title: Aerobic metabolism of mixed carbon sources in sequencing batch reactor under pulse and continuous feeding.
abstract: The aerobic metabolism of a mixture of acetate and starch was studied with main emphasis on their interaction and the effect on their storage as PHB and glycogen, respectively. Pulse feeding strongly increased the storage of both substrates; however, the presence of starch decreased PHB storage whereas the presence of acetate did not affect glycogen storage. Indeed, 13C NMR isotopomer analysis suggested an increase of acetate utilization towards TCA cycle, due to an increased request of ATP production for glycogen biosynthesis regulated by ADP-GlcPPase. This in turn influenced the partition flux for pyruvate synthesis between TCA cataplerosis and glyoxylate shunt. The corresponding reduction of PHB synthesis was in agreement with the competition for HS-CoA between KGDH activity and acetyl-CoA for PHB synthesis pathway. As a practical consequence, bioprocesses for PHA production from volatile fatty acids could be negatively affected from other carbon sources, such as unfermented carbohydrates.
authors.affiliation: Faculty of Civil Engineering, Environmental Engineering Department, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey. asliseyhan3@yahoo.com
authors.forename: Asli S
authors.initials: AS
authors.lastname: Ciggin
authors.forename: Derin
authors.initials: D
authors.lastname: Orhon
authors.forename: Donatella
authors.initials: D
authors.lastname: Capitani
authors.forename: Alfredo
authors.initials: A
authors.lastname: Miccheli
authors.forename: Caterina
authors.initials: C
authors.lastname: Puccetti
authors.forename: Mauro
authors.initials: M
authors.lastname: Majone
mesh_terms: D000085:Acetates / Q000378:metabolism*; D001420:Bacteria, Aerobic / Q000378:metabolism*; D061249:Batch Cell Culture Techniques / Q000379:methods*; D019149:Bioreactors / Q000382:microbiology*; D006003:Glycogen / Q000378:metabolism*; D006885:Hydroxybutyrates / Q000378:metabolism*; D011091:Polyesters / Q000378:metabolism*; D000094122:Polyhydroxybutyrates
chemical_list: D000085:Acetates; D006003:Glycogen; D006885:Hydroxybutyrates; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates