低剂量γ辐射对青海弧菌Q67的毒性研究

Study on toxicity of low dose γ radiation to Qinghai Vibrio Q67

分别采用生物辐照仪和模拟铀矿室作为γ辐照源,研究了低剂量和超低剂量γ照射对青海弧菌Q67发光强度和光密度(OD_(600))的影响。实验结果表明,青海弧菌Q67在5.5 c Gy/min照射剂量率、不同累积照射剂量γ射线照射下,在一定累积照射剂量范围内,发光强度的抑制率无显著差异,当累积照射剂量超过该范围的累积照射剂量的阈值后,发光强度抑制率与累积照射剂量呈正相关。青海弧菌Q67在320 m Gy累积照射剂量,5.5、14和51 c Gy/min 3个不同照射剂量率γ射线照射下,发光强度在低照射剂量率、长时间的γ射线照射条件下抑制率更大。青海弧菌Q67在长时间超低γ射线照射剂量率的条件下,菌液的OD_(600)值的抑制率在24 h达到最大值,此后逐渐降低,其中30和120μGy/h两组剂量率照射下,青海弧菌Q67菌体数呈现低剂量兴奋效应。通过测定低剂量和超低剂量γ射线照射对青海弧菌Q67的发光强度和菌液OD_(600)值的抑制率,可反映一定剂量范围内的γ射线照射对青海孤菌Q67的综合毒性作用。青海孤菌Q67对γ射线具有较好的敏感性,可用作低剂量γ射线毒性评价的生物材料。

The effects of low dose and ultra-low dose γ radiation on luminous intensity and optical density（OD600） of Qinghai Vibrio Q67 were studied using biological irradiator and simulated uranium irradiation chamber as γ radiation source. The results showed that the luminous intensity inhibition rates of Qinghai Vibrio Q67 were no significant difference when the cumulative radiation dose varied within a certain range at a dose rate of 5. 5 cGy/min. Once over the dose threshold value in this range,there was a positive correlation between the luminous intensity inhibition rate and the cumulative radiation dose. Moreover, Qinhai Vibrio Q67 irradiating with 320 mGy cumulative radiation dose at three different irradiated dose of 5. 5,14 and 51 cGy/min,it was found that its luminous intensity inhibition rate increased on the condition of low dose rate and long time γ ray radiation. Qinhai Vibrio Q67 irradiated with γ rays at ultra low dose rate for long time the inhibition rate of the OD600 value reached the maximum at 24 h,and then reduced gradually. The hormesis of Qinghai Vibrio Q67 occurred with γ dose rates both at 30 and at 120 μGy/h. It was feasible to establish biological early warning method by calculating the inhibition rate of luminous intensity and OD600 values of Qinghai Vibrio Q67 in low dose and ultra-low dose γ irradiation.