Abstract

Despite the advancements of enzyme immobilization, improved immobilization techniques and new sources of supporting material is still a necessity. In this work, we have immobilised different enzymes such as α-amylase, α-glucosidase, lipase and catalase onto bacterial magnetosomes extracted from magnetotactic bacteria (MTB). Among the four enzymes, catalase and lipase showed significant increase in enzyme activity whereas the other two showed reduced activity when compared to the free enzyme. The free catalase activity was found to be 300.9 U/mg whereas the immobilised catalase activity was found to be 534.0 U/mg. The enzyme activity after immobilisation increased by 33.5% when compared to free enzyme. The spectrophotometric studies on the lipase activity with p-nitrophenyl acetate as substrate showed 2–5% increase in the activity for the immobilised lipase over free enzyme. However, the activity of magnetosome immobilised α-glucosidase and α-amylase decreased by 6 and 20%, respectively, compared to free enzyme. The decline in activity might be due to the insufficient coupling of enzymes with magnetosomes and leaching of unbound enzymes while washing. The results indicate that the process of coupling the magnetosomes with the enzymes needs to be improved for attaining enhanced activity.

中文翻译：

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固定化酶对细菌磁小体的效率

摘要

尽管酶固定化取得了进步，改进的固定化技术和新的支持材料来源仍然是必要的。在这项工作中，我们将不同的酶，如 α-淀粉酶、α-葡萄糖苷酶、脂肪酶和过氧化氢酶固定在从趋磁细菌 (MTB) 中提取的细菌磁小体上。在四种酶中，与游离酶相比，过氧化氢酶和脂肪酶的酶活性显着增加，而另外两种酶的活性降低。发现游离过氧化氢酶活性为 300.9 U/mg，而发现固定化过氧化氢酶活性为 534.0 U/mg。与游离酶相比，固定化后的酶活性增加了 33.5%。在与脂肪酶活性的分光光度研究p与游离酶相比，-硝基苯乙酸酯作为底物的固定化脂肪酶活性增加了 2-5%。然而，与游离酶相比，磁小体固定化 α-葡萄糖苷酶和 α-淀粉酶的活性分别降低了 6% 和 20%。活性的下降可能是由于酶与磁小体的偶联不足以及洗涤时未结合的酶的浸出。结果表明需要改进将磁小体与酶偶联的过程以获得增强的活性。