Quantitative real-time PCR methods are increasingly being applied for the enumeration of toxic cyanobacteria in the environment. However, to justify the use of real-time PCR quantification as a monitoring tool, significant correlations between genotype abundance and actual toxin concentrations are required. In the present study, we aimed to explain the concentrations of three structural variant...

The nitrogen-rich phycobiliproteins are efficient light-harvesting pigments of cryptophytes, cyanobacteria, and rhodophytes. Whereas it is well established that certain cyanobacteria mobilize their phycobiliproteins in response to nitrogen deprivation, the effect of nitrogen stress on cryptophyte physiology has been studied only rarely. We compared the effects of nitrogen and phosphorus depleti...

Background: The soft tissue around dental implants forms a barrier between the oral environment and the periimplant bone and a crucial factor for long-term success of therapy is development of a good abutment/soft-tissue seal. Sol-gel derived nanoporous TiO2 coatings have been shown to enhance soft-tissue attachment but their effect on adhesion and biofilm formation by oral bacteria is unknown....

Many cyanobacteria produce microcystins, hepatotoxic cyclic heptapeptides that can affect animals and humans. The effects of photosynthetically active radiation (PAR) on microcystin production by Microcystis strain PCC 7806 were studied in continuous cultures. Microcystis strain PCC 7806 was grown under PAR intensities between 10 and 403 micro mol of photons m(-2) s(-1) on a light-dark rhythm o...

The amino acid L-arginine inhibits bacterial coaggregation, is involved in cell-cell signaling, and alters bacterial metabolism in a broad range of species present in the human oral cavity. Given the range of effects of L-arginine on bacteria, we hypothesized that L-arginine might alter multi-species oral biofilm development and cause developed multi-species biofilms to disassemble. Because of ...

Elevated atmospheric CO2 increases plant C fixation, and much of the soluble C content of deciduous leaf litter entering streams is leached as dissolved organic C (DOC). The effects of DOC from trembling aspen (Populus tremuloides Michaux) leaf litter grown under elevated (ELEV 1⁄4 720 ppm) and ambient (AMB1⁄4 360 ppm) CO2 on stream periphyton were measured during a 35-d experiment in outdoor a...

The ongoing rise in atmospheric pCO2 and consequent increase in ocean acidification have direct effects on marine calcifying phytoplankton, which potentially alters carbon export. To date it remains unclear, firstly, how nutrient regime, in particular by coccolithophores preferred phosphate limitation, interacts with pCO2 on particulate carbon accumulation; secondly, how direct physiological re...