不同LETC离子束对粘红酵母菌的突变效应分析

Analysis of Mutagenic Effects Induced by Carbon Beams at Different LET in a Red Yeast Strain

以粘红酵母菌Rhodotorula glutinis AY 91015为材料,研究了不同传能线密度(LET)的C离子对粘红酵母菌的失活截面和突变截面,评估了不同LET的C离子对微生物的失活效应和突变效应。结果表明,C离子LET为120.0 keV/μm时,单个粒子对粘红酵母菌的失活截面最大,为4.37μm2,接近酵母菌细胞核的平均核截面;LET为96.0 keV/μm时,单个粒子对粘红酵母菌的突变截面最大。通过对C离子束致突变能力的分析发现,C离子在LET为58.2 keV/μm时突变能力最强,这一结果显示在经C离子辐照后存活下来的粘红酵母菌中,可以引起有效突变的最佳LET为58.2 keV/μm左右,此时所对应的碳离子能量约为35 MeV/u。这些结果表明,C离子对粘红酵母菌的最佳致死效应和最佳致突变效应存在于不同的能量区域。

To evaluate inactive and mutagenic effects of carbon beam at different LET,the inactivation cross section and mutation cross section induced by carbon beams of different LET values were investigated in a red yeast strain Rhodotorula glutinis AY 91015.It was found that the maximum inactivation cross section of 4.37μm^2,which was very close to the average nucleus cross section,was at LET of 120.0 keV/μm.The maximum mutation cross section was at LET of 96.0 keV/μm.Meanwhile,the highest mutagenicity of carbon ion was found around 58.2 keV/μm.It implied that the most efficient LET to induce mutation in survival yeasts was 58.2 keV/μm,which corresponded to energy of 35 MeV/u carbon beam.The most effective carbon beam to induce inactivation and mutation located at different energy region.