When cultures of biotin-requiring mutant of Brevibacterium divaricutum NRRL-2311 were treated in early logarithmic phase with penicillin (2 -3 units/ml) in a glucose-mineral medium under excess supply of biotin, large amounts of a high-molecular-weight material accumulated in the medium. The phenomenon could not be observed with cultures run in parallel from which penicillin was omitted. Chemical analyses of the excreted material isolated from the media of I-h and 24-h penicillin-treated cultures, showed that the main constituents were peptidoglycan components of noncross-linked structure bearing both L-and D-alanine residues ; evidence was also obtained for the occurrence of extractable lipid material, non-amino sugars and organic phosphate.Under identical conditions, the excretion of peptidoglycan could be induced by ampicillin and cloxacillin, respectively, but not by bacitracin. Addition of penicillin to biotin-requiring mutant of M . glutamicus yielded similar results, indicating that the phenomenon was not restricted to the Brev. divaricutum strain. This suggests that excretion of peptidoglycan material by the two biotin-requiring mutants might be the result of two events, (a) a change in the osmotic barrier of the cell and (b) specific inhibition of cross-link formation in peptidoglycan induced by penicillin.Several procedures were examined for the isolation and purification of the peptidoglycan complex excreted by penicillin-treated Brev. mutant. Suitable labelling experiments with L-[U-14C]glutamic acid and analyses of lysozyme digests of the purified fractions, suggest that some of the components might contain murein fragments covalently linked to a polysaccharide portion.During our studies on the accumulation of amino acids into the culture broth of the biotin-requiring mutant of Brevibacteriurn divaricatum (NRRL-231 l ) , it has been observed that in the presence of low doses of penicillin the extracellular accumulation of glutamate is accompanied by the excretion of some highmolecular-weight material. The first observations were made in cultures grown on glucose media containing biotin, to which penicillin G (2-10 units/ml) was added at the early logarithmic phase; incubations were carried out at 28 "C for 24, 48 and 72 h, respectively.When a growing culture was incubated simultaneously with 14C-labelled L-glutamic acid and penicillin for 24 h and the supernatant fluid submitted to gel fractionation, a substantial portion of radioactivity eluted a t low retention volumes. I n contrast, in the culture fluid of the control from which penicillin had been omitted, no radioactivity associated with some high-molecular-weight material could be detected. When subjected to paper electrophoresis and chromatography, the radioactive material excreted by penicillin-treated cells did not move from the origin. Hydrolysis of a sample in 6 M HCl a t 100 "C revealed diaminopimelic acid as one of the amino acid components.Since diaminopimelate is present in no other cellular material than in murein, the excreted mater...

Summary.A leucine aminopeptidase was purified to homogeneity from Streptomyces rimosus culture filtrates, which are waste broth of oxytetracycline bioproduction process. Purification procedure includes ultrafiltration and chromatography on CM-Sephadex, AH-Sepharose and FPLC Mono S column.The enzyme is a monomer with molecular weight of 27,500 Daltons and pI of 7.3, stable in broad pH range and up to 70°C. It is a metallo enzyme dependent o n C a 2+ ions for its full activity. By its specificity it is a true aminopeptidase active on amino acid amide, arylamide, peptide and ester bonds. The hydrolysing activity shows preference for leucine at the N-terminal position of substrates, also acts on aromatic acids and methionine, but does not release glycine, proline, acidic amino acids or D-amino acid residues.

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An environmentally more convenient reaction for the production of industrially important aryl ethyl ethers (ArOEts) is described. ArOEts were selectively obtained in essentially quantitative yields by the reaction of corresponding (hetero)aromatic alcohols (ArOHs) with diethyl carbonate as the environmentally friendly alkylating reagent in the presence of N,N-dimethylacetamide used as polar aprotic cosolvent, and sodium ethoxide as the base. The reactions were carried out in the air under atmospheric pressure at 1378C. Reaction equilibrium was shifted by distilling the ethanol from the reaction mixture. All ArOEts were isolated by evaporation of the reaction mixture, and subsequent extraction with water and diethoxymethane. The ethylation agent and used solvents were non-toxic, recyclable and biologically degradable. Wastewater from the extraction was successfully treated by Fenton oxidation and returned to the next work-up process.

In this prospective study, 35,550 neonates were examined shortly after birth by a team of orthopaedic surgeons. They diagnosed 775 unstable or dislocated hips in 656 babies; there were two teratological dislocations. Treatment was first with a Frejka pillow and, if this failed to give a normal hip, a Pavlik harness at three months. Early clinical examination did not identify 21 infants who were found to have subluxation or dislocation of the hip at the three-month review. The number of missed cases declined during the study, however, reflecting the increasing experience of the examiners. One case of avascular necrosis occurred in the group treated from birth and one in the late-diagnosed group. Open reduction was necessary only in the two teratological dislocations. Experienced examiners are needed for accurate clinical diagnosis; and treatment should be started before the baby is discharged from the maternity ward.