Abstract:

The epoxy and amino resin carriers have been used for immobilizing the β\|galactosidase from Aspergillus candidus, respectively. The amino resin showed superiority over epoxy carrier with 72.5% of recovery percentage, and 145 U/g of enzyme activity; while the epoxy carrier with 24% and 24 U/g. Both of the immobilized enzyme shared similar optimal pH and temperature with the free enzyme, but the immobilized by amino resin enjoys higher thermostability, which could retain 60% of activity after used for 20 times. The maximum galacto\|oligosaccharides (GOS) yield reached 87 g/L by using amino resin immobilized enzyme and 300 g/L initial lactose.

Key words: epoxy carrier, amino resin, β\, galactosidase, GOS

摘要：

固定化β\|半乳糖苷酶具有易于分离、可重复使用等优点，在低聚半乳糖和低乳糖乳生产中具有重要应用。比较了两种固定化酶载体—环氧基树脂（EP）和氨基功能树脂（HA），固定化亮白曲霉来源β\|半乳糖苷酶的效果。氨基功能载体酶固定化率为72.5%，固定化酶活力可达到145 U/g，而环氧基树脂酶固定化率为24%，固定化酶活力为24 U/g。两种固定化β\|半乳糖苷酶的最适温度、最适pH与游离酶相同。但是氨基载体固定化酶的热稳定性明显高于游离酶及环氧基载体固定化酶，其在重复使用20次后，酶活力保持在60%左右。以300 g/L的乳糖为起始浓度，通过该氨基载体固定化酶生产低聚半乳糖（GOS），最大产量为87 g/L。

关键词: 环氧基树脂；氨基功能树脂；β\, 半乳糖苷酶；低聚半乳糖