth. Calcium concentrations greater than those required for growth (0.1 mM) stimulated scytophycin accumulation. Sodium carbonate concentrations in excess of 0.25 mM strongly inhibited growth. Ammonium (2.5 mM) inhibited both growth and product formation. 3-[N-Morpholino]propanesulfonic acid at 3-5 mM effectively controlled pH and facilitated both growth and product formation.

Synthesis and absolute configuration of an isotactic nonamethoxy-1-pentacosene from the blue-green alga Scytonema ocellatum

Synthesis of the novel isotactic nonamethoy-1-pentacosene ( 3) isolated from the terrestrial blue-green alga Scytonema ocellatum was accomplished in a stereocontrolled manner and the absolute configuration was established.

Regulation of scytophycin accumulation in cultures of Scytonema ocellatum. I. Physical factors

Scytonema ocellatum (Cyanobacteria or Cyanophyta) produces macrolide antibiotics of the scytophycin family that are antifungal, cytostatic agents and act by disrupting actin microfilaments. Scytophycin accumulation paralleled vegetative growth. Tolytoxin continued to accumulate throughout the growth cycle, whereas 6-hydroxy-7-O-methylscytophycin E (HMSE) and 19-O-demethylscytophycin C (DMSC) reached plateau levels prior to cessation of growth, suggesting a logical biosynthetic pathway of DMSC → ? → HMSE → tolytoxin. A rapid decrease in scytophycin content observed in newly inoculated cultures suggests that the scytophycins are continuously metabolized. The optimal temperature for production was 25°C. Continuous illumination at an intensity of at least 25 μml photons m−2 s−1 was required for maximum yield. Growth and metabolite production were optimal in the pH range of 8.0 to 8.5.

Isotactic polymethoxy-1-alkenes from the terrestrial blue-green alga [formula omitted]: Structure and synthesis

Novel isotactic polymethoxy-1-alkenes 2 – 5 were isolated from the tolytoxin-producing blue-green alga Scytonema ocellatum . The gross structures and relative configurations were determined by NMR and mass spectral analysis. Synthesis of optically active 2 – 4 in a stereocontrolled manner established their absolute configurations.

Tolytoxin and New Scytophycins from Three Species of Scytonema

Tolytoxin [1], the major cytotoxin associated with Scytonema mirabile strain BY-8-1, Scytonema burmanicum strain DO-4-1 and Scytonema ocellatum strains DD-8-1, FF-65-1, and FF-66-3, has been shown to be 6-hydroxy-7-O-methylscytophycin B. Minor amounts of three other new cytotoxic scytophycins, 6-hydroxyscytophycin B [2], 19-O-demethylscytophycin C [3], and 6-hydroxy-7-O-methylscytophycin E [4], have also been isolated from these cyanophytes. The gross structures and stereochemistry are based on nmr and cd analysis and on comparison with scytophycins A-E.