排序方式: 共有12条查询结果,搜索用时 15 毫秒
11.
Calcium-alginate pectin entrapped bitter gourd peroxidase (BGP) has been employed for the treatment of disperse dyes: Disperse
Brown 1 (DB 1) and Disperse Red 17 (DR 17). Peroxidase alone was unable to decolorize DR 17 and DB 1. However, the investigated
dyes were decolorized maximally by BGP in the presence of 0.2 mmol/L redox mediator, violuric acid (VA). A slow decrease in percent
decolorization was observed when VA concentration was higher than 0.2 mmol/L which could likely be due to the high reactivity of its
aminoxyl radical (> N–O.) intermediate, that might undergo chemical reactions with aromatic amino acid side chains of the enzyme
thereby inactivating it. Maximum decolorization of the dyes was observed at pH 3.0 and 40°C within 2 hr of incubation. Immobilized
peroxidase decolorized 98% DR 17 and 71% DB 1 using 35 U of BGP in batch process in 90 min. Immobilized enzyme decolorized
85% DR 17 and 51% DB 1 whereas soluble enzyme decolorized DR 17 to 48% and DB 1 to 30% at 60°C. UV-visible spectral analysis
was used to evaluate the degradation of these dyes and their toxicity was tested by Allium cepa test. The generally observed higher
stability of the bioaffinity bound enzymes against various forms of inactivation may be related to the specific and strong binding of
enzyme with bioaffinity support which prevents the unfolding/denaturation of enzyme. Thus entrapped peroxidase was found to be
effective in the decolorization of the investigated dyes. 相似文献
12.
The chemical composition of pectin production wastewater and its toxicity during biological treatment were investigated. Samples
of wastewater from di erent steps of a pectin production wastewater biological treatment plant were investigated including the influent
of the treatment (1), after denitrification tank (2), after anaerobic treatment (3) and final e uent (4). The conventional physicochemical
characteristics of samples did not indicate wastewater toxicity. However, toxicity assessments carried out on Vibrio fischeri and
Scenedesmus subspicatus indicated low EC50 values. The fractionation of the samples using an XAD resin showed that the toxicity was
associated with the organic matter. Wastewater apparent molecular mass distributions were 14.3, 25.0, 24.4 and 29.6 kDa for samples
1–4, respectively. Finally, characteristics of the sample by pyrolisis-gas chromatography-mass spectrometry (Py-CG-MS) demonstrated
its polyphenolic nature and a 23% increase in the levels of such compounds after the first biological treatment step. 相似文献