Metabolite profiling of the cold adaptation ofPseudomonas putidaKT2440 and cold‐sensitive mutants

Abstract

Free-living bacteria such as Pseudomonas putida are frequently exposed to temperature shifts and nonoptimal growth conditions. We compared the transcriptome and metabolome of the cold adaptation of P. putida KT2440 and isogenic cold-sensitive transposon mutants carrying transposons in their cbrA, cbrB, pcnB, vacB, and bipA genes. Pseudomonas putida changes the mRNA expression of about 43% of all annotated open reading frames during this initial phase of cold adaptation, but only a small number of 6-93 genes were differentially expressed at 10 C between the wild-type strain and the individual mutants. The spectrum of metabolites underwent major changes during cold adaptation particularly in the mutants. Both the KT2440 strain and the mutants increased the levels of the most abundant sugars and amino acids which were more pronounced in the coldsensitive mutants. All mutants depleted their pools for core metabolites of aromatic and sugar metabolism, but increased their pool of polar amino acids which should be advantageous to cope with the cold stress. PSYSMO 'Towards a quantum increase in the performance of P. putida as the cell factory of choice for white biotechnology,' project 3: Key determinants of abiotic stress response of P. putida KT2440.

The Regulatory Functions of σ54 Factor in Phytopathogenic Bacteria

“…Furthermore, CbrAB controls the expression of alginate biosynthetic genes and rsmA . It is also required to accumulate the sigma factor RpoS and core metabolites of aromatic and sugar metabolism [ 85 , 86 ]. Importantly, CbrAB and the master nitrogen regulator NtrBC directly control C/N homeostasis by regulating the transcription of histidine utilization genes ( hut ) [ 87 ].…”

“…In succinate-depleted media, CbrAB activates hut transcription while derepressing the translation of hut mRNA mediated by the Crc/Hfq complex, which is sequestrated by the CbrAB-activated ncRNAs (CrcY and CrcZ). Interestingly, deletions of cbrA and cbrB impaired swimming and swarming motility, decreased T3SS-associated genes expression, and enhanced the sensitivity to cold [ 86 , 88 ]. This indicated that the RpoN/CbrAB–CrcYZ–Crc/Hfq regulatory cascade system controls more important phenotypes beyond carbon and nitrogen assimilation.…”