Color and toxicity removal following tyrosinase-catalyzed oxidation of phenols
Color and toxicity removal following tyrosinase-catalyzed oxidation of phenols
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DOI：
10.1021/bp0000510
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发表时间：
2000-07-01
影响因子：
2.9
通讯作者：
Nicell, JA
中科院分区：
文献类型：
--
作者：
Ikehata, K;Nicell, JA
根据蘑菇酪氨酸酶（多酚氧化酶，EC 1.14.18.1）催化的苯酚氧化产物的残留颜色和毒性来评估它们。硫酸铝的加入对酪氨酸酶处理的苯酚溶液中有色产物的去除影响不大。尽管当在反应开始之前或反应完成之后添加时，壳聚糖成功地用于去除颜色，但是当在反应之后添加时，壳聚糖的所需剂量较低。在这种情况下，实现90%脱色所需的壳聚糖的最小剂量与苯酚初始浓度的对数成比例。壳聚糖的颜色去除诱导除了似乎是化学相互作用的结果，其次是混凝机制。除2，4-二氯苯酚外，苯酚和氯苯酚的所有处理溶液的毒性均显著低于其相应的初始毒性，如使用Microtox测定所测量的。壳聚糖的加入显著增强了毒性的降低。用酪氨酸酶处理的苯酚溶液的毒性明显低于先前报道的用过氧化物酶处理的溶液的毒性。
The products of phenol oxidation catalyzed by mushroom tyrosinase (polyphenol oxidase, EC 1.14.18.1) were assessed in terms of their residual color and toxicity. The addition of aluminum sulfate had little effect on the removal of colored products from phenol solutions treated with tyrosinase. Although chitosan was used successfully to remove the color when added before the reaction initiation or after the reaction completion, the required dose of chitosan was lower when it was added after the reaction. In this case, the minimum doses of chitosan required to achieve 90% color removal were proportional to the logarithm of the initial concentration of phenol. The color removal induced by chitosan addition appeared to be the result of chemical interaction followed by a coagulation mechanism. All treated solutions of phenol and chlorophenols, except 2,4-dichlorophenol, had substantially lower toxicities than their corresponding initial toxicities, as measured using the Microtox assay. Chitosan addition significantly enhanced the reduction in toxicity. The toxicities of the phenol solutions treated with tyrosinase were markedly lower than previously reported toxicities of solutions treated with peroxidase enzymes.