Species Of Scytonema Research Articles

Extraction and Native PAGE Separation of Phycobiliproteins from Some Cyanobacteria Collected from Their Natural Habitats

Phycobiliproteins are a group of coloured proteins present in cyanobacteria and algae. They can be divided into three types based on their absorption spectra. These are phycocyanin, phycoerythrin and allophycocyanin. These pigment proteins are used as potential natural colorant in chewing gums, candies, soft drinks, dairy products and cosmetics like lipstick and eyeliners. They are also extensively commercialized for fluorescent applications in clinical immunological analysis. The phycobiliproteins from cyanobacteria have also been reported to have ant-cancerous, anti-inflammatory and antioxidant properties. In view of the increasing demand of these fluorescent pigments, it becomes important to find new species of cyanobacteria and exploit them for their phycobiliprotein content. In present work some commonly available cyanobacteria were collected from their natural habitats and analysed for their phycobiliprotein content. The extraction of phycobiliprotein was done in phosphate buffer and quantitative analysis of the pigment components was done. The study showed that all the cyanobacteria are the potential source of phycocyanin whereas phycoerythrin is significantly present in species of Lyngbya and Oscillatoria. The phycobiliprotein components were separated on Native PAGE which can be partially purified by electroelution. The percentage loss of phycobiliprotein content in stored cyanobacterial biomass for two months showed that phycoerythrin was more stable in Lyngbya and Oscillatoria as compared to the phycocyanin. The species of Scytonema showed good amount of phycocyanin content whereas allophycocyanin was significantly present and was stable in Aulosira sp.

Geosmin-producing Scytonema foetidum sp. nov. (Scytonemataceae, Cyanobacteria): morphology and molecular phylogeny

A novel Scytonema species, Scytonema foetidum sp. nov. is described by combining morphological and genetic evidences. Two clonal strains of the new species were isolated from a wet soil sample taken from the Khek River in the lower northern part of Thailand. This species is morphologically similar to S. hofmanii, but can be differentiated by a small filament width, conically rounded apical cell, and sheath present throughout the whole trichome. The 16S ribosomal RNA (rRNA), rbcLX, and nifH phylogenetic trees indicated that S. foetidum clearly formed a unique cluster within the Scytonema sensu stricto clade and shared low 16S rRNA sequence similarity (<98.4%) with the phylogenetically related taxa, supporting separation at species level. The 16S-23S rRNA internal transcribed spacer (ITS) sequences of S. foetidum also possessed unique secondary structures in D1-D1', Box B, and V3 helices, differentiating this species from other known Scytonema species. Furthermore, S. foetidum could produce the odoriferous compound, geosmin.

Insights into the phylogeny of false-branching heterocytous cyanobacteria with the description of Scytonema pachmarhiense sp. nov. isolated from Pachmarhi Biosphere Reserve, India.

A false branching cyanobacterium (strain 10A1_PS) was isolated from a freshwater body of the Pachmarhi Biosphere Reserve, India and was characterised using the polyphasic approach. The detailed morphological examination indicated that the strain belonged to the complex genus Scytonema as it exhibited typical false branching character whose frequency increased with age of the culture. As the family Scytonemataceae and the genus Scytonema has been shown to be polyphyletic in many studies, we provide deep insights into the phylogenetic complexities within the family Scytonemataceae based on 16S rRNA gene phylogeny along with complete morphological, molecular and phylogenetic characterisation of the strain. The 16S rRNA gene phylogenetic tree inferred by Bayesian Inference, Neighbor-Joining and Maximum Parsimony methods showed that the strain clustered within the Scytonema sensu stricto clade. The phylogenetic distance and the positioning of the strain clearly indicated it to be different from other Scytonema species. Further analysis using rbcL phylogeny, folded secondary structures of the 16S-23S ITS, p-distance and percentage pairwise similarity matrix clearly distinguished the strain 10A1_PS from the other closely related species. In accordance with the International Code of Nomenclature for Algae, Fungi and Plants, we propose the name of the new species to be Scytonema pachmarhiense.

A new species of Scytonema isolated from Bilaspur, Chhattisgarh, India using the polyphasic approach

A false branching cyanobacterium (strain 1F-PS) isolated from a fresh water body of Bilaspur (Chhattisgarh, India) is described here as a new species of the polyphyletic genus Scytonema. Morphological, ecological, molecular and phylogenetic evidence validated the strain as a new species. Observations of the filaments in different phases of growth, different levels of microscopic studies, the presence of a textured thin sheath throughout the length of the trichome, differences in the shape and dimensions of the vegetative cells and heterocytes and ecological attributes show that the strain differed from the rest of the closely related species. Sequencing of the 16S rRNA gene resulted in 99% similarity with Scytonema bilaspurensis and 97.07% sequence similarity with Scytonema hofmannii PCC 7110, while rbcl and psbA sequences showed 99 and 97% similarities with S. bilaspurensis, respectively. Phylogenetic assessments indicated a large phylogenetic distance and separate clustering of the strain 1F-PS for all the molecular markers.

