Godoy F A, Bunster M, Matus V, Aranda C, González B, Martínez M A
Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla, Concepción, Chile.
Lett Appl Microbiol. 2003;36(5):315-20. doi: 10.1046/j.1472-765x.2003.01315.x.
To analyse the possible effect of poly-beta-hydroxyalkanoate (PHA) consumption on 2,4,6-trichlorophenol (2,4,6-TCP) degradation during starvation by Sphingopyxis chilensis S37 strain, which stores PHAs and degrades 2,4,6-TCP.
The strain was inoculated in saline solution supplemented with 2,4,6-TCP (25-400 microm). Chlorophenol degradation was followed both spectrophotometrically and by chlorine released; viable bacterial counts were also determined. Cells starved for 24, 48 or 72 h were incubated with 25 microm of 2,4,6-TCP and PHA in cells investigated by spectrofluorimetric and flow cytometry. Results demonstrated that starvation decreased the ability to degrade 2,4,6-TCP. After 72 h of starvation, degradation of 2,4,6-TCP decreased to less than 10% and the relative PHA content diminished to ca 50% during the first 24 h.
Utilization of PHA may be an important factor for the degradation of toxic compounds, such as 2,4,6-TCP, in bacterial strains unable to use this toxic compound as carbon and energy source.
This is the first study describing a relationship between intracellular PHA consumption and 2,4,6-TCP degradation. Therefore, PHAs provides an endogenous carbon and energy source under starvation and can play a significant role in the degradation of toxic compounds.
分析嗜智利鞘氨醇菌S37菌株（该菌株储存聚羟基脂肪酸酯并降解2,4,6-三氯苯酚）在饥饿期间消耗聚-β-羟基链烷酸酯（PHA）对2,4,6-三氯苯酚（2,4,6-TCP）降解的可能影响。
将该菌株接种于补充有2,4,6-TCP（25 - 400微摩尔）的盐溶液中。通过分光光度法和释放的氯来跟踪氯酚的降解；还测定了活菌数。对饥饿24、48或72小时的细胞，用25微摩尔的2,4,6-TCP和PHA进行孵育，并通过荧光分光光度法和流式细胞术研究细胞中的情况。结果表明，饥饿降低了降解2,4,6-TCP的能力。饥饿72小时后，2,4,6-TCP的降解率降至10%以下，相对PHA含量在前24小时内降至约50%。
对于无法将这种有毒化合物用作碳源和能源的细菌菌株，PHA的利用可能是降解有毒化合物（如2,4,6-TCP）的一个重要因素。
这是第一项描述细胞内PHA消耗与2,4,6-TCP降解之间关系的研究。因此，PHA在饥饿状态下提供内源性碳源和能源，并在有毒化合物的降解中发挥重要作用。
