An extracellular serine alkaline protease of Bacillus clausii GMBAE 42 was produced in protein-rich medium in shake-flask cultures for 3 days at pH 10.5 and 37 degrees C. Highest alkaline protease activity was observed in the late stationary phase of cell cultivation. The enzyme was purified 16-fold from culture filtrate by DEAE-cellulose chromatography followed by (NH(4))(2)SO(4) precipitation, with a yield of 58%. SDS-PAGE analysis revealed the molecular weight of the enzyme to be 26.50 kDa. The optimum temperature for enzyme activity was 60 degrees C; however, it is shifted to 70 degrees C after addition of 5 mM Ca(2+) ions. The enzyme was stable between 30 and 40 degrees C for 2 h at pH 10.5; only 14% activity loss was observed at 50 degrees C. The optimal pH of the enzyme was 11.3. The enzyme was also stable in the pH 9.0--12.2 range for 24 h at 30 degrees C; however, activity losses of 38% and 76% were observed at pH values of 12.7 and 13.0, respectively. The activation energy of Hammarsten casein hydrolysis by the purified enzyme was 10.59 kcal mol(-1) (44.30 kJ mol(-1)). The enzyme was stable in the presence of the 1% (w/v) Tween-20, Tween-40,Tween-60, Tween-80, and 0.2% (w/v) SDS for 1 h at 30 degrees C and pH 10.5. Only 10% activity loss was observed with 1% sodium perborate under the same conditions. The enzyme was not inhibited by iodoacetate, ethylacetimidate, phenylglyoxal, iodoacetimidate, n-ethylmaleimidate, n-bromosuccinimide, diethylpyrocarbonate or n-ethyl-5-phenyl-iso-xazolium-3'-sulfonate. Its complete inhibition by phenylmethanesulfonylfluoride and relatively high k (cat) value for N-Suc-Ala-Ala-Pro-Phe-pNA hydrolysis indicates that the enzyme is a chymotrypsin-like serine protease. K (m) and k (cat) values were estimated at 0.655 microM N-Suc-Ala-Ala-Pro-Phe-pNA and 4.21 x 10(3) min(-1), respectively.

Four Gram-negative, moderately halophilic, exopolysaccharide-producing strains, designated AAD6 T , AAD4, AAD17 and AAD21, were isolated from Ç amaltı Saltern Area, a wildlife reserve in Sasalı, I˙zmir province located in the Aegean Region of Turkey. The isolates grew at an optimum NaCl concentration of 10 % (w/v). The major cellular fatty acids were C 16 : 0 , C 18 : 1 v7c, C 16 : 1 v7c and C 12 : 0 3OH, respectively and the predominant lipoquinone was ubiquinone Q-9. The G+C content of the genomic DNA of strains AAD6

Aims:The isolation and identification of new Bacillus sp. capable of growing under highly alkaline conditions as alkaline protease producers. Methods and Results: A Bacillus strain capable of growing under highly alkaline conditions was isolated from compost. The strain is a Gram-positive, spore-forming, motile, aerobic, catalase-and oxidase-positive, alkaliphilic bacterium and designated as GMBAE 42. Good growth of the strain was observed at pH 10. The strain was identified as Bacillus clausii according to the physiological properties, cellular fatty acid composition, G + C content of genomic DNA and 16S rRNA gene sequence analyses. The result of 16S rRNA sequence analyses placed this bacterium in a cluster with B. clausii. The G + C content of the genomic DNA of the isolate GMBAE 42 was found to be 49 mol%. The crude extracellular alkaline protease produced by the isolate showed maximal activity at pH 11AE0 and 60°C. Conclusions: The results suggest that isolated strain GMBAE 42 is a new type of B. clausii capable of growing at pH 10AE0 and produce extracellular alkaline protease very active at pH 11AE0. Significance and Impact of the Study: Isolated strain could be used in commercial alkaline protease production and its enzyme can be considered as a candidate as an additive for commercial detergents.

Six new 1,3-diorganylimidazolidin-2-ylidene (NHC) gold(I) complexes of the type [Au(NHC) 2 ] + (1-6), were synthesized by reacting [AuCl(PPh) 3 ] with 1,3-dimesitylimidazolidin-2-ylidene or bis(1,3-dialkylimidazolidin-2-ylidene). The complexes 1-6 were fully characterized by elemental analyses and spectroscopic data. The placement of mesityl or para-substituted benzyl groups on the nitrogen atoms of the ring of the complexes leads to the particularly active antibacterial agents evaluated in this work. It is worth noting that the p-methoxybenzyl derivative (2) inhibited the growth of Pseudomona aeruginosa, Staphylococcus epidermidis, Staphylococcus aureus and Enterococcus faecalis with minimum inhibitory concentration (MIC) values of 3.12 µg ml −1 , 6.25 µg ml −1 , 3.12 µg ml −1 and 3.12 µg ml −1 respectively. In contrast, the analogous p-dimethylaminobenzyl derivative (3) is effective only against Escherichia coli (MIC = 3.12 µg ml −1 ).

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