Oxytetracycline fermentation residue (OFR) can be managed by bioprocesses to recycle organic substances. However, the organic materials present are resistant to biodegradation due to protection by the OFR matrix structure, and the high levels of residual oxytetracycline have unavoidably negative impacts on microorganisms in bioprocesses and result in the poor biodegradability of OFR. Hydrothermal treatment (HT) is promising for processing OFR to improve its biodegradability, but there is still insufficient practical experience with HT of OFR. To explore the applicability of employing HT as a pretreatment to improve the biodegradability of OFR, HT processes at temperatures varying from 90 °C to 180 °C were performed on OFR to disintegrate its matrix and inactivate the high levels of residual oxytetracycline. The results demonstrated that performing HT clearly enhanced the production of hydrophilic matter including soluble chemical oxygen demand (SCOD), soluble carbohydrates and soluble proteins. Nevertheless, the drawbacks of HT for degrading soluble organics and mineralizing total organics were clearly observed at 180 °C. Efficient destruction of the OFR matrix structure was speculated based on the release of carbohydrates and proteins and was visually confirmed by photomicrographs and scanning electron microscopy graphs. The disappearance of oxytetracycline fit a pseudo first-order kinetics model and the toxic intermediates of oxytetracycline, including 4-epi-oxytetracycline, α-apo-oxytetracycline and β-apo-oxytetracycline, could not be persistent during HT. Antibacterial activity linked to oxytetracycline greatly decreased after HT. The conditions of 150 °C and 180 min resulted in relatively good results in SCOD release and oxytetracycline inactivation. All these suggest that HT effectively improves the biodegradability of OFR.

土霉素发酵残留物（OFR）可以通过生物过程进行管理，以回收有机物质。但是，由于受到OFR基质结构的保护，存在的有机材料具有抗生物降解的能力，并且高残留量的土霉素会不可避免地对生物过程中的微生物产生负面影响，并导致OFR的生物降解性较差。水热处理（HT）有望用于加工OFR以提高其生物降解性，但是OFR HT的实践经验仍然不足。为了探索采用HT进行预处理以提高OFR的生物降解性的适用性，对OFR进行了从90°C到180°C的HT处理，以分解其基质并使高水平的土霉素残留失活。结果表明，进行HT明显增强了亲水物质的产生，包括可溶性化学需氧量（SCOD），可溶性碳水化合物和可溶性蛋白质。然而，在180°C时，HT明显具有降解可溶性有机物和使总有机物矿化的缺点。基于碳水化合物和蛋白质的释放推测OFR基质结构的有效破坏，并且通过显微照片和扫描电子显微镜图目测确认。土霉素的消失符合拟一级动力学模型，并且土霉素的有毒中间体包括4-表土霉素，HT在180°C时明显降解了可溶有机物和使总有机物矿化的缺点。基于碳水化合物和蛋白质的释放推测OFR基质结构的有效破坏，并且通过显微照片和扫描电子显微镜图目测确认。土霉素的消失符合拟一级动力学模型，并且土霉素的有毒中间体包括4-表-土霉素，HT在180°C时明显降解了可溶有机物和使总有机物矿化的缺点。基于碳水化合物和蛋白质的释放推测OFR基质结构的有效破坏，并且通过显微照片和扫描电子显微镜图目测确认。土霉素的消失符合拟一级动力学模型，并且土霉素的有毒中间体包括4-表-土霉素，HT期间，α-载脂蛋白四环素和β-载脂蛋白四环素不能持续存在。HT后，与土霉素有关的抗菌活性大大降低。在150°C和180分钟的条件下，SCOD释放和土霉素的失活效果相对较好。所有这些表明，HT有效地改善了OFR的生物降解性。