Continuous cellobiose hydrolysis using self-immobilized β-glucosidase fromAspergillus phoenicis QM 329 in a fluidized-bed reactor

Aspergillus phoenicis QM 329 was grown in the shape of beads in shake flasks and in an air-lift fermentor. The production of β-glucosidase started when the carbon source, glucose, was consumed. The β-glucosidase activity was retained in the beads at a pH below 6.0. The influence of bead diameter on enzyme activity and the pH and temperature optima for cellobiose hydrolysis has been studied. The enzyme-containing beads were used in a fluidized-bed reactor for continuous cellobiose hydrolysis, and a productivity of 2.0 g/L-h at a substrate conversion of 76% was obtained. The self-immobilized β- glucosidase is a stable and reusable enzyme with a half-life of 700 h when operating at 50°C and pH 4.8.

     

Catalytic and thermal transformations of methyl- and isopropylcyclobutanes

Conclusions The thermal decomposition of the methyl- and isopropylcyclobutanes in the presence of quartz powder proceeds only with cleavage of the ring at two bonds, while in the presence of amorphous aluminosilicate and zeolite NM the additional reactions of ring opening, cleavage of groups containing one carbon atom, and hydrogen redistribution take place.Translated from Izvestya Akademii Nauk SSSR, Seriya Khimieheskaya, No. 1, pp. 170–172, January, 1973.     

Loaded and unloaded optical response of polyester model materials

The optical behavior of mixtures of rigid and flexible polyester resins when loaded and unloaded under constant strain-rate and varying test temperature are characterized. New evidence about the photoplastic method of analyzing deformed but unloaded models is presented through experiments with tensile or compressive uniaxial specimens, diametrically compressed disks and beams under pure bending, which were analyzed during loading, unloading and after being unloaded.     

Magnetogasdynamic flows in short high-current electric arcs

Qualitative features of the dynamic, thermal, and electromagnetic fields in systems that simulate short high-current electric arcs are investigated by numerical integration of the Navier—Stokes equations.