Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160-C, Concepcion, Chile.
Curr Microbiol. 2009 Dec;59(6):636-40. doi: 10.1007/s00284-009-9485-9. Epub 2009 Aug 29.
Several bacterial species have developed physiological response to avoid the cellular damage when are exposed to carbon starvation or frozen stress. For example survival to inanition has been related to endogenous substrates consumptions. The aim of this study was to evaluate if poly-beta-hydroxylkanoates (PHA) consumption enable Sphingopyxis chilensis S37 to survive under carbon starvation or frozen condition. Bacterial cells were grown in R(2)A broth for 48 h, and suspended in mineral saline solutions, without carbon source. The cellular suspension was incubated for 48 or 120 h at 30 degrees C, followed by a frozen period of 48 h at -20 degrees C, and viable bacterial cells were evaluated by the microdrop method. The proportions of cells with PHA were also determined by flow cytometry using Nile Red dye. The results indicate that S. chilensis were able to survive under carbon starvation and frozen conditions. Simultaneously, a decrease in the number of cells containing PHA, and a decrease in the biovolume of the cells (c.a 2.5 times) were also observed under these conditions. The results suggest that consumptions of PHA contributed to the surviving of S. chilensis under frozen stress.
一些细菌物种已经发展出生理反应，以避免在暴露于碳饥饿或冷冻应激时发生细胞损伤。例如，对饥饿的生存能力与内源性底物的消耗有关。本研究旨在评估聚-β-羟基烷酸（PHA）的消耗是否使地嗜皮菌 S37 能够在碳饥饿或冷冻条件下存活。将细菌细胞在 R(2)A 肉汤中培养 48 小时，然后悬浮在无碳源的生理盐水溶液中。细胞悬浮液在 30°C 下孵育 48 或 120 小时，然后在-20°C 下冷冻 48 小时，通过微滴法评估活菌细胞。还通过使用尼罗红染料的流式细胞术来确定含有 PHA 的细胞的比例。结果表明，S. chilensis 能够在碳饥饿和冷冻条件下存活。同时，在这些条件下，还观察到含有 PHA 的细胞数量减少，以及细胞生物量减少（约 2.5 倍）。结果表明，PHA 的消耗有助于 S. chilensis 在冷冻应激下存活。
