【摘要】 本文报道两种测定λ原噬菌体紫外诱导频率的新方法—菌落计数法和平板诱导法。将溶源菌液经紫外诱导暗培养稀释后直接涂布在平板上培养 ,根据平板上菌落形成单位数计算λ噬菌体紫外诱导频率。另一种是将溶源菌与指示菌混合制备的平板用紫外线诱导 ,根据平板上噬菌体形成单位确定λ噬菌体紫外诱导频率。这两种方法不仅能准确测定噬菌体紫外诱导频率 ,而且操作简便 ,节省时间和用具 ,重复性好。本研究还将冬虫夏草浸出汁与溶源菌混合后进行紫外辐射 ,通过几种方法进行比较 ,结果证明建立的新方法确实可行 ,易操作 ;同时也表明冬虫夏草具有较强的抗紫外辐射作用更多还原

【Abstract】 Two new methods, colony counting method and plate inducing method, were established for determining ultraviolet induction rate of λ prophage in the present study. Culture of lysogenic bacteria(λ ) which was induced by ultraviolet irradiation and cultivated in dark was directly spread on the plate, and induction rate of λ prophage was calculated based on the CFUs (colony forming units). The plate with mixture of lysogenic bacteria and indicator strain was induced by ultraviolet irradiation. The induction rate of λ prophage was calculated based on the PFUs (plaque forming units). These two methods not only can determine precisely induction frequency of λ prophage, but also are easy to manipulate ,and they can save efforts and apparatus, they are also easy to repeat. Furthermore, the mixture of \%Cordyceps sinensis\% extract and lysogenic bacteria was irradiated with UV. The results demonstrate that the new methods are practical and easy to conduct, and that \%Cordyceps sinensis\% has a strong protection effect against UV irradiation.更多还原