Production,Purification, and Characterization of Thermoanaerobacterium thermosaccharolyticum Glucoamylase

Glucoamylase from Thermoanaerobacterium thermosaccharolyticum ATCC 7956 (DSM 571) was produced in extracellular form. It was purified to homogeneity by two separate methods, one with two chromatographic steps and the other with three. This glucoamylase is closely related to glucoamylases from Clostridium sp. G0005 and T. thermosaccharolyticum DSM 572. Activities and K_M values with maltose substrate are less than one‐tenth and about fourfold, respectively, those of Aspergillus niger glucoamylase. T. thermosaccharolyticum glucoamylase is about twenty times as thermostable as A. niger glucoamylase and its optimal pH is somewhat higher at 4.9; however, it is produced in much lower activities. Sorbitol strongly stabilizes A. niger glucoamylase.     

Preparation of Cyclobutyl Group Carrying Cyclobutanones and Related Synthetic Building Blocks

Compounds 3, 4, 10, 12, 16, 17, and 19 have been prepared as possible starting materials for liquid crystals containing two cyclobutyl moieties combined in a 1,3‐fashion. Further typical conversions of these have been tested giving 5, 7, and 14 for example. Useful intermediates 16 and 17 were also made.     

Kinetic Investigations on the Hydrogenation of 3-Ketosucrose

Sucrose can be converted to allosucrose by a sequence of a biotechnical oxidation and a hydrogenation. The second step was found to be highly stereoselective with high yield and without any side products. The kinetics of the hydrogenation was examined with respect to the influence of the starting materials and the catalyst. A quantitative correlation for the influence of the concentrations is given. Furthermore, the influence of mass transfer processes was considered. Under unfavorable conditions gas liquid mass transfer can be rate-limiting.