Degradation of ionic liquids by UV/H2O2 process and CMCase from novel ionic liquid-tolerant alkaliphilic Nocardiopsis sp. SSC4
Degradation of ionic liquids by UV/H2O2 process and CMCase from novel ionic liquid-tolerant alkaliphilic Nocardiopsis sp. SSC4
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通过 UV/H2O2 工艺和 CMCase 降解新型耐碱性诺卡氏菌属中的离子液体。
DOI：
10.1080/13102818.2017.1335613
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发表时间：
2017
影响因子：
1.4
通讯作者：
Noriaki Kishimoto.
中科院分区：
文献类型：
--
作者：
Atsushi Kurata;Shota Shimizu;Yutaro Shiraishi;Mihoko Abe;Nobutoshi Naito;Mihoko Shimada;Noriaki Kishimoto.
我们证明了两种离子液体（1-丁基-3-甲基咪唑氯化物，[BMIM]Cl，和1-乙基吡啶溴化物，[EtPy]Br），这是有用的木材组分的溶解的降解。通过薄层色谱法（TLC）和电喷雾电离-质谱法（ESI-MS）检测[BMIM]+和[EtPy]+。[BMIM]+比[EtPy]+更难降解。用0.2%（v/v）H2 O2紫外光照射16 h降解1 mmol/L [BMIM]+，而单独紫外光照射降解1 mmol/L [EtPy]+。此外，我们还分离到一株耐离子液体的嗜碱放线菌，诺卡氏菌。SSC 4。菌株SSC 4在1.0%（v/v，48.1mmol/L）1-乙基-3-甲基咪唑三氟甲磺酸盐（[EMIM] CF 3SO 3）存在下产生羧甲基纤维素酶（CMCase），该酶可用于从木材中提取富含纤维素的物质。在菌株SSC 4的情况下，CMCase由大于0.5%的CMC诱导合成。添加0%~ 1.0%胰蛋白胨或0%~ 2.0%酵母膏均能降低CMCase的活性，且呈浓度依赖性。在37 °C下用1.0%（w/v）CMC培养基（pH 9.0）培养菌株SSC 4 48 h后，培养上清液显示出0.03 U/mg的CMC酶活性。CMCase的最佳反应温度为45 °C。CMCase在高达37 °C下孵育20小时是稳定的。[EMIM] CF_3SO_3存在下[BMIM]~+和[EtPy]~+的降解特性以及CMCase的活性，为生物质资源的生物转化系统的开发提供了有益的参考。
We demonstrated the degradation of two ionic liquids (1-butyl-3-methylimidazolium chloride, [BMIM]Cl, and 1-ethylpyridinium bromide, [EtPy]Br) that are useful for the solubilization of wood components. [BMIM]+and [EtPy]+were detected by thin-layer chromatography (TLC) and electrospray ionization–mass spectrometry (ESI-MS). [BMIM]+was harder to degrade than [EtPy]+. Ultraviolet (UV) irradiation with 0.2% (v/v) H2O2for 16 h degraded 1 mmol/L [BMIM]+, whereas UV irradiation alone degraded 1 mmol/L [EtPy]+. Additionally, we isolated an ionic liquid-tolerant alkaliphilic actinomycete,Nocardiopsissp. SSC4. Strain SSC4 produced carboxymethylcellulase (CMCase) in the presence of 1.0% (v/v, 48.1 mmol/L) 1-ethyl-3-methylimidazolium trifluoromethanesulphonate ([EMIM]CF3SO3), which is useful for the extraction of cellulose-rich materials from wood. In the case of strain SSC4, CMCase was inducibly synthesized by more than 0.5% CMC. The addition of 0%–1.0% tryptone or 0%–2.0% yeast extract decreased the CMCase activity in a concentration-dependent manner. After cultivation of strain SSC4 with 1.0% (w/v) CMC medium (pH 9.0) for 48 h at 37 °C, the culture supernatant exhibited CMCase activity at 0.03 U/mg. The optimum reaction temperature of CMCase was 45 °C. CMCase was stable up to 37 °C for 20 h incubation. The degradation characteristics of [BMIM]+and [EtPy]+and the activity of CMCase in the presence of [EMIM]CF3SO3may be useful for the development of a bioconversion system for biomass resources.