| extracellular cyanobacterial substances inhibit microbial growth. | cyanobacteria are able to produce extracellular substances with different biological activities and behaviors. the marine cyanobacteria anabaena sp. strain hi 26 and oscillatoria subtilissima strain bo 62 cause significant color changes in their growth media, while viscosity of the medium is influenced by rivularia sp. strain bo 85 and oscillatoria limnetica strain flo 1. sterile-filtered media, pregrown with the organisms mentioned above, were used to study the influence of changes in media bio ... | 2000 | 11334306 |
| genetic and morphological characterization of rivularia and calothrix (nostocales, cyanobacteria) from running water. | in this study, a polyphasic approach was adopted to investigate natural freshwater (river and stream) samples of rivularia colonies and isolated strains of cyanobacteria with a high degree of trichome tapering (genera rivularia and calothrix). analysis of the phycocyanin (pc) operon and the intervening intergenic spacer (cpcba-igs) and 16s rrna gene sequences were used for genetic characterization. in addition, a molecular fingerprinting method, temperature-gradient gel electrophoresis, which al ... | 2008 | 18218948 |
| antiprotozoal, antitubercular and cytotoxic potential of cyanobacterial (blue-green algal) extracts from ireland. | cyanobacteria (= blue-green algae) are prolific producers of structurally distinct and biologically active metabolites. in the continuation of our search for new sources of anti-infective natural products, we have assessed the in vitro antiprotozoal (plasmodium falciparum, trypanosoma brucei rhodesiense, t. cruzi, leishmania donovani) and antitubercular (mycobacterium tuberculosis) potential of samples of two terrestrial cyanobacteria, nostoc commune (collected when desiccated and wet) and rivul ... | 2011 | 21615033 |
| [photocontrol of the synthesis of chlorophyll a and phycocyanin in the cyanobacterium calothrix crustacea schousboe]. | chlorophyll a and phycocyanin synthesis in the cyanobacterium calothrix crustacea schousboe (ecophene rivularia bullata) have been studied in white light after the application of red and green light pulses. the light quality produces a complementary pattern in the pigment synthesis. chlorophyll synthesis is stimulated by red light pulses whereas phycocyanin synthesis is by green light pulses. because the effect of red light on chlorophyll synthesis shows some far-red photoreversibility, the acti ... | 1991 | 1798852 |
| strains of the cyanobacterial genera calothrix and rivularia isolated from the baltic sea display cryptic diversity and are distantly related to gloeotrichia and tolypothrix. | strains of the cyanobacterial genus calothrix display pronounced tapering filaments. these cyanobacteria are benthic, have a worldwide distribution and are among the most easily recognizable cyanobacterial genera. however, it is not clear whether cyanobacterial strains assigned to the genus calothrix constitute a natural monophyletic group. we sequenced 16s rrna genes from 42 cyanobacterial cultures and environmental samples belonging to the genus calothrix, and the morphologically similar gener ... | 2007 | 17466025 |
| populations of exopolysaccharide-producing cyanobacteria and diatoms in the mucilaginous benthic aggregates of the tyrrhenian sea (tuscan archipelago). | the microalgal community of benthic mucilages sampled in various sites of the tuscan archipelago during the period may 1999-july 2002, was always dominated by diatoms. synedra, licmophora and navicula were the most frequently found genera, their presence having been observed within all the period under study; other ten genera of diatoms were found in the benthic mucilages, but their presence was dependent on the month and the year of observation. as concerns the cyanobacterial community, the fil ... | 2005 | 16271382 |
| nitrogen and phosphorus in soil solutions and drainage streams in upper teesdale, northern england: implications of organic compounds for biological nutrient limitation. | the availability of nitrogen (n) and phosphorus (p) to organisms is a fundamental control on the ecology of uplands in the british isles, yet there has been relatively little consideration of the role of organic forms of these nutrients. n and p fractions in soil solutions and drainage streams were determined at monthly intervals over 1 year from widdybank fell, upper teesdale national nature reserve, an upland area of northern england. nitrogen was present in inorganic and organic forms at rela ... | 2003 | 14499531 |
| phylogenetic and molecular clock inferences of cyanobacterial strains within rivulariaceae from distant environments. | heterocyst-forming cyanobacteria are important players at both evolutionary and ecological scales, but to date it has been difficult to establish their phylogenetic affiliations. we present data from a phylogenetic and molecular clock analysis of heterocystous cyanobacteria within the family rivulariaceae, including the genera calothrix, rivularia, gloeotrichia and tolypothrix. the strains were isolated from distant geographic regions including fresh and brackish water bodies, microbial mats fro ... | 2011 | 21208268 |