Department of Biochemistry and Microbiology, Cook College, Rutgers University, New Brunswick, New Jersey 08903.
Appl Environ Microbiol. 1988 Jul;54(7):1719-23. doi: 10.1128/aem.54.7.1719-1723.1988.
Screening of leachable toxic chemicals in a horseradish peroxidase-H(2)O(2) immobilization system established that immobilization was promising for most phenolic pollutants but not for benzoic acid, 2,6-dinitrocresol, or dibutyl phthalate. The treatment did not mobilize inherently nonmobile pollutants such as anilines and benzo[a]pyrene. In a separate study, an extracellular laccase in the culture filtrate of Geotrichum candidum was selected from five fungal enzymes evaluated as a cost-effective substitute for horseradish peroxidase. This enzyme was used in demonstrating the immobilization and subsequent fate of C-labeled 4-methylphenol and 2,4-dichlorophenol in soil columns. When applied to Lakewood sand, 98.1% of 4-methylphenol was leached through with distilled water. Two days after immobilization treatment with the G. candidum culture filtrate, only 9.1% of the added 4-methylphenol was leached with the same volume of water. Of the more refractory test pollutant 2,4-dichlorophenol, 91.6% had leached at time zero and 48.5% had leached 1 day after the immobilization treatment. However, 2 weeks after immobilization, only 12.0% of the 2,4-dichlorophenol was leached compared with 61.7% from the control column that received no immobilization treatment. No remobilization of the bound pollutants was detected during 3- and 4-week incubation periods. Enzymatic immobilization of phenolic contaminants in soil appears to be a promising technique for the reduction of groundwater pollution by such substances.
辣根过氧化物酶-H2O2 固定化体系中可浸出有毒化学物质的筛选表明，固定化技术对大多数酚类污染物具有很好的应用前景，但对苯甲酸、2,6-二硝基间甲酚和邻苯二甲酸二丁酯则不然。该处理方法不会使苯胺和苯并[a]芘等固有不可移动的污染物移动。在另一项研究中，从评估的五种真菌酶中选择了出芽短梗霉培养液中的胞外漆酶作为辣根过氧化物酶的经济有效替代品。该酶用于示踪土壤柱中标记的 4-甲基苯酚和 2,4-二氯苯酚的固定化和随后的命运。当应用于莱克伍德砂时，98.1%的 4-甲基苯酚被蒸馏水淋洗出。用出芽短梗霉培养液进行固定化处理两天后，只有 9.1%的添加 4-甲基苯酚被相同体积的水淋洗出。对于更难处理的测试污染物 2,4-二氯苯酚，零时刻有 91.6%淋洗出，固定化处理后 1 天有 48.5%淋洗出。然而，固定化后 2 周，与未进行固定化处理的对照柱相比，只有 12.0%的 2,4-二氯苯酚被淋洗出，而对照柱中 61.7%的 2,4-二氯苯酚被淋洗出。在 3 至 4 周的孵育期间，未检测到结合污染物的再移动。酚类污染物在土壤中的酶固定化似乎是减少此类物质对地下水污染的一种很有前途的技术。