Phenotype diversity and phylogeny of selected Scytonema-species (Cyanoprokaryota) from SE Brazil.

Members of the genus Scytonema belong to prominent components of microflora of tropical and subtropical soils, but their diversity and taxonomic classification is still little known. Molecular analyses of isolated strains, but also the morphological and ecological examination of natural populations are important for the starting revisions. Here we present phenotype characteristics of fourteen morphotypes of the cyanobacterial genus Scytonema from the SE Brazil, mostly from the state Sao Paulo and from the Atlantic Rainforest (ecosystem of Mata Atlântica). The populations of studied Scytonema species are ecologically significant, as they hold the dominant position in the microvegetation communities of lateritic and forest soils and of stony substrates (less frequently also aquatic forms). Species commonly distributed throughout the tropical regions (such as S. guyanense, S. javanicum, S. stuposum), as well as the types with restricted geographic distribution in S America are included in the study. Two new species from a little known subgenus Myochrotes, in which the cultivation is difficult, are described: S. papillicapitatum Sant´Anna et Komarek and S. chorae Sant´Anna et Komarek. Our analyses support the principle of congruency of morphological characters with phylogenetic position of the studied species.

Characterization of cyanobacteria isolated from biofilms on stone monuments at Santiniketan, India

Cyanobacterial biofilms occurring on the exterior of three stone monuments at Santiniketan, India were analyzed. Species of Scytonema and Tolypothrix were the major components of these biofilms. Identification was obtained by morphometric procedures and 16S rRNA gene sequencing. Biofilms cultured for prolonged periods revealed the presence of several other cyanobacteria belonging to 14 different genera. Cyanobacteria on stone in the tropical environment of India formed a distinct cluster that was quite different from that of cyanobacteria reported for a similar substratum in temperate regions. Absorption spectra of the organisms from Santiniketan showed a high quantity of scytonemin, mycosporine-like amino acids, and carotenoids. All of the organisms survived in a desiccated state and rapidly revived after wetting. The organisms were heterocystous and nitrogenase activity was reactivated within 24 h of wetting by which time heterocysts in their filaments had also appeared.

Survey of Scytonema (Cyanobacteria) and associated saxitoxins in the littoral zone of recreational lakes in Canterbury, New Zealand

Smith F.M.J., Wood S.A., Wilks T., Kelly D., Broady P.A., Williamson W. and Gaw S. 2012. Survey of Scytonema (Cyanobacteria) and associated saxitoxins in the littoral zone of recreational lakes in Canterbury (New Zealand). Phycologia 51: 542–551. DOI: 10.2216/11-84.1The recent identification of saxitoxin-producing Scytonema cf. crispum triggered a survey of metaphyton and periphyton for Scytonema spp. in 34 high-use recreational lakes across Canterbury, New Zealand. Scytonema was observed in 10 of the lakes surveyed. Three morphospecies were identified: Scytonema cf. crispum, Scytonema cf. chiastum and Scytonema cf. fritschii. Environmental samples containing Scytonema were analysed for saxitoxins using the Jellett rapid test for paralytic shellfish poisoning, and saxitoxin variants were identified in positive samples using high-performance liquid chromatography with fluorescence detection (HPLC–FD). Cultures were established from selected sites and their phylogeny investigated using partial 16S rRNA gene sequences. These cultures were also screened for a region of sxtA, a gene involved in saxitoxin production. Cultures containing the sxtA gene were analysed for saxitoxins with HPLC–FD. Saxitoxins were only identified in cultures of S. cf. crispum and environmental samples containing this species. HPLC–FD analysis of these environmental samples and cultures identified saxitoxin and the variants gonyautoxins (GTX1–5), neosaxitoxin, decarbamoyl saxitoxin and decarbamoyl gonyautoxins (dcGTX2/3). This was the first report of these saxitoxin variants from cyanobacteria in New Zealand. All cultures of S. cf. crispum contained the sxtA gene segment. The partial 16S rRNA gene sequence of Scytonema C. Agardh ex Bornet & Flahault cultures were compared with cyanobacterial sequences from GenBank, only S. cf. fritschii clustered amongst other Scytonema species. The identification of metaphytic saxitoxin-producing S. cf. crispum highlighted a new freshwater habitat where toxic cyanobacteria may need to be monitored.

