Degradation of Bagasse Cellulose by Acremonium sp. w-398 (Department of Agricultural Chemistry)

砂糖きび畑土壌からバガスセルロースを資化分解できるAcremonium sp.w-398が分離された。バガスを炭素源とした培地における本菌株の生育及びバガスセルロースの分解性を調べた結果, NaOH溶液で前処理したバガスが本菌株の良好な基質となり, アルカリ溶液で抽出されるヘミセルロースも資化利用された。本菌株はアルカリ抽出液を含むアルカリ処理バガスで良好な生育を示し, バガスセルロースもよく分解された。本菌株は0.5%NaOH溶液を用いて120℃, 20分間処理したバガス培地で最も良好な生育を示し, 培養72時間で75%以上のバガスセルロースが分解された。本菌株によるバガスセルロースの分解性からみた培地中のバガス濃度は2.0%が適当で, 窒素源として用いる硫酸アンモニウムの濃度は0.25%が適当であった。本菌株はpH6.0∿8.0で良好な生育を示し, バガスセルロースもこのpH範囲でよく分解された。A bagasse-cellulose utilizing mold was isolated from soils of sugar-cane fields. The mold was identified as a member of the genus Acremonium by its morphological characteristics and named Acremonium sp. w-398. The strain was studied to determine the growth behavior on bagasse as a source of carbon and the degradability of bagasse cellulose. Native bagasse was hardly utilized by the strain, whereas the growth occurred when the strain was cultivated on bagasse treated with NaOH solution. Hemicelluloses in the alkali-treatment liquor, alkali-extract, were also utilized by the strain. Bagasse cellulose was degraded effectively when the strain was grown on the combined alkali-treated bagasse and alkali-extract. The maximal growth and bagasse-cellulose degradation were obtained when bagasse was treated with 0.5% NaOH solution at 120℃ for 20min. At least 75% of the original bagasse cellulose was degraded after 72hr cultivation. The most suitable concentration of bagasse in the medium for the cellulose degradation was 1.0 to 2.0%. Ammonium sulfate (0.2%) was the most effective nitrogen source for the growth and cellulose degradation. The best growth and cellulose degradation by the strain occurred within a pH range of 6.0 to 8.0