红球菌R04细胞的不对称分裂及其在联苯胁迫下的分裂抑制

Asymmetric cell division of Rhodococcus sp. R04 and its division inhibition under biphenyl stress

【目的】研究红球菌R04细胞的分裂方式及联苯对其形态和细胞分裂的影响。【方法】以一株多氯联苯降解菌株(Rhodococcus sp.R04)为研究对象,利用荧光显微镜、扫描电子显微镜及透射电子显微镜分析红球菌R04在不同培养条件下的细胞分裂。【结果】红球菌R04细胞表现出对称分裂(约占30%)和不对称分裂(约占70%)两种分裂方式,且培养条件不影响不对称分裂细胞所占的比例。细胞分裂过程中,隔膜主要分布于细胞长度的30%–50%。在联苯的分解代谢过程中,红球菌R04细胞的生长分裂会受到联苯的抑制,但不影响红球菌R04细胞的分裂方式,在联苯胁迫下,细胞形成丝状化,表现出异常分裂,随着培养时间的延长,在细胞生长指数后期至转换期,细胞能够进行正常分裂。【结论】环境异生型化合物联苯/多氯联苯对其降解菌株——红球菌R04细胞的生长和分裂有较强影响,但是并不影响其分裂方式。

[Objective] To study the division of Rhodococcus sp. R04 cells and the effect of biphenyl on cellular morphology and cell division. [Methods] Using fluorescence microscopy, scanning electron microscopy and transmission electron microscopy, we analyzed the division of R. R04 cells cultured under different conditions. [Results] Rhodococcus sp. R04 exhibited asymmetric and symmetric division, and the proportion of the two types of division was about 7：3. The culture conditions did not affect the proportion of asymmetric division cells. The septum was located on the center to the poles, with some clustering at 30% and 50% of the cell length.Rhodococcus sp. R04 degraded biphenyl, but its division would be inhibited by biphenyl. Microscopic observation showed that Rhodococcus sp. R04 cells formed filaments and exhibited abnormal division in early exponential phase under biphenyl culture conditions. As the culture time was prolonged, the cells finally restored normal division. [Conclusion] Biphenyl/polychlorinated biphenyl has a strong effect on the reproduction and growth of Rhodococcus sp. R04 cell, but it does not affect the mode of cell division.