title: Polyhydroxybutyrate accumulation by a Serratia sp.
abstract: A strain of Serratia sp. showed intracellular electron-transparent inclusion bodies when incubated in the presence of citrate and glycerol 2-phosphate without nitrogen source following pre-growth under carbon-limitation in continuous culture. About 1.3 mmol citrate were consumed per 450 mg biomass, giving a calculated yield of maximally 55% of stored material per g of biomass dry wt. The inclusion bodies were stained with Sudan Black and Nile Red (NR), suggesting a lipid material, which was confirmed as polyhydroxybutyrate (PHB) by analysis of molecular fragments by GC and by FTIR spectroscopy of isolated bio-PHB in comparison with reference material. Multi-parameter flow cytometry in conjunction with NR fluorescence, and electron microscopy, showed that not all cells contained heavy PHB bodies, suggesting the potential for increasing the overall yield. The economic attractiveness is enhanced by the co-production of nanoscale hydroxyapatite (HA), a possible high-value precursor for bone replacement materials.
authors.affiliation: School of Dentistry, University of Birmingham, St Chad's Queensway, Birmingham, UK.
authors.forename: Harriet
authors.initials: H
authors.lastname: Lugg
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Sammons
authors.forename: Peter M
authors.initials: PM
authors.lastname: Marquis
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hewitt
authors.forename: Ping
authors.initials: P
authors.lastname: Yong
authors.forename: Marion
authors.initials: M
authors.lastname: Paterson-Beedle
authors.forename: Mark D
authors.initials: MD
authors.lastname: Redwood
authors.forename: Artemis
authors.initials: A
authors.lastname: Stamboulis
authors.forename: Mitra
authors.initials: M
authors.lastname: Kashani
authors.forename: Mike
authors.initials: M
authors.lastname: Jenkins
authors.forename: Lynne E
authors.initials: LE
authors.lastname: Macaskie
mesh_terms: D002849:Chromatography, Gas; D019343:Citric Acid / Q000378:metabolism; D017886:Durapatite / Q000378:metabolism*; D006885:Hydroxybutyrates / Q000302:isolation & purification / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D009584:Nitrogen / Q000378:metabolism; D012705:Serratia / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D006885:Hydroxybutyrates; D019343:Citric Acid; D017886:Durapatite; D009584:Nitrogen