| life cycle energy and greenhouse gas profile of a process for the production of ammonium sulfate from nitrogen-fixing photosynthetic cyanobacteria. | in this paper, an alternative means for nitrogen fixation that may consume less energy and release less greenhouse gases than the haber-bosch process is explored. a life-cycle assessment was conducted on a process to: culture the cyanobacterium, anabaena sp. atcc 33047, in open ponds; harvest the biomass and exopolysaccharides and convert these to biogas; strip and convert the ammonia from the biogas residue to ammonium sulfate; dry the ammonium sulfate solution to ammonium sulfate crystals and ... | 2011 | 22226591 |
| arsenic biomethylation by photosynthetic organisms. | arsenic (as) is a ubiquitous element that is widespread in the environment and causes numerous health problems. biomethylation of as has implications for its mobility and toxicity. photosynthetic organisms may play a significant role in as geochemical cycling by methylating it to different as species, but little is known about the mechanisms of methylation. methylated as species have been found in many photosynthetic organisms, and several arsenite s-adenosylmethionine (sam) methyltransferases h ... | 2012 | 22257759 |
| toxopsis calypsus gen. nov., sp. nov. (cyanobacteria, nostocales) from cave 'francthi', peloponnese, greece - morphological and molecular evaluation. | one new cyanobacterial genus toxopsis lamprinou & pantazidou gen. nov. was found in fresh material of cave 'francthi'(peloponnese, greece) and isolated in cultures; additionally, ecological data of the sampling sites are provided concerning the environmental parameters [photosynthetically active radiation (par), temperature (t), relative humidity (rh)]. morphological characters and the life cycle of the type species toxopsis calypsus lamprinou & pantazidou sp. nov. were studied under lm, sem and ... | 2012 | 22247210 |
| net light-induced oxygen evolution in photosystem i deletion mutants of the cyanobacterium synechocystis sp. pcc 6803. | oxygenic photosynthesis in cyanobacteria, algae, and plants requires photosystem ii (psii) to extract electrons from h(2)o and depends on photosystem i (psi) to reduce nadp(+). here we demonstrate that mixotrophically-grown mutants of the cyanobacterium synechocystis sp. pcc 6803 that lack psi (δpsi) are capable of net light-induced o(2) evolution in vivo. the net light-induced o(2) evolution requires glucose and can be sustained for more than 30min. utilizing electron transport inhibitors and c ... | 2012 | 22266340 |
| natural product biosyntheses in cyanobacteria: a treasure trove of unique enzymes. | cyanobacteria are prolific producers of natural products. investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. in this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. we especially emphasize modular nonribosomal peptide synthetase (nrps) and polyketide synthase (pks) pathways and highlight the u ... | 2011 | 22238540 |
| identification of a new nanornase in bartonella. | in escherichia coli, only one essential oligoribonuclease (orn) can degrade oligoribonucleotides of five residues and shorter in length (nanorna). in bacillus subtilis, nrna and nrnb, which do not have any sequence similarity with orn, have been identified as functional analogs of orn. sequence comparisons did not allow identifying orn, nrna, or nrnb homologues in the genomes of the chlamydia/cyanobacteria and alphaproteobacteria family members. screening a genomic library from bartonella birtle ... | 2012 | 22262096 |
| biochemical and pathological toxic effects induced by the cyanotoxin cylindrospermopsin on the human cell line caco-2. | cylindrospermopsin (cyn), a cyanotoxin produced by several freshwater cyanobacteria, causes human intoxications and animal mortalities. the present study focuses on the cytotoxic effects of cyn on caco-2 cells at 24 and 48 h. the basal cytotoxicity endpoints studied were total protein content (tp), neutral red uptake (nr) and reduction of the tetrazolium salt (mts). the effect of non-cytotoxic concentrations of cyn on the generation of intracellular reactive oxygen species (ros), γ-glutamylcyste ... | 2011 | 22227240 |