问题 问答题 简答题

简述实罐灭菌的优缺点

答案

参考答案:

优点:

1设备投资少(利用发酵罐将罐和培养基一同进行加热灭菌,无需另备灭菌设备);

2灭菌后再次染菌的危险性较小;

3适宜易发泡、黏度大和含固形物较多的培养基。

缺点:

1间歇操作,加热和冷却时间长,发酵周期长,发酵

2罐的周转率低,不能适应大规模连续生产的要求;

3无法采用高温短时间灭菌,培养基营养成分被破坏。

选择题

指出下列句子中,哪一个划线单词的重音位置与其他划线单词不同,将序号填在括号内。

( ) 1. Remember to meet me at the library in the Republic Square the day after tomorrow.

                   A                                    B                  C                                          D

( ) 2. —Ask them to write a report  about the programme.

                                                A        B                C 

            —OK. That's a good idea.

                                            D

( ) 3. A person with good manners should always be polite and helpful.

                   A                         B                    C            D

( ) 4. The computer is very useful today, for example,

                         A                                              B

             the librarian can use it to help you find the books on medicine easily in the library. 

                       C                                                                    D

( ) 5. At one time, there were long queues of people  waiting  outside the ticket offices of CAAC.

                                                                        A          B          C            D

单项选择题 A3/A4型题