The residual erythromycin in fermentation waste can pollute the environment and threaten human health. However, there are no effective approaches to remedy this issue. In this study, an erythromycin‐degrading bacterium named RJJ‐61 was isolated and identified as a strain of Delftia lacustris based on morphological and phylogenetic analyses. The degradation ability of this strain was also evaluated; it could degrade 45.18% of erythromycin at 35°C in 120 h. Furthermore, the key degradation gene ereA was cloned from strain RJJ‐61 and expressed in Escherichia coli BL21; the molecular weight of the expressed protein was ~45 kDa. The enzyme activity of EreA was 108.0 mU ml−1 at 35°C and pH 7.0. Finally, the EreA protein was used to degrade erythromycin from mycelial dregs and 50% diluted solution, and the removal rates in them were 41.42% and 69.78%, respectively. In summary, D. lacustris RJJ‐61 is a novel erythromycin‐degrading strain that has great potential to remove erythromycin pollutants from the environment.

中文翻译：

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Delftia lacustris RJJ-61对红霉素的生物降解及其红霉素酯酶的表征

发酵废料中残留的红霉素会污染环境，威胁人类健康。然而，没有有效的方法来解决这个问题。在这项研究中，基于形态学和系统发育分析，分离出一种名为 RJJ-61 的红霉素降解细菌并鉴定为 Delftia lacustris 菌株。还评估了该菌株的降解能力；35℃下120h可降解45.18%的红霉素。此外，从菌株RJJ-61中克隆出关键降解基因ereA并在大肠杆菌BL21中表达；表达蛋白的分子量为~45 kDa。EreA 的酶活性在 35°C 和 pH 7.0 时为 108.0 mU ml-1。最后用EreA蛋白从菌丝渣和50%稀释液中降解红霉素，去除率分别为41.42%和69.78%，分别。总之，D. lacustris RJJ-61 是一种新型的红霉素降解菌株，具有从环境中去除红霉素污染物的巨大潜力。