Dae-Hyung Lee

Manufacture and Physiological Functionality of Korean Traditional Liquors by using Paecilomyces japonica

In order to develop a new traditional liquor by using Paecilomyces japonica, alcohol fermentation condition was investigated. Ethanol was produced maximally when 1% P. japoniea and 10% koji were added into mash and fermented by Saccharomyces cerevisiae at for 15 days. Sensory evaluation and physiological functionalities of P. japonica traditional liquors made by different addition () of the fungus were also determined and compared. As 0.1% P. japonica was added to mash, the liquor was best acceptable, and its fibrinolytic activity and nitrite scavenging activity were 11.2U and 19.8%, respectively.

Production of galactooligosaccharide by β-galactosidase fromKluyveromyces maxianus varlactis OE-20

A galactooligosaccharide (GalOS)-producing yeast, OE-20 was selected from forty seven strains of yeast growing in Korean traditionalMeju (cooked soybean) and the yeast was tentatively identified asKluyveromyces maxianus varlactis by its morphology and fermentation profile. A maximum yield of 25.1%(w/w) GalOS, which corresponds to 25.1 g of GalOS per liter, was obtained from the reaction of 100 g per liter of lactose solution at 30°C, pH 7.0 for 18 h with an intracellular crude β-galactosidase. Glucose and galactose were found to inhibit GalOS formation. The GalOS that were purified by active carbon and celite 545 column chromatography were supplemented in MRS media and a stimulated growth was observed of some intestinal bacteria. In particular the growth rate ofBifidobacterium infantis in the GalOS containing MRS broth increased up to 12.5% compared to that of the MRS-glucose broth during a 48 h incubation period.

Production of the Acetylcholinesterase Inhibitor from Yarrowia lipolytica S-3

The acetylcholinesterase (AChE) inhibitor of Yarrowia lipolytica S-3 was maximally produced when it was incubated at 30°C for 36 h in an optimal medium containing 1% yeast extract, 2% peptone and 2% glucose, with an initial pH 6.0. The final AChE inhibitory activity under these conditions was an IC50 value of 64 mg/ml. After partial purification of the AChE inhibitor by means of systematic solvent extraction, the final IC50 value of the partially purified AChE inhibitor was 0.75 mg/ml. We prepared a test product by using the partially purified AChE inhibitor and then determined its stability for the development of a new antidementia commercial product. The test product was stable at room temperature for 15 weeks.