摘要
      抗生素的通用性被认为是废水处理厂产生抗生素抗性基因（ARGs）的主要原因。然而，关于活性污泥生物合成抗生素的报道很少。在本研究中，使用宏基因组学和宏转录组学对两个污水处理厂的絮凝污泥和生物膜中抗生素生物合成基因（ABG）的分布和表达进行了破译。结果表明，2%的社区通常与抗生素生产有很好的联系，这表明WWTP的抗生素合成能力是不可忽视的。共检测到26种抗生素93个ABG，其中氨基糖苷类、β-内酰胺类、安沙霉素类、肽类、大环内酯类占多数。检测到的ABG的相对丰度有很大的区间，从0.000006%到0.042%。相对表达水平较高的合成基因的主要抗生素类型是单内酰胺类、青霉素和头孢菌素类以及链霉素，主要属于β-内酰胺类和氨基糖苷类。提出了链霉素合成、青霉素和头孢菌素合成的假设合成途径。从元组学数据来看，这两种抗生素的ABG和ARGs在活性污泥中的共存也很明显。这些发现首次证明了活性污泥中抗生素合成的潜力，揭示了污水处理厂中抗生素和耐药性基因的新来源，从而加剧了环境污染。
Abstract
The generic of antibiotics is considered to be a main reason for the generation of antibiotic resistance genes (ARGs) in wastewater treatment plants (WWTPs). However, little has been reported about the antibiotic biosynthesis by activated sludge. In this study, the distribution and expression of antibiotic biosynthetic genes (ABGs) in the floc sludge and biofilm from two WWTPs were deciphered using metagenomics and metatranscriptomics. The results showed that 2% of the community were in general well-linked to antibiotic production, indicating a non-negligible antibiotic synthetic ability of WWTPs. 93 ABGs belonging to 26 antibiotics were determined, among which aminoglycosides, β-lactams, ansamycins, peptides, macrolides were majority. The relative abundances of detected ABGs had a large interval, ranging from 0.000006% to 0.042%. The predominant antibiotic types of synthetic genes with higher relative expression levels were monobactams, penicillin & cephalosporins and streptomycin, primarily belonging to β-lactams and aminoglycosides. The hypothetical synthetic pathways of streptomycin synthesis and penicillin & cephalosporin synthesis were proposed. And the coexistence of ABGs and ARGs for these two antibiotics was also pronounced in activated sludge from meta-omics data. These findings for the first time demonstrated the antibiotic synthetic potential in activated sludges, revealing new sources of antibiotics and resistance genes in WWTPs, and thereby aggravating environmental pollution.

https://www.sciencedirect.com/science/article/abs/pii/S0013935122010684