Microbial degradation is an important option for combating antibiotic pollution. Arthrobacter nicotianae OTC-16 was isolated as a novel tetracycline-degrading bacterium, which could degrade oxytetracycline/tetracycline (OTC/TET). Toxicity assessment indicated that this bacterium effectively converted OTC into byproducts with less toxicity to bacterial and algal indicators. Six degradation products of OTC were tentatively identified, and a potential biotransformation pathway was proposed that includes decarbonylation, reduction, and dehydration. Bioaugmentation of TC removal with this bacterium was further studied in various matrices. In aqueous media, strain OTC-16 accelerated OTC removal over a temperature range of 20–35 ℃, pH range of 6.0–9.0, and OTC concentration range of 25–150 mg L⁻¹. The strain also facilitated the decrease of OTC and TET concentrations in both swine and chicken manures, with a maximum decrease of 91.54%, and increased the degradation of OTC in soils by 8.22–45.45%. A unique advantage of this bacterium in promoting OTC degradation in alkaline environments was demonstrated, where it successfully competed with the indigenous microbiota and largely decreased the relative abundances of the studied tetracycline resistance genes (tetB and tetW) in soil. This work offers a better understanding of the antibiotic bioaugmentation and new microbial sources.

微生物降解是对抗抗生素污染的重要选择。分离到烟草节杆菌OTC-16，它是一种新型的降解四环素的细菌，可降解土霉素/四环素（OTC / TET）。毒性评估表明，该细菌有效地将OTC转化为对细菌和藻类指示剂毒性较小的副产物。初步确定了OTC的六种降解产物，并提出了潜在的生物转化途径，包括脱羰，还原和脱水。在各种基质中进一步研究了这种细菌对TC的生物强化作用。在水性介质中，OTC-16菌株在20–35℃的温度范围，6.0–9.0的pH范围和25–150 mg L ^-1的OTC浓度范围内加速了OTC的去除。。该菌株还促进了猪粪和鸡粪中OTC和TET浓度的降低，最大降低幅度为91.54％，并使土壤中OTC的降解增加了8.22-45.45％。证明了该细菌在碱性环境中促进OTC降解的独特优势，它可以与本地微生物群成功竞争，并大大降低了土壤中研究的四环素抗性基因（tet B和tet W）的相对丰度。这项工作可以更好地了解抗生素的生物强化作用和新的微生物来源。