Wartmann T, Krüger A, Adler K, Duc B M, Kunze I, Kunze G
Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany.
Antonie Van Leeuwenhoek. 1995 Oct;68(3):215-23. doi: 10.1007/BF00871818.
Arxula adeninivorans Ls3 is described as an ascomycetous, arthroconidial, anamorphic, xerotolerant yeast, which was selected from wood hydrolysates in Siberia. By using minimal salt medium or yeast-extract-peptone-medium with glucose or maltose as carbon source it was shown that this yeast is able to grow at up to 48 degrees C. Increasing temperatures induce changes in morphology from the yeast phase to mycelia depending on an altered programme of gene expression. This dimorphism is an environmentally conditioned (reversible) event and the mycelia can be induced at a cultivation temperature of 45 degrees C. Depending on the morphology of strain Ls3 (yeast phase or mycelia) the secretion behaviour as well as the spectrum of polypeptides accumulated in the culture medium changed. The activities of the accumulated extracellular enzymes glucoamylase and invertase were 2 to 3 times higher in cultures grown at 45 degrees C than in those grown at 30 degrees C. While the level of the glucoamylase protein secreted from mycelia between 45 and 70 hours did not change, biochemical activity decreased after a cultivation time of 43 hours. It was shown that this effect depended on both the catabolic repression of the glucoamylase by glucose and the thermal inactivation of this enzyme in media without or with low concentrations of starch or maltose.
嗜腺阿舒囊霉Ls3被描述为一种子囊菌、节孢子、无性型、耐干燥酵母，它是从西伯利亚的木材水解物中筛选出来的。使用以葡萄糖或麦芽糖作为碳源的基本盐培养基或酵母提取物蛋白胨培养基表明，这种酵母能够在高达48摄氏度的温度下生长。温度升高会根据基因表达程序的改变诱导形态从酵母相转变为菌丝体。这种二态性是一种受环境条件影响（可逆）的事件，在45摄氏度的培养温度下可诱导产生菌丝体。根据菌株Ls3的形态（酵母相或菌丝体），其分泌行为以及培养基中积累的多肽谱会发生变化。在45摄氏度下培养的培养物中积累的胞外酶糖化酶和转化酶的活性比在30摄氏度下培养的培养物中高2至3倍。虽然在45至70小时之间从菌丝体分泌的糖化酶蛋白水平没有变化，但在培养43小时后生化活性下降。结果表明，这种效应既取决于葡萄糖对糖化酶的分解代谢阻遏，也取决于该酶在无淀粉或低浓度淀粉或麦芽糖的培养基中的热失活。