First report of saxitoxin production by a species of the freshwater benthic cyanobacterium, Scytonema Agardh

Saxitoxins or paralytic shellfish poisons (PSP) are neurotoxins produced by some species of freshwater cyanobacteria and marine dinoflagellates. Samples collected from the metaphyton of a drinking-water supply’s pre-treatment reservoir and a small eutrophic lake in New Zealand returned positive results when screened using a Jellett PSP Rapid Test Kit. The dominant species in the sample was identified as Scytonema cf. crispum. A non-axenic clonal culture (UCFS10) was isolated from the lake. The partial 16S rRNA gene sequence shared only a 91% or less sequence similarity with other Scytonema species, indicating that it is unlikely that this genus is monophyletic and that further in-depth phylogenetic re-evaluation is required. The sxtA gene, which is known to be involved in saxitoxin production, was detected in UCFS10. Saxitoxin concentrations were determined from the lake samples and from UCFS10 using pre-column oxidation high performance liquid chromatography with fluorescence detection. Saxitoxin was the only variant detected and this was found at concentrations of 65.6 μg g−1 dry weight in the lake sample and 119.4 μg g−1 dry weight or 1.3 pg cell−1 in UCFS10. This is the first confirmation of a saxitoxin-producing species in New Zealand and the first report of saxitoxin production by a species of Scytonema.

Growth response and protein profile of two different Scytonema species from cave walls and soil crusts in light and dark

Growth response and protein profile of two different Scytonema species from cave walls and soil crusts in light and dark

Diversity and characteristics of terrestrial cyanobacteria near gimhae city, Korea

Cyanobacteria samples were collected from smears and mats growing on the surfaces of buildings, roadside walls, rocks, and monuments near Gimhae City, Korea. These populations were not as thick and dense, nor as diverse, as those found in temperate and tropical regions. Crusts at Gimhae City were dominated by colonial forms of species fromChroococcus, Aphanothece,Aphanocapsa, Gloeofthece,Gloeocapsa, andChroococidiopsis, as well as by filamentous forms from species ofScytonema andTolypothrix. The colonial forms appeared primarily as smears, especially for species ofGloeocapsa andChroococcidiopsis, whereas filamentous forms were the major constituents of mat populations. Invariably, the cells and trichomes of these colonial and filamentous forms were enclosed with a thick, firm, multi-colored laminar sheath, as seen by transmission electron microscopy. Such an association between cell walls and trichomes was stronger in the colonial forms, particularly forGloeocapsa, compared with the filamentous forms, in which the sheath did not detach from the wall even under arid conditions. The organization of cytoplasmic structures, particularly the thylakoid membranes, was least affected by acute dryness.

Decastronema kotori gen. nov., comb. nov.: a mat-forming cyanobacterium on Cretaceous carbonate platforms and its modern counterparts

The fossil renamed here was first described in 1959 as Aeolisaccus kotori Radoicic, a new species of a problematic fossil worm, Aeolisaccus Elliott. In 1975 De Castro recognized the true identity of this microbial fossil: a cyanobacterium related closely to the modern genus Scytonema. The fossil is common in the sediments of the Mesozoic carbonate platforms of southern Europe. This contribution confirmed De Castro’s interpretation, determined, using the high resolution of the SEM, the extent to which these fossils have preserved their original architecture, and investigated their presumed modern counterparts among the abundant mat-forming species of Scytonema on the intertidal flats of Andros Island, a part of the Bahama carbonate platform. The systematic affinities of the fossil and the environments it inhabited were reconstructed by comparing the morphology of the fossils to that of their modern counterparts, along with their respective sedimentary contexts. Based on these comparisons, we conclude that the organism lived in a peritidal environment and was buried and fossilized in the shallow waters of an ancient carbonate platform. A formal transfer of the fossil to a new genus of fossil cyanobacteria thereby designated as Decastronema gen. nov. is proposed, honoring the contribution of Prof. Piero De Castro to paleontology.

