[The virus inactivating efficacy of peracids and peracidous disinfectants (author's transl)]. / Die virusinaktivierende Wirkung von Persäuren und Persauren Desinfektionsmitteln.

It has always been an aim to develop chemicals able to kill a broad spectrum of microorganisms. Research in this field led to peracids inactivating vegetative bacterial forms, spores, fungi and viruses. Since liquid peracids are very unstable, powders were developed which dissolved in water, formed peracids. In this paper the inactivating efficacy of peracids derived from powders as well as of pure peracids is presented. It is shown that both inactivate the following viruses: poliomyelitisvirus type 1, coxsackievirus B3, adenovirus type 5 and SV40. The most resistant viruses were the picornaviruses, especially coxsackievirus B3. But in all cases, inactivation is in accordance with the guidelines of the Deutsche Vereinigung zur Bekämpfung der Viruskrankheiten (DVV) (15). Furthermore, it is shown that pure peracids are more reactive than peracids formed from powders. But with all peracids there remains residual infectivity, which may be due to inhomogenic virus populations.

[The influence on efficacy of formaldehyd and phenol against bacterial cells I. Effect of drying, cations and pH-value (author's transl)]. / Beeinflussung der Wirkung von Formaldehyd bzw. Phenol auf Bakterienzellen.

1. When cells of E. coli and Staph. aureus are dried, the efficacy of phenol is reduced but the efficacy of formaldehyde is increased. 2. A change of the aw-value by addition of salts changes the efficacy of formaldehyde as well as that of phenol. For these tests the chlorides of various alkali and alkaline earth metals were used in different concentrations. 3. The optimal efficacy of phenol and formaldehyde within the tested concentration gradientis caused by different concentrations of the ions: In low concentrations the efficacy of formaldehyde is optimally increased, the efficacy of phenol, however, attains a minimum at this concentration range. By higher concentrations of ions the efficacy of phenol is increased, that of formaldehyde is reduced. 4. The position of the cations in the periodic system also plays a role in the influence on the efficacy of the phenol and formaldehyde respectively. The cations of the lower periods from the main groups I and II favour the damage to the cells by phenol, the cations of the higher periods favour the damage by formaldehyde.

The electron transport system of the anaerobic Propionibacterium shermanii: cytochrome and inhibitor studies.

1. Electron transport particles obtained from cell-free extracts of Propionibacterium shermanii by centrifugation at 105000 times g for 3 hrs oxidized NADH, D,L-lactate, L-glycerol-3-phosphate and succinate with oxygen and, except for succinate, with fumarate, too. 2. Spectral investigation of the electron transport particles revealed the presence of cytochromes b, d and o, and traces of cytochrome alpha1 and a c-type cytochrome. Cytochrome b was reduced by succinate to about 50%, and by NADH, lactate or glycerol-3-phosphate to 80--90%. 3. The inhibitory effects of amytal and rotenone on NADH oxidation, but not on the oxidation of the other substrates, indicated the presence of the NADH dehydrogenase complex, or "site I region", in the electron transport system of P. shermanii. 4. NQNO inhibited substrate oxidations by oxygen and fumarate, as well as equilibration of the flavoproteins of the substrate dehydrogenases by way of menaquinone. The inhibition occurred at low concentrations of the inhibitor and reached 80--100%, depending on the substrate tested. The site of inhibition of the respiratory activity was located between menaquinone and cytochrome b. In addition, inhibition of flavoprotein equilibration suggested that NQNO acted upon the electron transfer directed from menaquinol towards the acceptor to be reduced, either cytochrome b or the flavoproteins, which would include fumarate reductase. 5. In NQNO-inhibited particles, cytochrome b was not oxidized by oxygen-free fumarate, but readily oxidized by oxygen. It was concluded from this and the above evidence that the branching-point of the electron transport chain towards fumarate reductase was located at the menaquinone in P. shermanii. It was further concluded that all cytochromes were situated in the oxygen-linked branch of the chain, which formed a dead end of the system under anaerobic conditions. 6. Antimycin A inhibited only oxygen-linked reactions of the particles to about 50% at high concentrations of the inhibitor. Inhibitors of terminal oxidases were inactive, except for carbon monoxide.