Journal of Microbiology

Jae Heung Lee

2 Articles

Growth of Issatchenkia orientalis in Aerobic Batch and Fed-batch Cultures: Hyung Tai Shin , Yoo Beom Lim , Jong Ho Koh , Jong Yun Kim , Soon Young Baig , Jae Heung Lee; J. Microbiol. 2002;40(1):82-85.

Abstract PDF: The aerobic batch growth of Issatchenkia orientalis DY252 with glucose and fructose medium was investigated at 32 C and pH 5.0. Aerobic ethanol production was evident with yeast I. orientalis. A diauxic lag of about 1 h between growth on glucose and growth on ethanol during batch culture was observed. However, no diauxic growth occurred with fructose. As the incubation temperature was increased from 32 to 39 C, viability at the end of each batch culture declined significantly, from 93 to 43%. Unlike the effect of temperature, viability was not greatly affected by incubation pH, and cell yield values in a range of 0.45-0.48 were obtained. In order to overcome overflow metabolism, a fed-batch culture under glucose limitation was carried out. Compared with aerobic batch culture, about 10% improvement in cell yield was achieved with a fed-batch culture in optimal conditions.

Reaction Route for Enzymatic Production of Neofructo-oligosaccharides from Sucrose Using Penicillium citrinum Cells: Jae Heung Lee , Satoru Shinohara; J. Microbiol. 2001;39(4):331-333.

Abstract PDF: The production of oligosaccharides using Penicillium citrium cells at high sugar concentrations was investigated at 50 C and pH 5.0. Both 1-kestose and neokestose were produced from sucrose, while both nystose and tetrasaccharide were produced from 1-kestose. However, no reaction product was obtained from neofructo-oligosaccharides such as neokestose. Based on these experimental results, a hypothetical reaction route was proposed to illustrate how neofructo-oligosaccharides are formed from 1-kestose.

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