title: Partial bioenergetic characterization of Gluconacetobacter xylinum cells released from cellulose pellicles by a novel methodology.
abstract: OBJECTIVE
  Gluconacetobacter xylinum is well known for its ability to produce large amounts of cellulose, however, little is known about its cell physiology. Our goal was to study the respiratory metabolism and components of the respiratory system of this bacterium in static cultures. To reach our goal, a medium formulation had to be designed to improve cell growth and cellulose production together with a novel method for the recovery of cells from cellulose pellicles.
  
  
  RESULTS
  Successive modifications of a nutrient medium improved G. xylinum cell growth 4.5-fold under static culture conditions. A blender homogenization procedure for the releasing of cells from the cellulose matrix gave a high yield of cells recovered. Respiratory activities of purified cells were greatly stimulated by exogenous substrates and showed to be resistant to KCN. Unexpectedly, exogenous NADH was oxidized at high rates. Cytochromes a, b, c and d were identified after spectral analyses.
  
  
  CONCLUSIONS
  Partial bioenergetic characterization of G. xylinum cells allowed us to propose a scheme for its respiratory system. In addition, the growth medium for biomass production and the procedure for the efficient recovery of cells from cellulose pellicles were significantly improved.
  
  
  CONCLUSIONS
  This work provides the first-ever bioenergetic characterization of G. xylinum grown in static cultures. In addition, a novel methodology to obtain purified cells in suitable quantities for biochemical research is described.
authors.affiliation: Instituto de Fisiología Celular, Universidad Nacional Autonoma de Mexico, Mexico.
authors.forename: J L
authors.initials: JL
authors.lastname: Chávez-Pacheco
authors.forename: S
authors.initials: S
authors.lastname: Martínez-Yee
authors.forename: M L
authors.initials: ML
authors.lastname: Contreras
authors.forename: S
authors.initials: S
authors.lastname: Gómez-Manzo
authors.forename: J
authors.initials: J
authors.lastname: Membrillo-Hernández
authors.forename: J E
authors.initials: JE
authors.lastname: Escamilla
mesh_terms: D002248:Carbon Monoxide / Q000378:metabolism; D002482:Cellulose; D003470:Culture Media; D003580:Cytochromes / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D041822:Gluconacetobacter xylinus / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning / Q000379:methods; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D011190:Potassium Cyanide / Q000494:pharmacology
chemical_list: D003470:Culture Media; D003580:Cytochromes; D004791:Enzyme Inhibitors; D009243:NAD; D002248:Carbon Monoxide; D002482:Cellulose; D011190:Potassium Cyanide