PENGARUH PENAMBAHAN URASIL DALAM MEDIA FERMENTASI TERHADAP HASIL β-GLUKAN DARI DUA GALUR AGROBACTERIUM

Abstract

Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Influence of Uracil in Fermentation Media on β -Glucan Production by Agrobacterium Radiobacter A 1.5 and Agrobacterium sp . Bro 1.2.1 . Optimum β -glucan production can be achieved by an optimum condition in the fermentation media . Uracil, as a precursor of UDP-glucose, may act as a glucose donor in the formation of polysaccharides such as β -glucan. It is expected that addition of certain quantity of uracil into the fermentation media in a suitable growth phase of Agrobacterium radiobacter A 1.5 and Agrobacterium sp. Bro 1.2.1, will significantly increase the β -glucan production. In this investigation, 0.025%; 0.05% or 0.1% of uracil were added into the fermentation media during the logarithmic phase (24 hour) or stationary phase (46 hour) of growth. The β -glucan product was evaluated from the β -glucan ( crude ) dry-weight and from the β -glucan content. Beta -glucan content was determined as glucose by the Hisamatsu-AOAC and HPLC methods. The highest β -glucan ( crude ) dry-weight produced by the A. 1.5 was in a medium containg 0.025% uracil (24 hour), whilst by the A. Bro 1.2.1 was in a medium containg 0.1% uracil (46 hour), both higher than control. The highest β -glucan content produced by the A. 1.5 (27.03%) was in a medium containg 0.025% uracil (46 hour), while control produced only 23.28%. The highest β -glucan content produced by the Bro 1.2.1 (29.34%) was in a medium containg 0.025% uracil (24 hour), while control produced only 28.75%. Two-way anova analysis showed that there were no significant influence difference (α = 0,05) from various concentration of uracil in either growth phases, to the yield of β -glucan ( crude ) dry-weight nor to the β -glucan equivalent glucose content. Keywords: Agrobacterium radiobacter A 1.5, Agrobacterium sp. Bro 1.2.1 mutant, β-glucan, Uracil