Studies on the degradation of butyltin and phenyltin compounds in various laccase-mediatorsystems

• Main Authors: Liu, Jun-You, 劉俊佑
• Other Authors: Liu, Shiu-Mei
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/gn8r7g

碩士 === 國立臺灣海洋大學 === 海洋生物研究所 === 105 === Organotin compounds are widely used for insecticide, fungicide and anti-fouling paint. They have been released and detected in various environments . To remove these pollutants or contaminants from environments, wastewater treatment plants had been developed to convert wastewater into an effluent that can be returned to the water cycle. In most wastewater treatment plants, coarse solids and other large materials were removed by filtration and sedimentation. The residual organics and suspended solids were further removed by chemical and biological treatments. However, some contaminants such as heavy metal contaminants require further ion exchange or electrolysis, or some of the effluent with high levels of protein and fat and low biodegradability, must be treated with enzymes, so some contaminants are subject to special method to remove. White rot fungi and some mushrooms produce lignindegrading enzymes – laccase, these enzymes due to their low specificity, there have been many reports in the past that are used to carry out some of the degradation of pollutants by these enzymes. Enzymatic treatment of wastewater is a choice. The broad substrate specificity of laccases makes these enzymes a promising candidate for diverse industrial applications. In this study, degradation of tetrabutyltin (4 ppm) and tetraphenyltin (4 ppm) by laccase isolated from the white rot fungi Perennipora tephropora TFRI707, and the mushrooms Agrocybe aegerita and Pleurotus geesteranus were investigated. Laccase of Perennipora tephropora TFRI707 (6025.7 U/mL) was obtained from the extracellular fluid after seventeen days in the semi-solid culture with the bark of paper mulberry. Laccase of Agrocybe aegerita and Pleurotus geesteranus (1748.6 U/mL and 811.4 U/mL. respectively) were extracted from the spent of mushrooms. Laccase from Perennipora tephropora TFRI707 removed 83.9-87.4% of tetrabutyltin and 78.0-91.9% tetrephenyltin; laccase from Agrocybe aegerita removed 73.7-88.9% of tetrabutyltin and 75.5-92.0% of tetraphenyltin; laccase from Pleurotus geesteranus removed 70.4-85.3% of tetrabutyltin and 72.9-90.2% of tetrephenyltin after seven days incubation when added with and without mediators (ABTS, violuric acid, 4-hydroxyacetophenone, and syringaldehyde). Tetrabutyltin, dibutyltin, and monobutyltin were detected during the degradation of tetrabutyltin. Triphenyltin, diphenyltin, and monophenyltin were detected during the degradation of tetraphenyltin. Therefore, the oxidative enzyme can effectively and rapidly degradeorganotin heavy metals, but the practical utilization in the environment needs to be further explored.