為探討森林土壤纖維素分解菌應用，纖維素分解菌由塔塔加森林土壤以Mandels-Reese培養基強化分離後 以16S rDNA分析法鑑定。纖維素分解酵素活性以1% CMC為基質測定，而濾紙分解活性則以Whatman No. 1濾 紙為基質測定。並測定Michaelis動力學參數和最大反應速度。十株纖維素分解活性較高之分離株分別進行16S rDNA順序分析，其中兩株纖維素分解菌AR-129和AR-138具有高纖維素分解酵素活性。分離株AR-129和AR-138 分別與Janthinobacterium sp.和Pedobacter sp.有最高序列相似性。因而分離株AR-129命名為Janthinobacterium sp. AR-129，而分離株AR-138則命名為Pedobacter sp. AR-138。分離株AR-129和AR-138分別在pH 4.0有最高纖維素分 解酵素活性3.89 U ml -1和在pH 7.0有最高纖維素分解酵素活性4.33 U ml -1。兩個分離株所生產之纖維素分解酵素 皆為耐熱性，其最適溫度為50℃ ，可供生物技術工業應用。分離株AR-129所生產之纖維素分解酵素其Km 3.36 mg ml -1和Vmax 3.98 μmol ml -1 min -1，而分離株AR-138所生產之纖維素分解酵素其Km 4.05 mg ml -1和Vmax 3.70 μmol ml -1 min -1。分離株Janthinobacterium sp. AR-129和Pedobacter sp. AR-138為具有纖維素分解酵素生產之潛力菌株。 這兩株菌所生產之纖維素分解酵素具高熱穩定性和纖維素分解酵素多樣化，可供各類工業上使用，具工業應 用潛力。

To investigate the cellulolytic bacteria in forest soils, cellulolytic bacteria were isolated from forest soils by enrichment method and identified by 16S rDNA analysis. Cellulolytic microbes were isolated from Tatachia forest soils with Mandels-Reese medium. The cellulolytic microbes were identified by 16S rDNA sequencing. Cellulase activity was determined with 1% CMC as substrate while filter paper activity was determined with Whatman No. 1 filter paper as substrate. The kinetic parameters of Michaelis constant and maximum velocity were also determined. Ten high cellulolytic isolated strains were identified by 16S rDNA sequencing analysis. Two of these cellulolytic strains, AR-129 and AR-138, had high cellulase activities. Strains AR-129 and AR-138 had the highest sequence similarity with Janthinobacterium sp. and Pedobacter sp., respectively. Therefore, strain AR-129 was assigned as Janthinobacterium sp. AR-129, and strain AR-138 was assigned as Pedobacter sp. AR-138. The maximum cellulase activity of strains AR-129 and AR-138 were 3.89 U ml -1 at pH 4.0 and 4.33 U ml -1 at pH 7.0, respectively. The cellulases produced by both strains are thermostable with optimal temperature 50ºC that can be used for biotechnological industrial application. The cellulase of strain AR-129 had Km 3.36 mg ml -1 and Vmax 3.98 μmol ml -1 min -1, while strain AR-138 exhibited Km 4.05 mg ml -1 and Vmax 3.70 μmol ml -1 min -1. The strains Janthinobacterium sp. AR-129 and Pedobacter sp. AR-138 are the potential cellulase producing bacterial strains. The cellulases produced by these strains showed high thermal stability and a complex set of cellulolytic enzymes. The thermo-stable enzymes can be used in various industrial applications.