Candida wickerhamii NRRL Y-2563 expressed β-glucosidase activity (3 to 8 U/ml) constitutively when grown aerobically in complex medium containing either glycerol, succinate, xylose, galactose, or cellobiose as the carbon source. The addition of a high concentration of glucose (>75 g/liter) repressed β-glucosidase expression (<0.3 U/ml); however, this yeast did produce β-glucosidase when the initial glucose concentration was ≤50 g/liter. When grown aerobically in medium containing glucose plus the above-listed carbon sources, diauxic utilization of the carbon source was observed and the expression of β-glucosidase was glucose repressed. Surprisingly, glucose repression did not occur when the cells were grown anaerobically. When grown anaerobically in medium containing 100 g of glucose per liter, C. wickerhamii produced 6 to 9 U of enzyme per ml and did not demonstrate diauxic utilization of glucose-cellobiose mixtures. To our knowledge, this is the first report of apparent derepression of a glucose-repressed enzyme by anaerobiosis.
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机译：当在含有甘油，琥珀酸酯，木糖，半乳糖或纤维二糖作为碳源的复杂培养基中需氧生长时，柳条假丝酵母NRRL Y-2563组成型表达β-葡萄糖苷酶活性（3至8 U / ml）。加入高浓度的葡萄糖（> 75 g /升）会抑制β-葡萄糖苷酶的表达（<0.3 U / ml）；但是，当初始葡萄糖浓度≤50g / l时，该酵母确实会产生β-葡萄糖苷酶。当在含有葡萄糖和上述碳源的培养基中需氧生长时，观察到碳源的双交换利用，并且β-葡萄糖苷酶的表达被葡萄糖抑制。令人惊讶地，当细胞厌氧生长时没有发生葡萄糖阻抑。当在每升含100克葡萄糖的培养基中厌氧生长时，柳条杆菌每毫升产生6到9 U的酶，并且没有证明葡萄糖-纤维二糖混合物的双生利用。据我们所知，这是厌氧菌明显降低葡萄糖抑制酶的抑制作用的首次报道。
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