Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049 Saratov, Russia.
Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049 Saratov, Russia.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 May 5;252:119458. doi: 10.1016/j.saa.2021.119458. Epub 2021 Jan 9.
Monitoring of poly-3-hydroxybutyrate accumulation and changes in its relative contents in biomass of the plant-growth-promoting bacteria Azospirillum brasilense (strains Sp7, Cd and Sp245) was performed during aerobic cultivation for 1 to 8 days at various initial concentrations of bound nitrogen (0.1 to 0.5 g∙L NHCl) in the culture medium using in-situ transmission FTIR spectroscopy. A methodology has been proposed based on calculating band areas in FTIR spectra (instead of band intensities commonly used earlier) for determining relative contents of PHB in dry bacterial biomass, using the ester ν(C=O) band as a PHB marker (in the region 1750-1720 cm) and amide II band of cellular proteins (at ca. 1540 cm). Differences in PHB accumulation levels and their changes in the course of cultivation under various trophic stress for the three strains are discussed in relation to their different ecological niches which they occupy in the rhizosphere.
采用原位传输傅里叶变换红外光谱法，在有氧培养条件下，监测植物促生细菌 Azospirillum brasilense（Sp7、Cd 和 Sp245 菌株）在不同初始结合态氮浓度（0.1 至 0.5 g·L NHCl）下的聚 3-羟基丁酸（PHB）积累及其在生物量中相对含量的变化，培养时间为 1 至 8 天。本研究提出了一种基于计算傅里叶变换红外光谱（FTIR）谱带面积（而不是常用的强度）的方法，用于确定干燥细菌生物质中 PHB 的相对含量，使用酯 ν（C=O）带作为 PHB 标记（在 1750-1720 cm 区域）和细胞蛋白质的酰胺 II 带（约 1540 cm）。讨论了在三种菌株不同的营养胁迫下培养过程中 PHB 积累水平及其变化的差异，以及它们在根际中所占据的不同生态位。
