选择性分离放线菌

Selective Isolation of Actinomycetes

进行了土样的预处理试验，探讨了平板培养基中抑制剂重酪酸钾的最适浓度．结果表明，选择性分离放线菌的比较适宜的方法为：采集的土样在２８℃或室温条件下风干１０～２０ｄ后，将土壤悬浮液（１０－１）于４０℃和ｐＨ７的条件下，加６％酵母膏和０．０５％ＳＤＳ（５ｍｍｏｌ／Ｌ磷酸缓冲液），震荡２０ｍｉｎ，水稀释至１０－２；或土壤悬浮液（１０－１）于５０℃和ｐＨ７的条件下，加６％胨和０．０５％ＳＤＳ（５ｍｍｏｌ／Ｌ磷酸缓冲液），震荡１０ｍｉｎ，水稀释至１０－２．然后用平板稀释法接菌在高氏合成１号琼脂＋重酪酸钾（质量浓度为２５０ｍｇ／Ｌ）的平板培养基上。

The studies on pretreatment of soil samples were conducted.The optimum concentration of the inhibitor K2Cr2O7 in the plate medium was studied.Results show that the suitable method of the selective isolation of actinomycetes is that,after the collected soil samples are dried at 28 or at indoor temperature for 10 to 20 days, the soil suspension(101)added with 6% yeast extract and 0.05% SDS (5 mmol/L phosphate buffer) is stirred at 40, pH7 for 20 minutes,or the soil suspension(101) added with 6% peptone and 0.05% SDS (5mmol/L phosphate buffer) is stirred at 50, pH7 for 10 minutes,then the colonies of actinomycetes is picked out from the agar medium after the soil suspension diluted with water to 102 is inoculated with the method of plate dilution on the Gause's starch agar added with 250 mg K2Cr2O7/L medium for 7 days.