School of Environment and Natural Resources, Doon University, Dehradun, Uttarakhand, 248012, India.
School of Environment and Natural Resources, Doon University, Dehradun, Uttarakhand, 248012, India; School of Biological Sciences, Doon University, Dehradun, Uttarakhand, 248012, India.
Chemosphere. 2022 Jun;297:134126. doi: 10.1016/j.chemosphere.2022.134126. Epub 2022 Mar 2.
In this study, decolorization and degradation of malachite green dye was studied using the laccase immobilized pine needle biochar. Successful immobilization of biochar was achieved by adsorption and confirmed through scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX), Fourier transform infrared spectroscopy (FTIR). High laccase binding of 64.4 U/g and high immobilization yield of 78.1% was achieved using 4U of enzyme at pH3 and temperature 30 °C. The immobilized laccase retained >50% relative activity in the pH range 2-7, >45% relative activity at 65 °C and >55% relative activity at 4 °C for 4 weeks. The re-usability of immobilized enzyme was checked with 2, 2'-azino-bis 3-ethylbenzothiazoline-6-sulphonic acid (ABTS) substrate and enzyme retained 53% of its activity after 6 cycles. Immobilized laccase was used for the degradation and decolorization of azo dye malachite green in aqueous solution. More than 85% removal of malachite green dye (50 mg/L) was observed within 5 h. FTIR and high performance liquid chromatography (HPLC) analysis clearly indicated the breakdown of dye and presence of metabolites (leuco malachite green, methanone, [4-(dimethyl amino)pheny]phenyl and 3-dimethyl-phenyl amine) in gas chromatography-mass spectrometry (GC-MS) analysis confirmed the dye degradation. Phytotoxicity analysis indicated that the enzymatic degradation resulted in lesser toxic metabolites than the original dye. Thus, laccase immobilized biochar can be used as an efficient biocatalytic agent to remove dye from water.
在这项研究中，使用固定化于松针生物炭的漆酶对孔雀石绿染料进行了脱色和降解研究。通过扫描电子显微镜和能量色散 X 射线分析（SEM-EDX）、傅里叶变换红外光谱（FTIR）证实了生物炭的成功固定化。在 pH3 和温度 30°C 下，使用 4U 酶可实现 64.4 U/g 的高漆酶结合量和 78.1%的高固定化产率。固定化漆酶在 pH 2-7 范围内保留了>50%的相对活性，在 65°C 下保留了>45%的相对活性，在 4°C 下保留了>55%的相对活性，持续 4 周。使用 2,2'-联氮-双（3-乙基苯并噻唑啉-6-磺酸）（ABTS）底物检查了固定化酶的可重复使用性，酶在 6 个循环后保留了其 53%的活性。固定化漆酶用于在水溶液中降解偶氮染料孔雀石绿。在 5 小时内观察到超过 85%的孔雀石绿染料（50mg/L）去除。傅里叶变换红外光谱和高效液相色谱（HPLC）分析清楚地表明染料的分解和存在代谢物（隐色孔雀石绿、甲酮、[4-（二甲基氨基）苯基]苯基和 3-二甲基-苯胺）在气相色谱-质谱（GC-MS）分析中证实了染料的降解。植物毒性分析表明，酶促降解导致比原始染料更少的有毒代谢物。因此，固定化漆酶的生物炭可作为一种有效的生物催化剂，用于从水中去除染料。
