Muneharu Goto

Hydrolysis of triolein by lipase in a hollow fiber reactor

Abstract Hydrolysis of triolein by lipase was carried out in a hollow fiber membrane reactor, oleic acid and glycerol being formed as products. It was found that hydrolysis of triolein by lipase in the hollow fiber reactor can be quantitatively explained by a Michaelis-Menten mechanism at the interface, together with competitive inhibition by oleic acid, diffusion of all chemical species and adsorption of lipase at the interface between the aqueous and organic phases. The reaction model could be applied to a wide range of conversions in the membrane reactor.

Peroxidase activity and stability of surfactant-heme complex in nonaqueous media

A surfactant-heme complex was prepared from hemin using a water-in-oil emulsion with a synthetic nonionic surfactant. The heme complex was soluble in anhydrous benzene with peroxidase activity for the oxidation of o-phenylene-diamine using tert-butyl hydroperoxide as an oxidant. An absorption spectrum of the heme complex in benzene was distinct from that of free heme in an aqueous buffer solution owing to the different aggregation states in the respec-tive solution. Moreover, the heme complex could not be decomposed in benzene even in excess of the hydroper-oxide due to enhanced stability.

Extraction of Rare Earth Metals Using Liquid Surfactant Membranes in a Mixco Extractor

The extraction of rare earth metals with liquid surfactant membranes, which contained 2-ethylhexyl-mono-2-ethylhexylphosphonic acid (PC-88A) as a carrier and sorbitan monooleate (Span 80) or L -glutamic acid dioleyl ester quaternary ammonium chloride as a surfactant, was conducted in a Mixco extractor. The concentration profile of rare earth metals along the column was measured. The experimental results were analysed by the backflow model taking into account the interfacial reaction between rare earth metals in the continuous aqueous phase and the carriers in the liquid membrane phase. The concentration profile for each of the two rare earth metals (La, Y) in a dual-component solution along the column was successively simulated by using the interfacial reaction rate constants obtained in previous batchwise experiments.

Synthesis Reaction of Glyceride with Surfactant-Coated Lipase.

Surfactant-coated lipase was prepared with a newly synthesized surfactant. The synthesis reaction of glycerides was investigated using the lipase and substrates of glycerol and oleic acid. The activity of the enzyme, which is significantly higher than that of native enzyme, depends strongly on the water content, and the optimal water content is about 3040 mol%. The main product of this enzyme reaction was monoolein under the present experimental conditions.