Abstract
Galactooligosaccharlde (GOS) is a kind of functional oligosaccharides that can be used as a food ingredient and a cosmetic additive. In this paper, characteristics of GOS synthesis by cellulase, using lactose as a substrate, were investigated. Penicillium funiculosum cellulose was found to be the most efficient for GOS production among six cellulose tested. The optimum pH and temperature for GOS production were 5.0 and $50^{\circ}C$, respectively. There was an optimum ratio of lactose concentration to enzyme loading; the value was 10 (w/w). The reaction pattern of P. funiculosum cellulase is consistent with that of microbial ${\beta}$-galactosidase which shows transgalactosylation activity. Amounts of GOS produced from 20% (w/v) lactose after 6 h incubation at $50^{\circ}C$, were 23% (w/w) based on total saccharide in the reaction medium. The GOS % increased with initial lactose concentration in the range of 5 to 20%. The products mainly consisted of a trisaccharide and tetrasaccharide from HPLC and TLC analysis. Among enzymes involved in transgalactosylation reaction, high molecular weight fractions over 50,000 Da, presumably ${\beta}$-glucosldase, were considered to be responsible for GOS production. Using this cellulose, a direct synthesis of galactosyl g1ucoside including GOS could be readily achieved with lactose as a galactosyl donor.
식품 및 화장품의 첨가제로 사용되는 기능성 올리고당인 갈락토올리고당을 생룰로스 가수분해 효소를 이용하여 생산하였다. 여섯가지의 효소 시료 가운데, P Penicillium funiculosum에서 유래한 셀룰로스 가수 분해 효소가 가장 높은 올리고당 생산 수율을 보였다. 올리고당 생산을 위한 최적온도와 pH는 각각 $50^{\circ}C$,와 5.0이었으며 유당농도와 효소농도사at의 최 적비는 lO(w/w) 이었다. 시간에 따른 올리고당 생산 반응의 경향성은 유당분해 효소 반응과 유사하였 으며 초기 유당농도가 증가함에 따라 생성되는 올리 고당의 농도가 증가하였다. 최척반응조건에서 20% (w/v)의 유당으로 부터 최고 23%(w/w)의 올리고 땅을 얻을 수 있었다. 생성된 올라고당의 성분은 고 속액체 크로마토그래프와 박층 크로마토그래프 분석 을 통하여 삼당과 사당으로 이루어져 있음을 확인하였다.
