Degradation of xenobiotic compounds and dehalogenation by using multi enzyme systems of a newly isolated fungus, Geotrichum canididum Dec 1

(1)对硫酸盐纸浆漂白废水进行脱色处理，脱色率可达70-80%。12月1日之前的脱色过程由两个步骤组成，即第一步有色物质吸附到细胞表面，第二步由细胞生物降解。同时，含有卤素的芳香族化合物对应的可吸附有机卤素(AOX)减少了43%，表明Dec 1进行了与出水中木质素脱色并行的脱卤化。(2)氧气脱木素工艺的出水在Dec 1进行脱色，脱色率达到90%。采用12月1日发酵液对氧脱木素浆进行生物浸出，纸浆白度提高30个点，卡伯值降低10个点。废水在12月1日前脱色后，与纸浆混合，继续漂白。随着纸浆白度的增加，…更重要的是，Dec 1显示了连续处理废水和漂白纸浆的潜力。(3)用Dec 1的培养物对未漂白的硫酸盐纸浆进行了漂白试验，白度的提高和卡伯值的降低几乎与已有研究的担子菌相当或更多。未漂白的硫酸盐在12月1日前漂白后，将纸浆洗涤并与新鲜生长的12月1日培养物混合，继续进行第二次漂白。(4)从12月1日的发酵液中提纯了过氧化物酶(DyP)和锰过氧化物酶(MNP)。在氧脱木素废水脱色、氧脱木素纸浆漂白和未漂白硫酸盐浆漂白过程中检测到DyP和MNP的活性，发现这两种酶在这些反应中起着重要的作用。通过平板试验和商品木质素的液体培养，证实了菌株Dec-1对木质素的降解能力。在平板试验中，木质素的颜色由棕色变为黄色。凝胶层析法证实，木质素的平均分子质量由原来的8万降到了3000以下。随着DyP和MNP活性的测定，这是首次发现担子菌以外的两种参与木质素降解的酶的存在。阐明了这两种酶对Poly R-478染料的降解情况。较少

(1) The effluent from kraft pulp bleaching process was decolorized by G. canididum Dec 1 and the color removal ratio reached 70-80%. The decolorization process by Dec 1 consists of two steps, namely the first adsorption of color substances to the surface of the cells and the second biodegradation by the cells. Simultaneously, the absorbable organic halogens (AOX) that correspond to the aromatic compounds containing halogen was reduced by 43%, indicating that Dec 1 conducted dehalogenation in parallel to decolorization of lignin in the effluent.(2) The effluent from oxygen-delignified process was decolorized by Dec 1 and the color removal ratio reached 90%. Bioleaching of oxygen-delignified pulp was carried out by the culture broth of Dec 1 and the brightness of the pulp increased 30 points and the kappa number decreased by 10 points. After the effluent was decolorized by Dec 1, the effluent was mixed with the pulp and the bleaching was continued. As the brightness of the pulp increased … More significantly, Dec 1 showed potential of consecutive treatment of the effluent and the bleaching of the pulp.(3) Bleaching of unbleached kraft pulp was tried by using the culture of Dec 1. The increase in brightness and the reduction of the kappa number were almost equivalent to or more than those of well-studied basidiomycetes. After the unbleached kraft was bleached by Dec 1, the pulp was washed and mixed with the freshly grown Dec 1 culture and the second bleaching was continued. The increase in brightness reached 50 points and this values demonstrate the usefulness of the bio-bleaching of the pulp by Dec 1.(4) Peroxidase (DyP) and manganese peroxidase (MnP) were purified from the culture broth of Dec 1. As the activities of DyP an MnP were detected during decolorization of oxygen-delignified effluent, bleaching of oxygen-delignified pulp and bleaching of unbleached kraft pulp, the two enzymes are found to be heavily involved in those reactions. The higher activity of MnP in the degradation of lignin was newly found.(5) Lignin-degradation ability of Dec 1 was confirmed by the plate test and by the liquid culture using commercial lignin. The color of lignin changed from brown to yellow in plate test. It was confirmed by gel chromatography that the average molecular mass of the original lignin, 80,000 was reduced to less than 3,000. As the activities of DyP and MnP were detected, this is the first report that the existence of two enzymes involved in lignin degradation was found other than basidiomycetes. The degradation of the dye, Poly R-478 by the two enzymes was also clarified. Less