Purification and preliminary characterization of a xylanase from Thermomyces lanuginosus strain SS-8

Thermomyces lanuginosus SS-8 was isolated from soil samples that had been collected from near self-heating plant material and its extracellular cellulase-free xylanase purified approximately 160-fold using ion exchange chromatography and continuous elution electrophoresis. This xylanase was thermoactive (optimum temperature 60 °C) at pH 6.0 and had a molecular weight of 23.79 kDa as indicated by SDS-PAGE electrophoresis. The xylanase rapidly hydrolyzed xylan directly to xylose without the production of intermediary xylo-oligosaccharides within 15 min of incubation under optimum conditions. This trait of rapidly degrading xylan to xylose as a sole end-product could have biotechnological potential in degradation of agro-wastes for bioethanol manufacturing industry

Enzymatic properties of a novel thermostable, thermophilic, alkaline and chelator resistant amylase from an alkaliphilic Bacillus sp. isolate ANT-6

A thermostable alkaline ?-amylase producing Bacillus sp. ANT-6 was isolated from soil samples. Enzyme synthesis occurred at temperatures between 25 and 45°C with an optimum of 37°C. There was a slight variation in amylase synthesis within the pH range 7 and 11 with an optimum pH of 9. The optimum temperatures for amylase production and growth were the same. Analyses of the enzyme by sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed a single band, which show amylolytic activity, detected in starch-gel. The relative molecular mass of the partial purified enzyme was estimated to be 94 500 Da. The enzyme showed optimum activity at pH 10.5 and 80°C. The partial purified enzyme was highly active in the alkaline range of pH (9.5-13), and it was completely active up to 100°C retaining 85.5% initial activity at pH 10.5. Enzyme activity was enhanced in the presence of 5 mM CaCl2 (110%) and 3 mM PMSF (103%), and inhibition with 5 mM by Zn, Na, Na-sulphide, EDTA (10 mM), Urea (8 M) and SDS (0.1%) was obtained 36.9, 21.5, 22.2, 4.90, 86% and 10.27, respectively. The enzyme was stable (55%) at high alkaline pH for 24 h. So our result showed that the enzyme was both alkaline, thermostable, thermopile and chelator resistant. The ANT-6 amylase enzyme may be suitable in liquefaction of starch, in detergent and textile industries and in other industrial applications. © 2003 Elsevier Science Ltd. All rights reserved.FEF 98.5This research supported by the Cukurova University Research Fund (FEF 98.5)