School of Environmental Science and Engineering, Shandong Key Laboratory of Environmental Processes and Health, China-America CRC for Environment & Health of Shandong Province, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, PR China.
School of Environmental Science and Engineering, Shandong Key Laboratory of Environmental Processes and Health, China-America CRC for Environment & Health of Shandong Province, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, PR China; Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangdong Province, PR China.
Environ Res. 2022 Nov;214(Pt 3):114111. doi: 10.1016/j.envres.2022.114111. Epub 2022 Aug 17.
Many Gram-negative pathogens enter the viable but nonculturable (VBNC) state to resist external environmental stress (such as disinfection). However, little is known about the metabolic properties, especially for the metabolic markers, of VBNC bacteria, which impedes the development of efficient disinfection technologies and causes more potential health risks. In this study, we analyzed the metabolic characteristics of chlorine stress-induced VBNC Pseudomonas aeruginosa at the population and single-cell levels. The overall metabolic activity of VBNC bacteria showed a downward trend, but the glyoxylate cycle, fatty acid and glycerophospholipid metabolism pathways were up-regulated. Based on the metabolic profiles of VBNC bacteria, nine metabolic markers (pyruvate, glyoxylate, guanine, glutamate, sn glycero-3-phos-phocholine, fatty acid, D-alanine, glutathione, N-Butanoyl-D-homoserine lactone) were determined. The results of single-cell Raman spectroscopy showed that the metabolic activity of VBNC bacteria was significantly reduced, but showed more significant metabolic heterogeneity. The redshift of the Raman peaks of N and C labeled VBNC bacteria was significantly weaker than that of the culturable bacteria, suggesting that the VBNC bacteria have a reduced ability to synthesize proteins, nucleotides, phospholipids, and carbohydrates. The result of this study can help to better understand the metabolic mechanisms and energy management strategy of VBNC bacteria, to achieve precise identification and effective control of VBNC bacteria.
许多革兰氏阴性病原体进入活的但非可培养状态（VBNC）以抵抗外部环境压力（如消毒）。然而，对于 VBNC 细菌的代谢特性，特别是代谢标志物，知之甚少，这阻碍了高效消毒技术的发展，并带来了更多潜在的健康风险。在这项研究中，我们在群体和单细胞水平上分析了氯应激诱导的 VBNC 铜绿假单胞菌的代谢特性。VBNC 细菌的整体代谢活性呈下降趋势，但乙醛酸循环、脂肪酸和甘油磷脂代谢途径被上调。基于 VBNC 细菌的代谢谱，确定了九个代谢标志物（丙酮酸、乙醛酸、鸟嘌呤、谷氨酸、sn 甘油-3-磷酸胆碱、脂肪酸、D-丙氨酸、谷胱甘肽、N-丁酰-D-高丝氨酸内酯）。单细胞拉曼光谱的结果表明，VBNC 细菌的代谢活性显著降低，但表现出更显著的代谢异质性。标记 N 和 C 的 VBNC 细菌的拉曼峰红移明显弱于可培养细菌，这表明 VBNC 细菌合成蛋白质、核苷酸、磷脂和碳水化合物的能力降低。本研究的结果有助于更好地理解 VBNC 细菌的代谢机制和能量管理策略，实现对 VBNC 细菌的精确识别和有效控制。
