Abstract
In general, wild-type gram-negative enteric bacteria are not able to utilize D-amino acids as the precursors of respective L-amino acids. We found, however, that an L-histidine auxotroph mutant, TA100, derived from Salmonella typhimurium strain LT 2 and used in the Ames test, showed a biphasic growth curve in the presence of both L- and D-histidine at concentrations of 5 micrograms/ml and 100 micrograms/ml, respectively. L-histidine may be utilized preferentially and then, after a short lag, D-histidine may be utilized. The short lag time is therefore considered to be the time required for induction of such an enzyme that converts D-histidine to L-histidine and for uptake of D-histidine by the bacterial cells.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
