title: Physiological and proteomic adaptation of "Aromatoleum aromaticum" EbN1 to low growth rates in benzoate-limited, anoxic chemostats.
abstract: "Aromatoleum aromaticum" EbN1 was cultivated at different growth rates in benzoate-limited chemostats under nitrate-reducing conditions. Physiological characteristics, proteome dynamics, phospholipid-linked fatty acid (PLFA) composition, and poly(3-hydroxybutyrate) (PHB) content were analyzed in steady-state cells at low (μ(low)) (0.036 h(-1)), medium (μ(med)) (0.108 h(-1)), and high (μ(high)) (0.180 h(-1)) growth rates. A positive correlation to growth rate was observed for cellular parameters (cell size, and DNA and protein contents). The free energy consumed for biomass formation steadily increased with growth rate. In contrast, the energy demand for maintenance increased only from μ(low) to μ(med) and then remained constant until μ(high). The most comprehensive proteomic changes were observed at μ(low) compared to μ(high). Uniformly decreased abundances of protein components of the anaerobic benzoyl coenzyme A (benzoyl-CoA) pathway, central carbon metabolism, and information processing agree with a general deceleration of benzoate metabolism and cellular processes in response to slow growth. In contrast, increased abundances were observed at μ(low) for diverse catabolic proteins and components of uptake systems in the absence of the respective substrate (aromatic or aliphatic compounds) and for proteins involved in stress responses. This potential catabolic versatility and stress defense during slow growth may be interpreted as preparation for future needs.
authors.affiliation: Institute of Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Trautwein
authors.forename: Sven
authors.initials: S
authors.lastname: Lahme
authors.forename: Lars
authors.initials: L
authors.lastname: Wöhlbrand
authors.forename: Christoph
authors.initials: C
authors.lastname: Feenders
authors.forename: Kai
authors.initials: K
authors.lastname: Mangelsdorf
authors.forename: Jens
authors.initials: J
authors.lastname: Harder
authors.forename: Alexander
authors.initials: A
authors.lastname: Steinbüchel
authors.forename: Bernd
authors.initials: B
authors.lastname: Blasius
authors.forename: Richard
authors.initials: R
authors.lastname: Reinhardt
authors.forename: Ralf
authors.initials: R
authors.lastname: Rabus
mesh_terms: D000222:Adaptation, Physiological; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001431:Bacteriological Techniques; D001565:Benzoates / Q000737:chemistry / Q000378:metabolism*; D020562:Betaproteobacteria / Q000145:classification / Q000254:growth & development* / Q000502:physiology*; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane; D004269:DNA, Bacterial; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects* / Q000502:physiology; D009566:Nitrates / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D020543:Proteome; D013312:Stress, Physiological; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D001565:Benzoates; D002352:Carrier Proteins; D004269:DNA, Bacterial; D009566:Nitrates; D020543:Proteome; D010100:Oxygen