Ferchak J D, Pye E K
Department of Biochemistry and Biophysics, School of Medicine/G3, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
Biotechnol Bioeng. 1983 Dec;25(12):2865-72. doi: 10.1002/bit.260251205.
The saccharification of cellulosic substrates by cellulase from Thermomonospora fusca, strain YX, was influenced by the presence of various substances. Cellobiose was strongly inhibitory, reducing the activity against swollen cellulose to 25% at 5% concentration. Glucose had much less effect, reducing activity to 40% at 20% concentration. Ethanol was found to be only slightly inhibitory to the cellulase, reducing activity by about 15% at 6% concentration, but much more inhibitory to the cell-bound beta-glucosidase activity. Of the numerous metal ions examined, Ca(2+) and Co(2+) at 0.1mM-1.0mM concentration were found to be slightly activating under assay conditions, while 1.0mM Pb(2+) and Hg(2+) were the most inhibitory ions. The implications of these results for the design of commercial processes for ethanol production from cellulose are discussed.
来自嗜热栖热放线菌YX菌株的纤维素酶对纤维素底物的糖化作用受到多种物质的影响。纤维二糖具有强烈的抑制作用，在5%浓度时，对膨胀纤维素的活性降低至25%。葡萄糖的影响要小得多，在20%浓度时，活性降低至40%。发现乙醇对纤维素酶只有轻微的抑制作用，在6%浓度时活性降低约15%，但对细胞结合的β-葡萄糖苷酶活性抑制作用更强。在所检测的众多金属离子中，在测定条件下，0.1mM - 1.0mM浓度的Ca(2+)和Co(2+)有轻微的激活作用，而1.0mM的Pb(2+)和Hg(2+)是最具抑制作用的离子。讨论了这些结果对纤维素乙醇生产商业工艺设计的意义。
