A new E. coli phage was isolated in Brisbane from sewage and work was conducted

Question

A new E. coli phage was isolated in Brisbane from sewage and work was conducted to characterise it as a virulent (lytic) or temperate phage (lysogenic). A scientist conducted a transduction trial with one donor strain and a range of different recipient strains. When complete, he noticed that one particular gene, the tub gene, was transduced from the donor to the recipient strain with much higher frequency than any of the other chromosomal markers. He wrote in his lab book “The phage appears to be lytic”.

(a)    Do you think he is right?

(b)      Can you propose a mechanism for the high-level transduction of the tub marker? You may draw diagrams as part of your answer.

Explanation / Answer

As E.coli phage was isolated from sewage.It will go through many infection cycle and cause lysis to E.coli.Now here the Scientist considered two cycle of infection which are lytic and lysogenic.The bacteriophages which are virulent they enter the host cell and destroy it rapidly through lysis.And the bacteriophage which are for temperate lyse the host cell lysogenize the host.

Now the second question is about whether the Scientist is right or wrong.Then the Scientist is right because the tub gene prevents lysis of cell by causing lysozyme enzyme.

Mechanism:-

Firstly DNA are injected by phage

Secondly the host DNA is breakdown by phage enzyme.

Thirdly and fourthly there are creation of new cells which includes phage and host DNA.

In Fifth and sixth stage there is transducing phage inserts donor DNA.

At Seventh stage the chromosome is a recipients which includes donor DNA in the process of recombination.

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