Mathematical analysis of catabolic function loss in a population of Pseudomonas putida mt-2 during non-limited growth on benzoate.
Pseudomonas putida mt-2, harbouring the TOL plasmid PWW0, was grown continuously on benzoate in a phauxostat at a non-limited rate. The gradual decrease in the population carrying the complete TOL plasmid was caused predominantly by a growth-rate advantage of spontaneous mutants carrying a partially deleted plasmid (TOL- cells). The growth-rate difference (v) was quantified both by measuring the increase in the dilution rate (from 0.68 to 0.79 h-1; v = 0.11 h-1) and by mathematical analysis of the ingrowth of TOL- cells (v = 0.12 h-1). The latter procedure also established that the segregation rate was of the order of magnitude 10(-5) h-1. Similar values for the growth-rate advantage and the segregation rate were found when both benzoate and succinate were present in non-limiting concentrations. It is suggested that the growth-rate disadvantage of the wild-type strain is caused by inhibitory effects of an intermediate in the degradation of benzoate via the plasmid-encoded meta-pathway.
Laboratory for Waste Materials and Emissions, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
W A
WA
Duetz
M K
MK
Winson
J G
JG
van Andel
P A
PA
Williams
D001565:Benzoates / Q000378:metabolism*; D019817:Benzoic Acid; D001673:Biodegradation, Environmental; D003470:Culture Media; D008433:Mathematics; D010957:Plasmids; D011549:Pseudomonas / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013386:Succinates / Q000378:metabolism; D019802:Succinic Acid; D014050:Toluene / Q000378:metabolism
D001565:Benzoates; D003470:Culture Media; D013386:Succinates; D014050:Toluene; D019817:Benzoic Acid; D019802:Succinic Acid