1疑问《高中生物·选修1·生物技术实践》P.23:“在做本课题实验时A同学从对应的10~6倍稀释的培养基中只筛选出大约150个菌落。但是其他同学在同样稀释度下只选择出50个菌落。其他同学认为A的结果有问题。他们分析可能是A同学的培养基被杂菌污染了,或者培养基中混入了其他含氮物质,因而导致不能分解尿素的细菌也能在该培养基上生长。”廖乐祥[安徽省望江中学(246200)]“培养基 1 Question ”High School Biology · Elective 1 · Biotechnology Practice“ P.23: ”In the current study, students A only screened about 150 colonies from the corresponding 10 to 6-fold dilution medium, but other students Only 50 colonies were selected at the same dilution.Other students think that the results of A. There was a problem that their analysis might be that A’s medium was contaminated by miscellaneous bacteria or that other nitrogenous substances were mixed in the medium, Bacteria that decompose urea can also grow on this medium. “” Liao Le-xiang [Wangjiang Middle School, Anhui Province (246200)] "