25 psychrotrophic protease-forming bacteria isolated from glaciers were identified as follows: Pseudomonas spp. (1 8 strains), Fluvobucterium spp. (3 strains), Xunthomonas multophilia (2 strains), Aeromonus hydrophila ( 1 strain) and Bacillus sp. (1 strain). Characteristics of proteolytic activity in cell-free culture supernatants were studied. Proteases produced by 40% of the bacteria showed a maximum azocaseinolytic activity around 40 "C and pH 7. Enzymes were rapidly inactivated after heating at 50 "C. pI-values of proteases ranged from > 9.5 to 7.0. Sensitivity to EDTA indicates that most proteases are metalloproteases. Proteases of psychrotrophs could be differentiated from proteases of mesophiles by a lower temperature optimum, a lower activation energy and a higher sensitivity against heat treatment.

During a systematic screening of basidiomycetes for new antibiotic substances PA 789/80, a polyacetylenic antibiotic with activity against Gram-positive bacteria, yeasts and moulds, was isolated from the culture extract of Marasmius alliaceus. The neutral compound showed the same characteristic finger type of ultraviolet spectrum as marasin.1) It differs from known antibiotic substances found in submerged culture of the genus Marasmius1 8 and closely related genera.°-1=' Marasmius alliaceus, strain BC 2020, was maintained on BM-medium (glucose, 30 g; Witte peptone, 10g; KH2PO4, 0.5g; MgSO4, 0.5g; Ca(NO3)2, 0.5 g; FeSO4, 10 mg; MnSO4, 6 mg; ZnCl2, 4 mg; CuSO4, 1mg; inositol, 50 mg; aneurine, 50 pg; biotin, I (g; agar, 15 g per liter). Mycelium from ten agar slants was used to inoculate ten 500-m1 flasks each containing 80 ml of BM-medium. The seed cultures were incubated on a rotary shaker at 24°C for 8 days. After homogenizing under sterile conditions these cultures were used as inoculum for ten 2liter flasks each containing 250 ml of the same medium. The fermentation was conducted at 24'C for 12 days with agitation. During the fermentation the antibiotic activity of the culture broth was estimated after extraction with ethyl acetate. For isolation the culture broth containing the antibiotic substance was filtered through Celite, and the filtrate (3 liters) was extracted twice with 1.5 liters each of ethyl acetate. The organic phase was concentrated by solvent evaporation.

Design, Synthesis and Stability of N-Acyloxymethyl-and N-Aminocarbonyloxymethyl-2-azetidinones as Human Leukocyte Elastase Inhibitors. -The title compounds (VIII) and (X) are timedependent irreversible inhibitors of HLE. The most potent compounds are (Xb), (Xc), and (VIIIb) (no yields given). -(CLEMENTE, A.; DOMINGOS, A.; GRANCHO, A. P.; ILEY, J.; MOREIRA, R.; NERES, J.; PALMA, N.; SANTANA, A. B.; VALENTE, E.; Bioorg. Med.