Involvement of the compatible solutes trehalose and sucrose in the response to salt stress of a cyanobacterial Scytonema species isolated from desert soils

The response to moderate salt stress of a Scytonema species isolated from a soil crust in the arid region of central Australia was studied. An increase in intracellular trehalose and sucrose concentrations was detected by NMR and HPLC analysis following salt stress, maximal amounts being produced by exposure to 150 mM NaCl after 48 h. When the organism was subsequently returned to normal growth conditions, the cellular concentrations of these solutes decreased. The biosynthesis of trehalose and sucrose was studied and found, in both cases, to involve both sugar phosphate synthase and phosphatase enzymes. The combined synthase activities and the individual phosphatase activities in cell extracts were increased by salt stress. Trehalose phosphorylase was the only catabolic enzyme detected for trehalose; neither trehalase nor phosphotrehalase activities could be detected. This is the first report of trehalose phosphorylase activity in cyanobacteria. Both trehalose and sucrose phosphorylase activities increased in salt-stressed cells, whereas the activity of invertase did not change.

Influence of Microclimate on the Occurrence of Cyanobacteria in the Phyllosphere in a Premontane Rain Forest of Costa Rica

Abstract: The occurrence of cyanobacteria in the phyllosphere of several understory plants was investigated during a one and a half year study in a primary premontane rain forest in Costa Rica. Altogether, seven species of epiphyllous cyanobacteria were identified and are discussed here. The ecology of the two most frequent species in the understory, Scytonema javanicum and Sc. hofmannii, was studied in further detail. Within the Understory, the relative abundance of these species, as well as of epiphyllous bryophytes, was more influenced by air humidity than by light. The humidity, characterized as potential evaporation, also had influence on the pseudosuccession of the phyllosphere vegetation. While at moist sites bryophytes and both species of Scytonema appeared nearly simultaneously on 6–9‐month‐old leaves, at dryer sites Sc. javanicum, and especially Sc. hofmannii, appeared 6–9 months after bryophytes had established. On 13–15‐month‐old leaves bryophytes and Scytoriema were usually well established. On average, 20–30% of the leaf area of 2–5‐year old leaves of Spathacanthus hoffmannii (Acan‐thaceae, an abundant understory shrub) were covered by bryophytes, 2–3% by Sc. javanicum, and 0.1–0.2% by Sc. hofmannhi. An influence of phorophyte species on the occurrence and abundance of these two species of Scytonema could not be detected. However, Sc. hofmannii was more frequent on leaves with higher bryophyte cover, while Sc. javanicum was independent from bryophytes. A comparison of leaves from the understory and from the canopy showed that the composition and abundance of cyanobacteria species changed with height above forest floor.

Microclimatic parameters influencing nitrogen fixation in the phyllosphere in a Costa Rican premontane rain forest.

The acetylene reduction method was used to measure nitrogen fixation in the phyllosphere of attached leaves of different phorophytes under natural conditions in a premontane rain forest in Costa Rica. Maximum rates of nitrogen fixation (26 ng N · cm-2 leaf area · h-1) - mainly due to the activity of two species of Scytonema (Cyanobacteria) - were measured in the rainy season in bright sunlight. Rates of nitrogen fixation were correlated with the leaf area covered by Scytonema. In periods without precipitation the fixation activity decreased to zero within 2-3 days. As long as the epiphylls were sufficiently supplied with water, other microclimatic factors like temperature and light intensity also influenced nitrogen fixation rates, but to a lesser extent. Relative humidity and species of phorophyte showed no direct influence. It was concluded that the most important factor for nitrogen fixation in the phyllosphere was the availability of liquid water. Linking these results to meteorological data, the input of nitrogen by biological nitrogen fixation in the phyllosphere in the investigation area was estimated to be as much as 1.6 ± 0.8 kg N · ha-1 · year-1 per unit of leaf area index (LAI). For an LAI of 2 for the understory the nitrogen input would vary between 2 and 5 kg N · ha-1 · year-1. This work also demonstrates the importance of detailed knowledge of variation in microclimate throughout the year as a basis for extrapolation of the annual nitrogen input.

Cyanophycin and glycogen synthesis in a cyanobacterial Scytonema species in response to salt stress

The response to salinity of a Scytonema species isolated from the central Australian desert was studied. Under nitrogen-fixing conditions the addition of increasing concentrations of salt (NaCl) caused progressive inhibition of growth, with growth ceasing at 150 mM NaCl. This correlated with a progressive loss of nitrogenase activity, a low level of activity being retained at 150 mM NaCl. The inhibition of growth was overcome when KNO 3 (10 mM) was added to the growth medium. In response to the salt stress, cells accumulated the reserve compounds cyanophycin and glycogen. Time course experiments showed that they were steadily synthesized over 48 h, after which the concentrations stabilized. Cyanophycin synthesis was enhanced in salt-stressed cells grown in nitrate. When cells were restored to their normal growth medium the content of these substances decreased towards control levels.

