Jouni Jokela

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The production of hepatotoxic cyclic heptapeptides, microcystins, is almost exclusively reported from planktonic cyanobacteria. Here we show that a terrestrial cyanobacterium Nostoc sp. strain IO-102-I isolated from a lichen association produces six different microcystins. Microcystins were identified with liquid chromatography-UV mass spectrometry by their(More)
A specific quantitative real-time PCR (qPCR) method was developed for the quantification of hepatotoxin nodularin-producing Nodularia, one of the main bloom-forming cyanobacteria in the Baltic Sea. Specific PCR primers were designed for subunit F of the nodularin synthetase gene (ndaF), which encodes the NdaF subunit of the nodularin synthetase gene complex(More)
Anabaena is a filamentous, N(2)-fixing, and morphologically diverse genus of cyanobacteria found in freshwater and brackish water environments worldwide. It contributes to the formation of toxic blooms in freshwater bodies through the production of a range of hepatotoxins or neurotoxins. In the Baltic Sea, Anabaena spp. form late summer blooms, together(More)
Anabaenopeptins are a diverse family of cyclic hexapeptide protease inhibitors produced by cyanobacteria that contain a conserved ureido bond and D-Lys moiety. Here we demonstrate that anabaenopeptins are assembled on a nonribosomal peptide synthetase enzyme complex encoded by a 32 kb apt gene cluster in the cyanobacterium Anabaena sp. strain 90.(More)
Cyanobactins are small cyclic peptides that are produced by a diverse selection of cyanobacteria living in symbioses as well as terrestrial, marine, or freshwater environments. They include compounds with antimalarial, antitumor, and multidrug reversing activities and potential as pharmaceutical leads. Cyanobactins are produced through the proteolytic(More)
Lichens are symbiotic associations between fungi and photosynthetic algae or cyanobacteria. Microcystins are potent toxins that are responsible for the poisoning of both humans and animals. These toxins are mainly associated with aquatic cyanobacterial blooms, but here we show that the cyanobacterial symbionts of terrestrial lichens from all over the world(More)
Microcystins are small cyclic heptapeptide toxins produced by a range of distantly related cyanobacteria. Microcystins are synthesized on large NRPS-PKS enzyme complexes. Many structural variants of microcystins are produced simulatenously. A recombination event between the first module of mcyB (mcyB1) and mcyC in the microcystin synthetase gene cluster is(More)
Ribosomal peptides are produced through the posttranslational modification of short precursor peptides. Cyanobactins are a growing family of cyclic ribosomal peptides produced by cyanobacteria. However, a broad systematic survey of the genetic capacity to produce cyanobactins is lacking. Here we report the identification of 31 cyanobactin gene clusters from(More)
The late summer mass occurrences of cyanobacteria in the Baltic Sea are among the largest in the world. These blooms are rarely monotypic and are often composed of a diverse assemblage of cyanobacteria. The toxicity of the blooms is attributed to Nodularia spumigena through the production of the hepatotoxic nodularin. However, the microcystin hepatotoxins(More)
The bloom-forming cyanobacterium Nodularia spumigena produces toxic compounds, including nodularin, which is known to have adverse effects on various organisms. We monitored the primary effects of nodularin exposure on physiological parameters in Spinachia oleracea. We present the first evidence for the uptake of nodularin by a terrestrial plant, and show(More)