Dealing with salinity extremes and nitrogen limitation – an unexpected strategy of the marine bacterium Dinoroseobacter shibae

Abstract

SummaryHaving the right coping strategy for changes in osmolarity or desiccation is essential for the survival of every cell. So far, nothing is known about compatible solutes and the salt adaptation of the marine Rhodobacteraceae. The family member Dinoroseobacter shibae DFL12T is shown here to form the compatible solutes a-glucosylglycerol (GG) and aglucosylglycerate (GGA). To our knowledge, this is the first experimental evidence for GGA formation within the a-proteobacteria. Together with glutamate and putrescine, these substances enable good growth in salinity ranging from 0.3% to 5%. A salinity of 5% leads to a biomass share of 7.6% of compatible solutes and the very low salt level of 0.3% results in an 18-fold increased putrescine concentration compared with environmental conditions. Additionally, the substitution of glutamate by GGA has been shown during exposure to nitrogen limitation and in the stationary growth phase of the organism. Salt shock transcriptome analysis of D. shibae has revealed the essential role of its 153 kb chromid, which carries the genes for GG biosynthesis and several transport and exchange systems. Within the family of Rhodobacteraceae, the genomic capability of forming GG and GGA is strictly restricted to marine family members.

Complete Genome Sequence of the Plant Growth-Promoting BacteriumHartmannibacter diazotrophicusStrain E19T

“…The E19 T genome carries heat shock genes dnaJ , dnaK , groES , groEL , htpG , htpX , hspQ , grpE , and ibpA and the cold shock gene cspA ( Table). Moreover, the clpB gene, a heat shock protein, specified to be upregulated during salt stress in marine bacteria [47] is also contained. The E19 T genome carries CDSs encoding for peroxidases, superoxidase, and glutathione S-transferase ( Table).…”

Fixation of CO2 using the ethylmalonyl‐CoA pathway in the photoheterotrophic marine bacterium Dinoroseobacter shibae

“…The up‐regulation of eda , edd and Dshi_1683 and consistently, the increased concentrations of 6‐phosphogluconate and dihydroxyacetone phosphate are indicating an enhanced glucose breakdown, which leads to a replenishment of the direct precursor of ribose‐5‐phosphate. The transcription of these genes might be stress‐induced, as similar effects were observed during osmotic stress in D. shibae (Kleist et al ., ) and nitrogen and carbon starvation in E. coli (Murray and Conway, ).…”

Pelagibaca bermudensis promotes biofuel competence of Tetraselmis striata in a broad range of abiotic stressors: dynamics of quorum-sensing precursors and strategic improvement in lipid productivity

“…In fact, the cells of P. bermudensis that are lysed may also provide metabolic nutrients to the microalgae. Many of these metabolites are osmolytes and phytohormones, which potentially regulate the membrane integrity of the microalgal cells as well as alter or mitigate the intracellular stress levels [ 41 , 42 ].…”