摘要：Palm kernel cake (PKC) is a promising source of prebiotics, since it contains high amount of β-mannan which can be further hydrolyzed to manno-oligasaccharides (MOS), a prebiotic. Therefore, this research was carried out to analyze the capability of a bacterial isolate (A2 isolates) previously isolated from soils sample from around IPB campus to hydrolyze PKC. Based on 16S-DNA analysis, isolate A2 was identified as Brevibacillus borstelensis. Mannanase of A2 isolate had an optimum condition at 90 oC and pH 7. Mannanase activity of crude extracts using Locust Bean Gum (LBG) and PKC as substrates were 0.37U/mL and 0.032U/mL, respectively. However, the most favorable production of oligosaccharides based on the degree of polymerization was obtained after 72-h of incubation with the ratio of substrate:enzyme, 1.2:1, on 1.5% PKC as substrate. The manno-oligosaccharides prebio-tic obtained was found to interfere the growth of both lactic acid bacteria (Lactobacillus casei) and pathogenic microflora (Escherichia coli). E. coli apparently could not use this prebiotic as the carbon sources, in contrast to L. casei. Substitution of carbon source in medium with prebiotics reduced the capability of L. casei to produce organic acids. It is concluded that local A2 isolate (B. borstelensis) produces mannanase which can be used to produce prebiotics from PKC.
其他摘要：Komponen utama dari bungkil inti sawit (BIS) adalah β-manan yang dapat digunakan dalam produksi prebiotik Manno-oligosakarida (MOS). Penelitian ini bertujuan mengkarakterisasi kemampuan isolat bakteri A2 yang diisolasi dari sampel tanah di sekitar kampus IPB dalam mendegradasi BIS. Berdasarkan analisis 16S-DNA isolat A2 teridentifikasi sebagai Brevibacillus borstelensis. Mananase isolat A2 memiliki kondisi optimum pada suhu 90 o C dan pH 7. Aktivitas mananase isolat A2 pada media dengan Locust Bean Gum (LBG) dan BIS berturut turut adalah 0.37U/ml dan 0.032U/ml. Perbandingan substrat:enzyme: 1.2:1, pada substrat BIS 1.5% memberikan derajat polimerisasi terbaik bagi produksi oligosakarida. Prebiotik MOS ini dapat mempengaruhi pertumbuhan Escherichia coli patogen dan Lactobacillus casei. E. coli tidak dapat menggunakan prebiotik ini sebagai sumber karbon dibandingkan L. casei. Substitusi sumber karbon dengan prebiotik menurunkan kemampuan L. casei dalam memproduksi asam organik. Disimpulkan bahwa isolat lokal A2 (B. borstelensis) menghasilkan mananase yang dapat digunakan untuk menghasilkan prebiotik dari BIS.
