Driessel B V, Christov L
Sappi Biotechnology Laboratory, Department of Microbiology and Biochemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa.
J Biosci Bioeng. 2001;92(3):271-6. doi: 10.1263/jbb.92.271.
Bleach plant effluents from the pulp and paper industry generated during bleaching with chlorine-containing chemicals are highly colored and also partly toxic due to the presence of chloro-organics, hence the need for pretreatment prior to discharge. In a rotating biological contactor (RBC) reactor effluent decolorization was studied using Coriolus versicolor, a white-rot fungus and Rhizomucor pusillus strain RM7, a mucoralean fungus. Decolorization by both fungi was directly proportional to initial color intensities. It was found that the extent of decolorization was not adversely affected by color intensity, except at the lowest level tested. It was shown that decolorization of 53 to 73% could be attained using a hydraulic retention time of 23 h. With R. pusillus, 55% of AOX were removed compared to 40% by C. versicolor. Fungal treatment with both R. pusillus and C. versicolor rendered the effluent essentially nontoxic. Addition of glucose to decolorization media stimulated color removal by C. versicolor, but not with R. pusillus. Ligninolytic enzymes (manganese peroxidase and laccase) were only detected in effluent treated by C. versicolor. It seems that there are definite differences in the decoloring mechanisms between the white-rot fungus (adsorption + biodegradation) and the mucoralean fungus (adsorption). This aspect needs to be investigated in greater detail to verify the mode responsible for the decolorization activity in both types of fungi.
纸浆和造纸工业在使用含氯化学品漂白过程中产生的漂白厂废水颜色很深，并且由于氯代有机物的存在而具有一定毒性，因此在排放前需要进行预处理。在旋转生物接触器（RBC）反应器中，使用白腐真菌云芝和毛霉目真菌微小根毛霉RM7菌株研究了废水脱色情况。两种真菌的脱色率均与初始颜色强度成正比。结果发现，除了在测试的最低颜色强度水平外，脱色程度不受颜色强度的不利影响。结果表明，水力停留时间为23小时时，脱色率可达53%至73%。对于微小根毛霉，AOX（可吸附有机卤化物）的去除率为55%，而云芝的去除率为40%。微小根毛霉和云芝的真菌处理均使废水基本无毒。向脱色培养基中添加葡萄糖可促进云芝的脱色，但对微小根毛霉无效。木质素分解酶（锰过氧化物酶和漆酶）仅在云芝处理的废水中检测到。白腐真菌（吸附+生物降解）和毛霉目真菌（吸附）的脱色机制似乎存在明显差异。这方面需要更详细地研究，以验证两种真菌中负责脱色活性的模式。
