Hawai'i Natural Energy Institute, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
J Microbiol Methods. 2011 Oct;87(1):49-55. doi: 10.1016/j.mimet.2011.07.009. Epub 2011 Jul 23.
Poly(3-hydroxybutyrate) (PHB), a representative polyhydroxyalkanoate (PHA), is a naturally occurring biopolyester stored as tiny, intracellular granules in microbial cells. In vivo, native PHB granules are amorphous, stabilized by a monolayer membrane and intra-granule water. When subjected to varying environmental conditions, the native granules may become partially crystalline. The in situ crystallinity of native PHB granules in Ralstonia eutropha cells suspended in aqueous solution was monitored with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). No sample preparation was required for measurement. A major measurement error could be caused by the evaporation of water. Therefore, the infrared absorption spectra should be taken after the initial settlement of cells, but before excessive dehydration. Background interference caused by water and non-PHB biomass was constant throughout the time course of measurement, regardless of granule crystallinity. The wavenumber 1184 cm(-1) was found to be most sensitive to the in situ crystallinity of native PHB granules.
聚（3-羟基丁酸酯）（PHB）是一种代表性的聚羟基烷酸酯（PHA），是一种天然存在的生物聚酯，以微小的、细胞内的颗粒形式储存在微生物细胞中。在体内，天然 PHB 颗粒是无定形的，由单层膜和颗粒内的水分稳定。当受到不同的环境条件影响时，天然颗粒可能会部分结晶。用衰减全反射傅里叶变换红外光谱（ATR-FTIR）原位监测悬浮在水溶液中的 Ralstonia eutropha 细胞中天然 PHB 颗粒的原位结晶度。测量不需要进行样品制备。由于水分蒸发，可能会导致主要的测量误差。因此，红外吸收光谱应在细胞初始沉降后但在过度脱水之前进行测量。无论颗粒结晶度如何，水和非 PHB 生物质引起的背景干扰在整个测量过程中都是恒定的。发现波数 1184 cm(-1) 对天然 PHB 颗粒的原位结晶度最敏感。
