Polyhydroxybutyrate accumulation by a Serratia sp.
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.
Lugg
Harriet
H
School of Dentistry, University of Birmingham, St Chad's Queensway, Birmingham, UK.
Sammons
Rachel L
RL
Marquis
Peter M
PM
Hewitt
Christopher J
CJ
Yong
Ping
P
Paterson-Beedle
Marion
M
Redwood
Mark D
MD
Stamboulis
Artemis
A
Kashani
Mitra
M
Jenkins
Mike
M
Macaskie
Lynne E
LE
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
D006885:Hydroxybutyrates; D019343:Citric Acid; D017886:Durapatite; D009584:Nitrogen