Journal Article


Kevin E O'Connor
Maria Auxiliadora Prieto
Gerard Cagney
John P Quinn
John W McGrath
Maciej W Guzik
Pilar Fonseca Garcia
Jasmina Nikodinovic-Runic
William T Casey



up regulation nicotinamide adenine dinucleotide carbon metabolism pseudomonas putida oxidative stress gene deletion protein expression adenosine triphosphate

The effect of polyphosphate kinase gene deletion on polyhydroxyalkanoate accumulation and carbon metabolism in Pseudomonas putida KT2440. (2013)

Abstract The primary enzyme involved in polyphosphate (polyP) synthesis, polyP kinase (ppk), has been deleted in Pseudomonas putida KT2440. This has resulted in a threefold to sixfold reduction in polyhydroxyalkanoate (PHA) accumulation compared with the wild type under conditions of nitrogen limitation, with either temperature or oxidative (H2O2) stress, when grown on glucose. The accumulation of PHA by Δppk mutant was the same as the wild type under nitrogen-limiting growth conditions. There was no difference in polyP levels between wild-type and Δppk strains under all growth conditions tested. In the Δppk mutant proteome, polyP kinase (PPK) was undetectable, but up-regulation of the polyp-associated proteins polyP adenosine triphosphate (ATP)/nicotinamide adenine dinucleotide (NAD) kinase (PpnK), a putative polyP adenosine monophosphate (AMP) phosphotransferase (PP_1752), and exopolyphosphatase was observed. Δppk strain exhibited significantly retarded growth with glycerol as carbon and energy source (42 h of lag period compared with 24 h in wild-type strain) but similar growth to the wild-type strain with glucose. Analysis of gene transcription revealed downregulation of glycerol kinase and the glycerol facilitator respectively. Glycerol kinase protein expression was also downregulated in the Δppk mutant. The deletion of ppk did not affect motility but reduced biofilm formation. Thus, the knockout of the ppk gene has resulted in a number of phenotypic changes to the mutant without affecting polyP accumulation.
Collections Ireland -> University College Dublin -> PubMed

Full list of authors on original publication

Kevin E O'Connor, Maria Auxiliadora Prieto, Gerard Cagney, John P Quinn, John W McGrath, Maciej W Guzik, Pilar Fonseca Garcia, Jasmina Nikodinovic-Runic, William T Casey

Experts in our system

Kevin E O'Connor
University College Dublin
Total Publications: 52
Gerard Cagney
Royal College of Surgeons in Ireland
Total Publications: 54
Jasmina Nikodinovic-Runic
University College Dublin
Total Publications: 19