Enhanced Biodegradation of Lignin by Laccase through HOBT Mediator: Mechanistic Studies Supported by FTIR and GCMS Studies
Enhanced Biodegradation of Lignin by Laccase through HOBT Mediator: Mechanistic Studies Supported by FTIR and GCMS Studies
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漆酶通过 HOBT 介体增强木质素的生物降解：FTIR 和 GCMS 研究支持的机理研究
DOI：
10.1007/s40710-017-0209-z
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
R. C. Panda
中科院分区：
文献类型：
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作者：
T. Senthilvelan;J. Kanagaraj;R. C. Panda
在本研究中，尝试了一种合适的漆酶生物降解木质素的工艺，并辅以介体1-羟基苯并三氮唑(HOBT)促进木质素的降解。结果表明，不同浓度的漆酶在pH值为7.0、温度为32℃、反应时间为24小时的条件下，木质素的生物降解率可达91-98%，最佳工艺参数为5.0 mM HOBT，UV分析证实原峰消失，表明木质素的芳香族含量分解为较小的组分。热重和差示扫描量热仪(TGA-DSC)分析表明，该化合物在137、257、417、586、699和759℃六个步骤分解时的热稳定性，最终残留量约为46%。差示扫描量热法测定的热变性起始温度为83.83℃。傅里叶变换红外光谱分析检测到羟基的存在(在2939-3420 cm−1)，C=C，C-H，C-N和C-S伸缩在150 5-1595 cm−1,1212 cm−1,2597-3272 cm−1，表明降解过程中存在酚酸和羧酸基团。气相色谱-质谱仪(GCMS)证实了各种中间体的形成。化学需氧量(COD)和总有机碳(TOC)分别降低了84%和80%。本研究对木质素废水的处理具有一定的参考价值。
In the present investigation, a suitable technology for biodegradation of lignin using laccase with the help of mediator 1-hydroxybenzotriazole (HOBT) for enhancing the degradation has been attempted. The results showed that biodegradation of lignin at the level of 91–98% could be achieved for different concentrations of laccase with optimized parameters of 5.0 mM HOBT at pH 7.0 and temperature at 32°C within 24 h. UV analysis confirmed the disappearance of the original peak indicating the break-down of aromatic content of lignin to smaller components. Thermo-gravimetric and differential scanning calorimetric (TGA-DSC) analysis showed thermal stability of the compound while decomposing through six steps, at 137, 257, 417, 586, 699 and 759°C, leaving a final residue of about 46%. The DSC experiment recorded the starting of thermal denaturing temperature as 83.83°C. Results of Fourier transform infrared (FTIR) analysis detected the presence of hydroxyl group (at 2939–3420 cm−1), C=C, C-H, C-N and C-S stretching at 1505–1595 cm−1, 1212 cm−1, 2597–3272 cm−1, indicating presence of phenolic and carboxylic acid groups during degradation. Gas Chromatography Mass Spectrometry (GCMS) confirmed the formation of various intermediates. Reduction of chemical oxygen demand (COD) and total organic carbon (TOC) at the level of 84 and 80% were observed, respectively. The present investigation is very useful in treating wastewater containing lignin.