Robles-Machuca Marcela, Aviles-Mejía Lucero, Romero-Soto Itzel Celeste, Rodríguez Jorge A, Armenta-Pérez Vicente Paúl, Camacho-Ruiz María Angeles
Tecnología de Alimentos, Secretaría de Investigación y Posgrado, Universidad Autónoma de Nayarit, Tepic, 63000, Nayarit, Mexico.
Laboratorio de Investigación en Biotecnología, Centro Universitario del Norte, Universidad de Guadalajara, Colotlán, 46200, Jalisco, Mexico.
Heliyon. 2023 Oct 14;9(10):e21006. doi: 10.1016/j.heliyon.2023.e21006. eCollection 2023 Oct.
Lignin, a complex heteropolymer present in plant cell walls, is now recognized as a valuable renewable resource with potential applications in various industries. The lignin biorefinery concept, which aims to convert lignin into value-added products, has gained significant attention in recent years. β-etherases, enzymes that selectively cleave β--4 aryl ether bonds in lignin, have shown promise in lignin depolymerization. In this study, the β-etherase LigF from sp. B11 was cloned, expressed, purified, and biochemically characterized. The LigF-AB11 enzyme exhibited optimal activity at 32 °C and pH 8.5 when catalyzing the substrate PNP-AV. The enzyme displayed mesophilic behavior and demonstrated higher activity at moderate temperatures. Stability analysis revealed that LigF-AB11 was not thermostable, with a complete loss of activity at 60 °C within an hour. Moreover, LigF-AB11 exhibited excellent pH stability, retaining over 50 % of its activity after 1 h under pH conditions ranging from 3.0 to 11.0. Metal ions and surface impregnation agents were found to affect the enzyme's activity, highlighting the importance of considering these factors in enzymatic processes for lignin depolymerization. This study provides valuable insights into the biochemical properties of LigF-AB11 and contributes to the development of efficient enzymatic processes for lignin biorefineries. Further optimization and understanding of β-etherases will facilitate their practical application in the valorization of lignin.
木质素是一种存在于植物细胞壁中的复杂杂聚物，如今被认为是一种具有潜在应用价值的可再生资源，在各个行业都有潜在应用。旨在将木质素转化为增值产品的木质素生物精炼概念近年来受到了广泛关注。β-醚酶是一类能选择性切割木质素中β-4芳基醚键的酶，在木质素解聚方面显示出了潜力。在本研究中，克隆、表达、纯化并对来自菌株B11的β-醚酶LigF进行了生化特性分析。LigF-AB11酶在催化底物对硝基苯-香草醛（PNP-AV）时，在32℃和pH 8.5条件下表现出最佳活性。该酶表现出嗜温特性，在中等温度下活性更高。稳定性分析表明，LigF-AB11不耐热，在60℃下1小时内活性完全丧失。此外，LigF-AB11表现出优异的pH稳定性，在pH值为3.0至11.0的条件下处理1小时后仍保留超过50%的活性。发现金属离子和表面浸渍剂会影响该酶的活性，这突出了在木质素解聚酶促过程中考虑这些因素的重要性。本研究为LigF-AB11的生化特性提供了有价值的见解，并有助于开发高效的木质素生物精炼酶促工艺。对β-醚酶的进一步优化和了解将促进其在木质素增值利用中的实际应用。
