饲料总菌数的测定.doc

饲料总菌数的测定.doc饲料中细菌总数的测定方法标准类别:农业饲料标准实施日期:点击:236         本标准参照采用国际标准  ISO4833—1978《食品和动物饲料中微生物学检验方法》。        1        主题内容与适用范围        本标准规定了饲料中细菌总数的测定方法。        本标准适用于饲料中细菌总数的测定。        2  原理        将试样稀释至适当浓度,用特定的培养基,在30±1℃下培养72±3h,计数平板中长出的菌落数,计算每克试样中的细菌数量。        3        仪器、设备            天平:。            振荡器:往复式。            干热灭菌箱:50-200±1℃。            高压灭菌锅。            冰箱:普通冰箱。            恒温箱30±51℃  。            电炉:可调式。            平皿:直径为9cm。            吸管:容量为1、10mL。          三角烧瓶:容量为  250、500mL。          玻璃珠。          试管:18×180mm。          水浴锅46±1℃。          酒精灯。          试管架。          橡皮乳头。        4        检验程序        细菌总数的检验程序如下:                                                                                  检样                                                                          ↓                                                    做成几个适当倍数的稀释液                                                                          ↓                                选择2-3个适宜稀释度,各以1ml量加入灭菌皿内                                                                                      ↓                                                        每平皿内加入适量琼脂                                                          30±1℃  ↓  72±3h                                                                    菌落计数