Thermal and chemical disinfection of water and biofilms: only a temporary effect in regard to the autochthonous bacteria.

Thermal and chemical disinfection of technical water systems not only aim at minimizing the level of undesired microorganisms, but also at preventing excessive biofouling, clogging and interference with diverse technical processes. Typically, treatment has to be repeated in certain time intervals, as the duration of the effect is limited. The transient effect of disinfection was demonstrated in this study applying different treatments to water and biofilms including heat, chlorination, a combination of hydrogen peroxide and peracetic acid and monochloramine.

The D-A-(C) index: A practical approach towards the microbiological-ecological monitoring of groundwater ecosystems.

Groundwater is not only a vital resource, but also one of the largest terrestrial aquatic ecosystems on Earth. However, to date, ecological criteria are often not considered in routine groundwater monitoring, mainly because of the lack of suitable ecological assessment tools. Prokaryotic microorganisms are ubiquitous in groundwater ecosystems even under the harshest conditions, making them ideal bioindicators for ecological monitoring.

Complete nitrification by Nitrospira bacteria.

Nitrification, the oxidation of ammonia via nitrite to nitrate, has always been considered to be a two-step process catalysed by chemolithoautotrophic microorganisms oxidizing either ammonia or nitrite. No known nitrifier carries out both steps, although complete nitrification should be energetically advantageous. This functional separation has puzzled microbiologists for a century.

Cohn's Crenothrix is a filamentous methane oxidizer with an unusual methane monooxygenase.

135 years ago Ferdinand Cohn, the founder of bacteriology, microscopically observed a conspicuous filamentous bacterium with a complex life cycle and described it as Crenothrix polyspora. This uncultured bacterium is infamous for mass developments in drinking water systems, but its phylogeny and physiology remained unknown. We show that C.