Xu Yongdong, Lu Jianwen, Wang Yueyao, Yuan Changbin, Liu Zhidan
Laboratory of Environment-Enhancing Energy (E2E), College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China.
Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China.
J Hazard Mater. 2022 Feb 5;423(Pt B):127162. doi: 10.1016/j.jhazmat.2021.127162. Epub 2021 Sep 11.
Hydrothermal liquefaction aqueous phase (HTL-AP) is complex and toxic, which severely hinders the scale-up of HTL technology. Distinguished from degrading organics and extracting chemical energy or nutrients from HTL-AP via biological fermentation or algae cultivation, here, we propose an innovative strategy to valorize the HTL-AP as a powerful anti-bacterial pool. Six model ingredients, i.e. lipids, cellulose, xylan, lignin, protein and the mixture were employed, to obtain a thirty-HTL-AP pool for characteristics database construction. We found that the xylan group at 230 °C on Escherichia coli (E. coli) and at 200 °C on Staphylococcus aureus (S. aureus) exhibited the highest anti-bacterial activities via plate experiments, nearly equal to 100 μg/ml streptomycin which far exceeded the working concentration of streptomycin (10-50 μg/ml). The liquid cultivation studies further revealed HTL-APs from the mixture feedstock, protein, real biomass microalgae and cornstalk had more stable anti-bacterial activities as chemically stable substances. Interestingly, the Gram-positive strain S. aureus was more susceptible than the Gram-negative E. coli on the HTL-APs, probably owing to the outer selectively permeable membrane difference and the strong reducibility and acidity of HTL-APs. This study provides a new vision to seek the anti-bacterial potential of HTL aqueous, supporting further investigations on its molecular mechanism and new bactericide development.
水热液化水相（HTL-AP）复杂且有毒，这严重阻碍了HTL技术的规模化应用。与通过生物发酵或藻类培养降解有机物以及从HTL-AP中提取化学能量或营养物质不同，在此，我们提出了一种创新策略，将HTL-AP作为一种强大的抗菌库加以利用。使用了六种模型成分，即脂质、纤维素、木聚糖、木质素、蛋白质及其混合物，以获得一个包含30种HTL-AP的库用于构建特征数据库。通过平板实验，我们发现230℃下的木聚糖组对大肠杆菌（E. coli）以及200℃下的木聚糖组对金黄色葡萄球菌（S. aureus）表现出最高的抗菌活性，几乎等同于100μg/ml的链霉素，这远远超过了链霉素的工作浓度（10 - 50μg/ml）。液体培养研究进一步表明，来自混合原料、蛋白质、实际生物质微藻和玉米秸秆的HTL-AP作为化学稳定物质具有更稳定的抗菌活性。有趣的是，革兰氏阳性菌金黄色葡萄球菌对HTL-APs比革兰氏阴性菌大肠杆菌更敏感，这可能归因于外部选择性渗透膜的差异以及HTL-APs的强还原性和酸性。本研究为探索HTL水相的抗菌潜力提供了新视角，支持对其分子机制和新型杀菌剂开发的进一步研究。
