Small changes in pH have direct effects on marine bacterial community composition: a microcosm approach.

As the atmospheric CO(2) concentration rises, more CO(2) will dissolve in the oceans, leading to a reduction in pH. Effects of ocean acidification on bacterial communities have mainly been studied in biologically complex systems, in which indirect effects, mediated through food web interactions, come into play. These approaches come close to nature but suffer from low replication and neglect seasonality.

Excess nitrate loads to coastal waters reduces nitrate removal efficiency: mechanism and implications for coastal eutrophication.

Terrestrial ecosystems are becoming increasingly nitrogen-saturated due to anthropogenic activities, such as agricultural loading with artificial fertilizer. Thus, more and more reactive nitrogen is entering streams and rivers, primarily as nitrate, where it is eventually transported towards the coastal zone. The assimilation of nitrate by coastal phytoplankton and its conversion into organic matter is an important feature of the aquatic nitrogen cycle.

An improved method for counting bacteria from sediments and turbid environments by epifluorescence microscopy.

We present a new procedure for effectively detaching particle-associated bacteria by 10% (v/v) methanol and sonication which is particularly suitable for samples with a high particle load and sediments. We also optimized the sample preparation by applying the highly dsDNA-specific fluorescent stain SybrGreen I together with an optically brilliant mounting medium (polyvinylalcohol 4-88, 'moviol') in one step. The new protocol allows a much faster, easy and less toxic handling of samples as compared to other methods.