Raman Spectra Analysis for Single Mitochondrias after Apoptosis Process of Yeast Cells Stressed by Acetic Acid

Laser tweezers Raman spectroscopy (LTRS) as a non-invasive tool for mitochondria analysis, combined with oxygen electrode and ultraviolet spectrophotometric method, was used to investigate the Raman spectra of mitochondria of yeast cells in vitro and in vivo after induced with acetic acid. The results showed that when the mitochondria of yeast cells in vivo was induced by acetic acid, the spectral peaks of the nucleic acid (1081 and 1301 cm−1), proteins (872, 1604, 1445 and 1657 cm−1), lipids (1125, 1301, 1445 and 1657 cm−1), cytochrome c (750 and 1125 cm−1) and mitochondria respiration (1604 cm−1) were significantly decreased as a function of the duration of the acetic acid stress, and the obtained physiological and biochemical indexes of respiration rate, phosphorous/oxygen (P/O) ration and cytochrome c content were similar to those by conventional method. Furthermore, when the mitochondria of yeast cells in vitro was induced by acetic acid, the spectral peaks of the nucleic acid (1081 and 1301 cm−1), proteins (872, 1604, 1445 and 1657 cm−1), lipids (1125, 1301, 1445 and 1657 cm−1), cytochrome c (750 and 1125 cm−1) and mitochondria respiration (1604 cm−1) were significantly decreased as the function of the duration of the acetic acid stress, and the obtained physiological and biochemical indexes of respiration rate, P/O ration and cytochrome c content were similar to those by conventional method. The results indicated that acetic acid could penetrate into the cell interior and directly impacted the mitochondria possibly, resulting in the release of inclusions from the mitochondria, subsequently, causing the apoptosis of yeast cells via mitochondrial pathway-induced apoptosis.

The Raman spectra of a single yeast mitochondrion (a) and pure Cyt c (b) show that Cyt c has the characteristic peaks at 750, 1125, 1314 and 1580 cm−1 and yeast mitochondrion has the characteristic peaks at 750 and 1125 cm−1. The illustration in the top left corner of figure is the mitochondria image (× 100), and the scale bar is 1 μm.Figure optionsDownload as PowerPoint slide