A chemically active filtration membrane with incorporated lanthanum oxide nanoparticles enables the removal of bacteria and phosphate at the same time and thus provides a simple device for preparation of drinking water and subsequent safe storage without using any kind of disinfectants.

a b s t r a c tIn the Gram-positive methylotroph Bacillus methanolicus, methanol oxidation is catalyzed by an NAD-dependent methanol dehydrogenase (Mdh) that belongs to the type III alcohol dehydrogenase (Adh) family. It was previously shown that the in vitro activity of B. methanolicus Mdh is increased by the endogenous activator protein Act, a Nudix hydrolase. Here we show that this feature is not unique, but more widespread among type III Adhs in combination with Act or other Act-like Nudix hydrolases. In addition, we studied the effect of site directed mutations in the predicted active site of Mdh and two other type III Adhs with regard to activity and activation by Act.

The capability of tracing a food product along its production chain is important to ensure food safety and product authenticity. For this purpose and as an application example, recently developed Silica Particles with Encapsulated DNA (SPED) were added to milk at concentrations ranging from 0.1 to 100 ppb (μg per kg milk). Thereby the milk, as well as the milk-derived products yoghurt and cheese, could be uniquely labeled with a DNA tag. Procedures for the extraction of the DNA tags from the food matrixes were elaborated and allowed identification and quantification of previously marked products by quantitative polymerase chain reaction (qPCR) with detection limits below 1 ppb of added particles. The applicability of synthetic as well as naturally occurring DNA sequences was shown. The usage of approved food additives as DNA carrier (silica = E551) and the low cost of the technology (<0.1 USD per ton of milk labeled with 10 ppb of SPED) display the technical applicability of this food labeling technology.