土壤放线菌分离杂菌抑制方法研究

Study on Inhabition Methods to Miscellaneous Microorganism for Soil Actinomycetes Isolation

采用平板涂布法研究了土样不同预处理方法、杂菌抑制剂种类对土壤放线菌分离效果的影响。结果表明：风干处理（7～10d）土样,放线菌的分离效果优于热处理（120℃×1h）,所分离到的放线菌数量和种类较多,且易于纯化,杂菌（细菌、真菌）明显减少,而供试土样经120℃热处理1h几乎未分离出放线菌,细菌数量仍较多,真菌全部被杀死;通过对4种杂菌抑制剂及其组合反复试验,选择出了土壤放线菌分离与纯化适宜的杂菌抑制剂种类（S＋Q）和最佳用量,山梨酸钾（S）、氨苄西林钠（Q）在GA中的最佳使用剂量分别为30、3mg/L,而重铬酸钾（Z）及其组合Z＋Q对土壤细菌、真菌也有一定的抑制作用,但抑菌效果比S＋Q差,且放线菌的分离数量也较低。因此,进行风干处理土样和向放线菌分离培养基（GA）中加入杂菌抑制剂S＋Q双重处理,可得到土壤放线菌分离与纯化较佳的效果。

The influence of different pretreatment ways of the soil samples and miscellaneous microorganism inhibitors to the isolation effect of soil actinomycetes was studied by plate paint isolation method.The results showed that actinomycetes isolation effect of air drying（7-10days）soil samples was better than that of heat treatment（120℃×1hour）.The number of actinomycetes isolated and kinds were more,and easily purified,and miscellaneous microorganism（bacteria,fungi）also decreased significantly.However,actinomycetes were hardly isolated in the soil samples that were treated with 120℃×1hour,bacteria number was still more,fungi were all killed;by testing repeatedly four kinds of miscellaneous microorganism inhibitors and their combinations,suitable inhibitor（S＋Q）and its optimal dosage of soil actinomycetes isolation and purification were selected out.The optimum dosages of potassium sorbate（S）and ampicillin sodium（Q）were 30mg/L and 3mg/L,respectively.Potassium dichromate（Z）and its combinations（Z＋Q）also had certain inhibitory effect on soil bacteria and fungi,but their inhibitory effect were not as well as those of S＋Q,and isolation number of actinomycetes also were lower.Therefore,through double dealing with air drying soil samples and adding S＋Q in actinomycetes isolation medium（GA）,better effect of soil actinomycetes isolation and purification were available.