Gaur Nisha, Narasimhulu Korrapati, Y Pydisetty
Department of Biotechnology, National Institute of Technology Warangal 506004 Telangana India
Department of Chemical Engineering, National Institute of Technology Warangal 506004 Telangana India.
RSC Adv. 2018 Apr 20;8(27):15044-15055. doi: 10.1039/c8ra01204k. eCollection 2018 Apr 18.
Laccase (lac) and manganese peroxidase (MnP) enzymes from the novel isolates, grown on lignin basic media (LBM) were purified by 80% ammonium sulphate fractionation, dialysis and DEAE-sepharose column chromatography. The optimum temperatures for laccase production were 60 °C, 50 °C and 50 °C and for MnP production were 50 °C, 70 °C and 60 °C from NITW715076_2, NITW715076_1 and NITW715076 isolates, respectively. The optimal pH for production was found to be 5 for production of both the enzymes from all the isolates. 2.8-3.5 fold enzyme purification was achieved retaining around 60-70% of the initial activity. SDS-PAGE revealed the molecular mass of laccase and MnP to be 66 kDa and 48 kDa, respectively. The substrate ABTS and MnSO exhibited more specificity towards NITW715075_2 derived laccase and MnP (lac: = 0.38 mM, = 71.42 U ml; MnP: = 0.17 mM, = 106.38 U ml) compared to NITW715076_1 (lac: = 3.97 mM, = 148.8 U ml; MnP: = 0.90 mM, = 114.67 U ml) and NITW715076 (lac: = 0.46 mM, = 23.42 U ml; MnP: = 0.19 mM, = 108.10 U ml) derived. l-Cysteine and sodium azide imposed a strong inhibitory effect on the activities of both the enzymes. EDTA inhibited laccase and MnP activity at higher concentration. SDS strongly inhibited activity while for MnP it showed less inhibitory effect. The enzymes were employed for ethanol production from rice and wheat bran biomass which showed 39.29% improved production compared to control. After evaluating the applicability of these enzymes it can be suggested that the ligninolytic enzyme of isolates could be effectively employed in enhanced ethanol production and could be explored for other putative applications.
在木质素基础培养基（LBM）上生长的新型菌株所产生的漆酶（lac）和锰过氧化物酶（MnP），通过80%硫酸铵分级沉淀、透析和DEAE-琼脂糖柱色谱法进行纯化。来自NITW715076_2、NITW715076_1和NITW715076菌株的漆酶产生的最适温度分别为60℃、50℃和50℃，锰过氧化物酶产生的最适温度分别为50℃、70℃和60℃。发现所有菌株产生这两种酶的最适pH均为5。实现了2.8 - 3.5倍的酶纯化，同时保留了约60 - 70%的初始活性。SDS-PAGE显示漆酶和锰过氧化物酶的分子量分别为66 kDa和48 kDa。与NITW715076_1（漆酶：Km = 3.97 mM，Vmax = 148.8 U/ml；锰过氧化物酶：Km = 0.90 mM，Vmax = 114.67 U/ml）和NITW715076（漆酶：Km = 0.46 mM，Vmax = 23.42 U/ml；锰过氧化物酶：Km = 0.19 mM，Vmax = 108.10 U/ml）相比，底物ABTS和MnSO对源自NITW715075_2的漆酶和锰过氧化物酶表现出更高的特异性（漆酶：Km = 0.38 mM，Vmax = 71.42 U/ml；锰过氧化物酶：Km = 0.17 mM，Vmax = 106.38 U/ml）。l-半胱氨酸和叠氮化钠对这两种酶的活性均有强烈抑制作用。EDTA在较高浓度下抑制漆酶和锰过氧化物酶的活性。SDS强烈抑制活性，而对锰过氧化物酶的抑制作用较小。这些酶被用于从米糠和麦麸生物质中生产乙醇，与对照相比，乙醇产量提高了39.29%。在评估了这些酶的适用性后，可以认为这些菌株的木质素分解酶可有效地用于提高乙醇产量，并可探索其其他潜在应用。
