[Implementation of the new EU Bathing Water Directive in Germany]. / Umsetzung der neuen EG-Badegewässerrichtlinie in Deutschland.

A revised version of the Bathing Water Directive 76/160/EWG has been elaborated to include scientific progress in risk assessment of bathing-related illness. The new Bathing Water Directive 2006/7/EC came into force on March 24, 2006, and will have to be implemented in the federal states within two years. The new bathing water directive contains several positive innovations which will improve a protection of the bathers namely i) health related indicators, ii) uniform detection methods, iii) requirements for active bathing water management, and iv) stricter standards for coastal waters. In Germany, the 16 federal states of the Federal Republic of Germany - the Länder - are responsible for monitoring bathing waters and for implementing the new bathing water directive into national law. A common master directive is being written by a joint working-group to ensure comparable implementation in all parts of Germany. An immediate application of the new directive is not possible since the parameter "intestinal enterococci" is currently not routinely monitored. It was decided to start monitoring according to the new directive in Germany in 2008. This will allow the first classification of bathing waters according to the new directive in 2011.

Direction of proton translocation in proteoliposomes formed from purple membrane and acidic lipids depends on the pH during reconstitution.

The reconstitution of proton pumping activity in proteoliposomes formed by brief sonication of purple membrane and lipid dispersions was studied as a function of pH. Proteoliposomes reconstituted using cardiolipin showed light-dependent proton extrusion when formed at a pH below 2.75 and proton uptake when formed above pH 2.75. Several other acidic lipids including halobacterial lipids behaved similarly. The experiments suggest that the degree of dissociation of the lipid phosphate groups determines the preferential orientation of bacteriorhodopsin in reconstituted proteoliposomes.

Temperature-sensitive mutants of the yeast fatty-acid-synthetase complex.

By genetic complementation analysis, 88 independently isolated temperature-sensitive fatty acid synthetase mutants have been assigned to the six different fas-complementation groups II (fas 1), III (fas 1), Vb (fas 1), VI (fas 2), VIII (fas 2) and IX (fas 2). The complementation groups Va, Vc, Vd, IV and VII observed among nonconditional fas-mutants have not been found among the temperature-sensitive strains studied. From the failure to detect pantetheine-deficient conditional fas-mutants it is concluded that the yease acyl-carrier protein has an exceptionally stable tertiary structure. Furthermore, the lack of temperature-sensitive mutants of complementation group IV possibly indicates that this group specifically represents only nonsense and frameshift mutations. Almost half of the temperature-sensitive fas 1 and fas 2 mutants studied exhigited non-complementing characteristics. These results confirm the existence of non-complementing fas1 and fas2 missense mutations. From this it is concluded that both fatty acid synthetase loci encode multifunctional polypeptide chains rather than several monofunctional component enzymes. The possible existence of an independent acyl-carrier protein, as suggested by the genetic data reported in this study, is discussed. With 10 different temperature-sensitive fas1 and fas2 mutants the dependence of cellular growth rates on growth temperature and fatty acid supplementation was determined. With all mutants studied fatty-acid-independent growth was completely suppressed at non-permissive temperatures (34 -37 degrees C). In fatty-acid-supplemented media, however, these mutants exhibited the same growth characteristics as wild-type yeast cells. In contrast to this, wild-type yeast growth was found to be fatty-acid-independent at all temperatures studied. Other than in vivo, the purified fatty acid synthetase isolated from five different temperature-sensitive fas1 and fas2 mutants exhibited in vitro no increased thermolability compared to the wild-type enzyme. From this it is concluded that the specific conformation of fatty acid synthetase subunits either forms only at the ribosomal level during translation, or that this conformation is stabilized by the assembly of subunits into the multienzyme complex structure.

Malonyl and palmityl transferase-less mutants of the yeast fatty-acid-synthetase complex.

146 independently isolated mutants of the fatty acid synthetase gene locus fas 1 were subdivided into six different complementation groups. Three of these groups, Va, Vb and Vd, have not been described before. The mutant fatty acid synthetases isolated from representatives of complementation group Vb were specifically deficient in two component enzymes at the same time, the malonyl and palmityl transferases. Among more than 180 fas 1 and fas 2 mutants systematically screened for malonyl and palmityl transferase activities no mutant was found affected in only one of these two fatty acid synthetase component enzymes. From this it is concluded that both transfer reactions are catalyzed by the same enzyme. In any malonyl transferase-less fatty acid synthetase, neither of the two known malonyl binding sites, i.e. enzyme-bound pantetheine and the non-thiol binding site, accepts malonate. This indicates that malonate is transferred to both groups by the same enzyme. So far, no acetyl transferase-less fas mutants have been characterized. On the other hand, the mutants of two fas 1 complementation groups, Va and Vd, though negative in overall fatty acid synthetase activity had no deficiency in any of the known component enzymes which can be tested in vitro. A possible interrelationship between both findings is discussed.