Cyanophycin and glycogen synthesis in a cyanobacterialScytonemaspecies in response to salt stress

The response to salinity of a Scytonema species isolated from the central Australian desert was studied. Under nitrogen-fixing conditions the addition of increasing concentrations of salt (NaCl) caused progressive inhibition of growth, with growth ceasing at 150 mM NaCl. This correlated with a progressive loss of nitrogenase activity, a low level of activity being retained at 150 mM NaCl. The inhibition of growth was overcome when KNO3 (10 mM) was added to the growth medium. In response to the salt stress, cells accumulated the reserve compounds cyanophycin and glycogen. Time course experiments showed that they were steadily synthesized over 48 h, after which the concentrations stabilized. Cyanophycin synthesis was enhanced in salt-stressed cells grown in nitrate. When cells were restored to their normal growth medium the content of these substances decreased towards control levels.

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.

Uptake of Sodium and Potassium by Blue-Green Algae (Cyanobacteria)

Summary Tolypothrix ceylonica, Hapalosiphon intricatus, and two species of Calothrix (C. braunii and C. membranacea) showed absorption of sodium > 0.8 μg/mg algae dry wt., grown in a medium containing 1.425 mg Na/ml. These species of blue-green algae synthesized less biomass as compared to the species of Scytonema, Nostoc, Calothrix, and Aulosira. On supplementing the medium with graded concentration of potassium, a reduced Na/K ratio was observed, and the biomass production increased as the concentration of potassium increased up to a limit of 0.13 mg K/ml. No definite trend with protein synthesis could be observed.

A New Lichinodium Species from British Columbia

The new species Lichinodium canadense is described, and some morphological details of L. ahlneria and L. sirosiphoideum are given for comparison. The Lichinodium species belong to the smallest fruticose genus of the lichen family Lichinaceae. Hitherto, two species of the genus were known (Henssen, 1963, p. 83 ff.), Lichinodium sirosiphoideum Nyl. and L. ahlneri A. Henss., both occurring in Europe. Lichinodium sirosiphoideum grows epiphytic on other lichens in Fennoscandia, L. ahlneri has been found on spruce twigs in western Norway. In 1962, on a trans-Canadian excursion conducted by Dr. R. F. Cain, I collected a new Lichinodium species on the bark of red cedar in British Columbia. I name the lichen Lichinodium canadense after the country where it was found. In the recent lichen checklist of British Columbia by Otto and Ahti (1967), 99 genera are listed. Lichinodium can be added as the hundredth genus. The genus Lichinodium is characterized by its minute fruticose thallus composed of terete lobes which are translucent when moist. The lobes are delimited in the outer part by a sheath of several hyphal layers and contain two or more trichomes of a Scytonema species. Lichinodium sirosiphoideum and L. canadense are known only in the sterile state. In L. ahlneri the apothecia are produced in loose connection with the lobes (for details see Henssen, 1963). Lichinodium canadense A. Henss., sp. nov. (Fig. 1-2; 5A,B,D,F,G). Thallus minutissimus, 2-3 mm latus, fruticulosus, rosulatus, gelatinosus, fuscescens aut nigricans. Rami 0.4-0.8 mm longi et 0.04-0.06 mm lati. Apothecia et pycnidia ignota. Alga ad Scytonema pertinens. A Lichinodium sirosiphoideum praesertim magnitudine differt. CANADA. BRITISH COLUMBIA: Fraser River Basin, along Highway 1, E of Sicamous, on the bark of Thuja plicata in a mixed forest on a river bank, 1962, Henssen 14491d (HERB. HENSSEN-holotype; TRTC, UBC-iSotypes). Thallus minute fruticose, gelatinous brownish or blackish, in single rosettes (Fig. 5A) up to 2-3 mm in diameter, closely appressed to the substrate, or in larger, irregularly loosely-attached tufts (Fig. 5B). Rhizines colorless, scanty, in tufts. Lobes terete, translucent when moist, 0.4-0.8 mm long and 0.04-0.06 mm thick, monopodially branched, the branches frequently at right angles (Fig. 5D). Thallus sections (in lactic blue) 55-80,x thick. Hyphae extended mainly parallel in longitudinal section, a sheath of 2-4 hyphal layers without algae below the thallus 1 This study was supported by a grant from the Deutsche Forschungsgemeinschaft. I thank Mr. Hans Bundesmann for help in preparing Figure 5. 2 Botanisches Institut der Universitdit Marburg, Germany. This content downloaded from 157.55.39.27 on Mon, 05 Sep 2016 05:01:55 UTC All use subject to http://about.jstor.org/terms 272 THE BRYOLOGIST [Volume 71