title: Metabolic flexibility of D-ribose producer strain of Bacillus pumilus under environmental perturbations.
abstract: The metabolic reaction rate vector is a bridge that links gene and protein expression alterations to the phenotypic endpoint. We present a simple approach for the estimation of flux distribution at key branch points in the metabolic network by using substrate uptake, metabolite secretion rate, and biomass growth rate for transketolase (tkt) deficient Bacillus pumilus ATCC 21951. We find that the glucose-6-phosphate (G6P) and pseudo catabolic/anabolic branch points are flexible in the D: -ribose-producing tkt deficient strain of B. pumilus. The normalized flux through the pentose phosphate pathway (PPP) varied from 1.5 to 86 % under different growth conditions, thereby enabling substantial extracellular accumulation of D: -ribose under certain conditions. Interestingly, the flux through PPP was affected by the extracellular phosphate concentration and dissolved oxygen concentration. This metabolic flexibility may have been the underlying reason for this strain being selected from thousands of others in a screening for D: -ribose producers conducted in the 1970s.
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, 400076, Mumbai, India.
authors.forename: Rajesh K
authors.initials: RK
authors.lastname: Srivastava
authors.forename: Soumen K
authors.initials: SK
authors.lastname: Maiti
authors.forename: Debasish
authors.initials: D
authors.lastname: Das
authors.forename: Prashant M
authors.initials: PM
authors.lastname: Bapat
authors.forename: Kritika
authors.initials: K
authors.lastname: Batta
authors.forename: Mani
authors.initials: M
authors.lastname: Bhushan
authors.forename: Pramod P
authors.initials: PP
authors.lastname: Wangikar
mesh_terms: D001407:Bacillus / Q000145:classification / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D018533:Biomass; D053858:Metabolic Networks and Pathways; D010100:Oxygen / Q000378:metabolism; D010427:Pentose Phosphate Pathway; D012266:Ribose / Q000096:biosynthesis*; D014174:Transketolase / Q000235:genetics / Q000378:metabolism
chemical_list: D012266:Ribose; D014174:Transketolase; D010100:Oxygen