尽管热声处理(TS)处理已广泛用于食品灭菌,TS治疗的细菌的存活但不可培养(VBNC)仍然关注潜在的食品安全和公共卫生。用TS处理的细菌的VBNC状态的分子机制尚不清楚。因此,在这项研究中,我们用了希瓦氏菌,这是水产品中常见的腐败细菌,研究TS处理细菌的VBNC状态。首先,我们的结果表明,在TS处理后,腐殖质仍然可以进入VBNC状态:50kHz,300W,30分钟超声处理和70°C加热;随后,我们发现腐乳链球菌的VBNC状态可以抵抗TS治疗的损害,如细胞壁破裂,DNA降解,等等;最后,基于四维数据独立采集的蛋白质组学研究表明,在VBNC状态下,S.putrefaciens上调功能蛋白以抵抗TS治疗,如:核糖体蛋白加速应激蛋白的合成,以抵消TS治疗,鸟氨酸脱羧酶SpeF和MraY修复TS治疗引起的损伤,等。同时,S.putrefaciens下调代谢和转运功能蛋白如脱氢酶以减少代谢。重要的是,在这些蛋白质中,核糖体转录调节蛋白家族,例如rpsB,etc,可能是腐败链球菌进入VBNC状态的关键蛋白。这一发现可以为预防TS治疗细菌的VBNC状态提供一些新策略。例如:抑制关键蛋白质,等。
Although thermosonication (TS) treatment has been widely used in food sterilization, the viable but non-culturable (VBNC) of bacteria with TS treatment has still concerned potential food safety and public health. The molecular mechanism of VBNC status of bacteria with TS treatment is not clearly known. Therefore, in this study, we used Shewanella putrefaciens, which was a common putrefactive bacteria in aquatic products, to study the VBNC state of bacteria with TS treatment. Firstly, our results revealed that S. putrefaciens still could enter the VBNC state after TS treatments: 50 kHz, 300 W, 30 min ultrasonic treatment and 70 °C heating; Subsequently, we found the VBNC state of S. putrefaciens can resist the damage of TS treatment, such as cell wall break, DNA degradation, etc; Finally, four-dimensional data-independent acquisition-based proteomics showed that under VBNC state, S. putrefaciens upregulated functional proteins to resist TS treatment, such as: ribosomal proteins to accelerate the synthesis of stress proteins to counteract TS treatments, ornithine decarboxylase SpeF and MraY to repair TS treatment-induced damage, etc. Meanwhile, S. putrefaciens downregulates metabolic and transport functional proteins such as dehydrogenase to reduce the metabolism. Importantly, among those proteins, the ribosomal transcriptional regulatory protein family, such as rpsB, etc, may be the key proteins for S. putrefaciens entering VBNC state. This finding can provide some new strategies for preventing VBNC status of bacteria with TS treatment, such as: inhibition of key proteins, etc.