Vargas-Ordóñez Antonio, Aguilar-Romero Inés, Villaverde Jaime, Madrid Fernando, Morillo Esmeralda
Institute of Natural Resources and Agrobiology of Seville, Spanish National Research Council (IRNAS-CSIC), 41012 Seville, Spain.
Microorganisms. 2023 Jan 12;11(1):196. doi: 10.3390/microorganisms11010196.
Paracetamol is one of the most used pharmaceuticals worldwide, but due to its widespread use it is detected in various environmental matrices, such as surface and ground waters, sediments, soils or even plants, where it is introduced mainly from the discharge of wastewater and the use of sewage sludge as fertilizer in agriculture. Its accumulation in certain organisms can induce reproductive, neurotoxic or endocrine disorders, being therefore considered an emerging pollutant. This study reports on the isolation, from sewage sludge produced in wastewater treatment plants (WWTPs), of bacterial strains capable of degrading paracetamol. Up to 17 bacterial strains were isolated, but only two of them, identified as CSW02 and CSW01, were able to degrade very high concentrations of paracetamol in solution as a sole carbon and energy source, and none of them had been previously described as paracetamol degraders. These bacteria showed the ability to degrade up to 500 mg L of paracetamol in only 6 and 4 h, respectively, much quicker than any other paracetamol-degrader strain described in the literature. The two main paracetamol metabolites, 4-aminophenol and hydroquinone, which present high toxicity, were detected during the degradation process, although they disappeared very quickly for paracetamol concentrations up to 500 mg L. The IC of paracetamol for the growth of these two isolates was also calculated, indicating that CSW01 was more tolerant than CSW02 to high concentrations of paracetamol and/or its metabolites in solution, and this is the reason for the much lower paracetamol degradation by CSW02 at 2000-3000 mg L. These findings indicate that both bacteria are very promising candidates for their use in paracetamol bioremediation in water and sewage sludge.
对乙酰氨基酚是全球使用最广泛的药物之一，但由于其广泛使用，在各种环境基质中都能检测到它，如地表水、地下水、沉积物、土壤甚至植物，它主要通过废水排放以及农业中使用污水污泥作为肥料进入这些环境。它在某些生物体内的积累会导致生殖、神经毒性或内分泌紊乱，因此被视为一种新兴污染物。本研究报告了从污水处理厂（WWTPs）产生的污水污泥中分离出能够降解对乙酰氨基酚的细菌菌株。共分离出多达17株细菌菌株，但其中只有两株，分别鉴定为CSW02和CSW01，能够在溶液中以对乙酰氨基酚作为唯一碳源和能源降解非常高的浓度，且此前没有任何一株被描述为对乙酰氨基酚降解菌。这些细菌分别能够在仅6小时和4小时内降解高达500毫克/升的对乙酰氨基酚，比文献中描述的任何其他对乙酰氨基酚降解菌株都要快得多。在降解过程中检测到了两种主要的对乙酰氨基酚代谢产物，4-氨基苯酚和对苯二酚，它们具有高毒性，不过对于浓度高达500毫克/升的对乙酰氨基酚，它们很快就消失了。还计算了对乙酰氨基酚对这两种分离菌株生长的抑制浓度（IC），表明CSW01比CSW02对溶液中高浓度的对乙酰氨基酚及其代谢产物更具耐受性，这就是CSW02在2000 - 3000毫克/升时对乙酰氨基酚降解率低得多的原因。这些发现表明，这两种细菌在水和污水污泥中对乙酰氨基酚生物修复方面都是非常有前景的候选菌株。
