Biely P, Krátký Z, Vrsanská M, Urmanicová D
Eur J Biochem. 1980;108(1):323-9. doi: 10.1111/j.1432-1033.1980.tb04726.x.
Extracellular endo-1,4-beta-xylanase synthesis in the yeast Cryptococcus albidus is largely inducible. During growth on wood xylans the yeast produces the enzyme in amounts two orders of magnitude greater than on other carbon sources, including xylose. The enzyme can be induced in washed glucose-grown cells by xylan and beta-1,4-xylooligosaccharides. Among the oligosaccharides only xylobiose was not degraded extracellularly, therefore it appears to be the natural inducer of the enzyme. Xylobiose as a metabolisable inducer is effective at low concentrations and constant availability to cells. At high concentration of xylobiose the inductive effect is less pronounced because of catabolic repression by degradation products. Methyl beta-D-xylopyranoside was found to serve as a non-utilizable inducer of beta-xylanase. The enzyme induced by the glycoside appears to be identical with that produced by the cells during growth on xylan.
酵母浅白隐球酵母中胞外内切 - 1,4 - β - 木聚糖酶的合成很大程度上是可诱导的。在以木聚糖为碳源生长时，该酵母产生的这种酶的量比在包括木糖在内的其他碳源上生长时高出两个数量级。木聚糖和β - 1,4 - 木寡糖可在经洗涤的以葡萄糖为碳源生长的细胞中诱导该酶的产生。在这些寡糖中，只有木二糖不会在细胞外被降解，因此它似乎是该酶的天然诱导物。作为可代谢诱导物的木二糖在低浓度且细胞持续可利用的情况下是有效的。在高浓度木二糖时，由于降解产物的分解代谢阻遏作用，诱导效果不太明显。发现甲基β - D - 吡喃木糖苷可作为β - 木聚糖酶的不可利用诱导物。由该糖苷诱导产生的酶似乎与细胞在木聚糖上生长时产生的酶相同。
