Trichoderma harzianum 유래 β-Mannanase의 정제 및 Picea abies Galactosyl Glucomannomannan 가수분해 올리고당의 중합도별 Bifidobacterium spp.에 대한 생육활성

Abstract

Beta-mannanase from Trichoderma harzianum was purified by Sephadex G-100 column chromatography. The specific activity of the purified enzyme was 8.44 units/mL protein, representing an 56.27-fold purification of the original crude extract. The final preparation thus obtained showed a single band on SDS-polyacrylamide gel electrophoresis. Its molecular weight was determined to be 52.5 kDa. Picea abies galactosyl glucomannan was hydrolyzed by the purified β-mannanase, and then the hydrolysates were separated by activated carbon column chromatography. The main hydrolysates were composed of D.P. (degree of polymerization) 6, 8, and 9 galactosyl glucomannooligosaccharides. To investigate the effects of Picea abies galactosyl glucomannanooligosaccharides on in the vitro growth of Bifidobacterium longum, B. bifidum, B. animalis, B. breve, B. infantis, B. adolescentis, and B. auglutum, Bifidobacterium spp. were cultivated individually on a modified-MRS medium containing carbon sources such as D.P. 6, 8, and 9 galactosyl glucomannooligosaccharides. B. longum grew up 14.3-fold and 9.4-fold more effectively after treatment with D.P. 6 and D.P. 8 galactosyl glucomannooligosaccharides compared to those with standard MRS medium. Especially, D.P. 6 was more effective than D.P 9 galactosyl glumannooligosaccharides with regard to the growth of Bifidobacterium spp.