Beijing Engineering Research Center of Environmental Material for Water Purification, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry，Beijing Technology and Business University，Beijing 100048，China.
Chemosphere. 2023 Nov;340:139792. doi: 10.1016/j.chemosphere.2023.139792. Epub 2023 Aug 12.
Chlortetracycline (CTC), a widely used typical tetracycline antibiotic, has raised increasing concerns due to its potential health and environmental risks. Biodegradation is considered an effective method to reduce CTC in environment. In this study, a strain Aspergillus sp. LS-1, which can efficiently degrade CTC, was isolated from CTC-rich activated sludge. Under optimal conditions, the maximum removal efficiency of CTC could reach 95.41%. Temperature was the most significant factor affecting the degradation efficiency of LS-1. The 19 products were identified in the CTC degradation by strain LS-1, and three degradation pathways were proposed. All the degradation pathways for CTC exhibited ring-cleaving, which may accelerate the mineralization of CTC. To gain more comprehensive insights into this strain, we obtained the genome of LS-1, which had high GC content (50.1%) and completeness (99.3%). The gene annotation revealed that LS-1 contains some vital enzymes and resistance genes that may carry functional genes involved in the CTC degradation. In addition, other antibiotic resistance genes were found in the genome of LS-1, indicating that LS-1 has the potential to degrade other antibiotics. This study provides a more theoretical basis for the investigation of CTC degradation by fungi and new insights into the biodegradation of CTC.
金霉素（CTC）是一种广泛使用的典型四环素类抗生素，由于其潜在的健康和环境风险而引起了越来越多的关注。生物降解被认为是减少环境中 CTC 的有效方法。本研究从富含 CTC 的活性污泥中分离出一株可有效降解 CTC 的曲霉属（Aspergillus sp.）LS-1 菌株。在最佳条件下，CTC 的最大去除效率可达 95.41%。温度是影响 LS-1 降解效率的最显著因素。通过菌株 LS-1 降解 CTC 鉴定出 19 种产物，并提出了三种降解途径。所有 CTC 的降解途径均表现出环开裂，这可能加速 CTC 的矿化。为了更全面地了解该菌株，我们获得了 LS-1 的基因组，其 GC 含量（50.1%）高，完整性（99.3%）高。基因注释表明 LS-1 含有一些重要的酶和抗性基因，这些基因可能携带与 CTC 降解有关的功能基因。此外，在 LS-1 的基因组中还发现了其他抗生素抗性基因，表明 LS-1 具有降解其他抗生素的潜力。本研究为真菌降解 CTC 的研究提供了更理论的基础，并为 CTC 的生物降解提供了新的见解。
