Introductory Microbiology

Mutation

• Mutation is an inherited change in the base sequence of the nucleic acid comprising the genome of an organism. A strain carrying such change is called as mutant strain and non-mutated which was isolated from natural environment is called as wild type strain.
• Genotype of an organism for particular character can be written as three lettered lower case with italic letters following a capital letter. Ex. lac Z refers the gene which codes the enzyme ?-galactosidase. The protein transcripted from this can be written as normal letters starting with capital letter. For the above gene, the protein may be written as Lac Z. The phenotype of the organism for this gene can be written as Lac Z+ for presence and Lac Z- for absence.