Centre of Marine Sciences, CCMAR, Universidade Do Algarve, Campus de Gambelas, Edifício 7, 8005-139, Faro, Portugal.
Algarve Chemistry Research Centre, CIQA, Universidade Do Algarve, Campus de Gambelas, Edifício 2, 8005-139, Faro, Portugal.
Sci Rep. 2020 Oct 1;10(1):16343. doi: 10.1038/s41598-020-73338-z.
Stress triggers a battery of physiological responses in fish, including the activation of metabolic pathways involved in energy production, which helps the animal to cope with the adverse situation. Prolonged exposure to stressful farming conditions may induce adverse effects at the whole-animal level, impairing welfare. Fourier transform infrared (FTIR) spectroscopy is a rapid biochemical fingerprinting technique, that, combined with chemometrics, was applied to disclose the metabolic alterations in the fish liver as a result of exposure to standard stressful practices in aquaculture. Gilthead seabream (Sparus aurata) adults exposed to different stressors were used as model species. Spectra were preprocessed before multivariate statistical analysis. Principal components analysis (PCA) was used for pattern recognition and identification of the most discriminatory wavenumbers. Key spectral features were selected and used for classification using the k-nearest neighbour (KNN) algorithm to evaluate whether the spectral changes allowed for the reliable discrimination between experimental groups. PCA loadings suggested that major variations in the hepatic infrared spectra responsible for the discrimination between the experimental groups were due to differences in the intensity of absorption bands associated with proteins, lipids and carbohydrates. This broad-range technique can thus be useful in an exploratory approach before any targeted analysis.
应激会在鱼类中引发一系列生理反应，包括激活参与能量产生的代谢途径，这有助于动物应对不利情况。长时间暴露在应激性养殖环境中可能会在整体动物水平上产生不良影响，损害福利。傅里叶变换红外（FTIR）光谱是一种快速的生化指纹识别技术，与化学计量学结合使用，用于揭示鱼类肝脏由于暴露于水产养殖中的标准应激实践而导致的代谢变化。使用经过不同应激源处理的金头鲷（Sparus aurata）成鱼作为模型物种。在进行多元统计分析之前，对光谱进行了预处理。主成分分析（PCA）用于模式识别和识别最具区分性的波数。选择关键光谱特征，并使用 k-最近邻（KNN）算法进行分类，以评估光谱变化是否允许可靠地区分实验组。PCA 载荷表明，导致实验组之间区分的肝红外光谱的主要变化是由于与蛋白质、脂质和碳水化合物相关的吸收带强度的差异。因此，在进行任何靶向分析之前，这种广谱技术可以在探索性方法中发挥作用。
