Yu Dali, Liu Ying, Cai Hongying, Huang Wanqiu, Wu Huijun, Yang Peilong
Qilu Normal University, Jinan, Shandong, China.
Key Laboratory for Feed Biotechnology of the Ministry of Agriculture and Rural Affairs, National Engineering Research Center of Biological Feed, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China.
PeerJ. 2025 Apr 28;13:e19327. doi: 10.7717/peerj.19327. eCollection 2025.
Bacterial laccases play a crucial role in the degradation of lignin and the turnover of soil organic matter. Their advantageous properties make them highly suitable for a wide range of industrial applications. However, the limited identification of these potential enzymes has impeded their full utilization. The straw-amended soil provides materials for the development of bacterial laccases.
Metagenomic sequencing of a straw-amended soil was conducted to explore novel bacterial laccases. The putative bacterial laccases were then screened using profile hidden Markov models for further analysis. The most abundant gene, , was heterologously expressed in and the recombinant laccase was purified for enzymatic characterization.
A total of 322 putative bacterial laccases were identified in the straw-amended soil. Among them, 45 sequences had less than 30% identity to any entries in the Carbohydrate-Active Enzyme database and only 4.66% were more than 75% similar to proteins in the NCBI environmental database, exhibiting their novelty. These enzymes were found across various bacterial orders, demonstrating substantial diversity. Phylogenetic analysis revealed a number of the bacterial laccase sequences clustered with homologs characterized by favorable enzymatic properties. Five full-length representative bacterial laccase genes were obtained by modified thermal asymmetric interlaced PCR. The laccase activity of lacS1 was validated. It was a mesophilic enzyme with alkaline stability and halotolerance, indicating its promise for industrial applications.
These findings highlight novel bacterial laccase resources with potential for industrial applications and enzyme engineering.
细菌漆酶在木质素降解和土壤有机质周转中起着关键作用。其有利特性使其非常适合广泛的工业应用。然而，这些潜在酶的鉴定有限阻碍了它们的充分利用。添加秸秆的土壤为细菌漆酶的开发提供了材料。
对添加秸秆的土壤进行宏基因组测序以探索新型细菌漆酶。然后使用轮廓隐马尔可夫模型筛选推定的细菌漆酶以进行进一步分析。最丰富的基因在中进行异源表达，并纯化重组漆酶进行酶学表征。
在添加秸秆的土壤中总共鉴定出322种推定的细菌漆酶。其中，45个序列与碳水化合物活性酶数据库中的任何条目具有不到30%的同一性，只有4.66%与NCBI环境数据库中的蛋白质相似度超过75%，显示出它们的新颖性。这些酶存在于各种细菌目中，表现出丰富的多样性。系统发育分析表明，许多细菌漆酶序列与具有良好酶学特性的同源物聚集在一起。通过改良的热不对称交错PCR获得了五个全长代表性细菌漆酶基因。验证了lacS1的漆酶活性。它是一种具有碱性稳定性和耐盐性的嗜温酶，表明其在工业应用中的潜力。
这些发现突出了具有工业应用和酶工程潜力的新型细菌漆酶资源。
