Abstract
‘The addition of 0.2 % vitamin-free Casamino acids to the medium resulted in colonies arising at a frequency of ∼4×10−8. The component of the Casamino acids which allowed thiamine-independent revertants to arise was methionine’.
Microbiology (2010), 156, part 3, 950–959.
The following changes have been made to the online version of the above paper.
1. Introduction, page 951, first column, line 2
The citations on this line have been replaced with ‘Hove-Jensen, 1985; Post et al., 1991’.
2. Methods, page 951, second column, line 18, ‘Spontaneous mutations...∼4×108’., replace with:
‘Spontaneous mutations allowing growth arose at a frequency of ∼4×10−8’.
3. Results, page 953, second column, line 4, beginning with ‘The addition of...’, replace with:
‘The addition of 0.2 % vitamin-free Casamino acids to the medium resulted in colonies arising at a frequency of ∼4×10−8. The component of the Casamino acids which allowed thiamine-independent revertants to arise was methionine’.
4. Table 2, page 953
In Table 2, allele prsA503 has a change of ‘G–12T’ and not ‘G12T’.
5. Discussion, page 958, first column, line 27, beginning ‘Additionally...’, replace with:
‘Additionally, this study is a new report of a positive selection for mutations that negatively affect the enzymic activity of PrsA’.
6. References
(a) The following reference has been added to the References list:
Hove-Jensen, B. (1985). Cloning and characterization of the prs gene encoding phosphoribosylpyrophosphate synthetase of Escherichia coli. Mol Gen Genet 201, 269–276.
(b) The following reference has been deleted from the References list:
Larsen et al., 1999.