Increasing the yield of MCL-PHA from nonanoic acid by co-feeding glucose during the PHA accumulation stage in two-stage fed-batch fermentations of Pseudomonas putida KT2440.
A method was developed to increase the yield of MCL-PHA from nonanoic acid in the PHA accumulation phase. Pseudomonas putida KT2440 was grown on glucose until ammonium-limitation was imposed. In the second (accumulation) stage, either glucose, nonanoic acid, or a mixture of these carbon and energy sources was supplied. Since the medium-chain-length poly-3-hydroxyalkanoate (MCL-PHA) subunits produced are unique for each carbon source, their relative contribution to PHA yield could be calculated. Y(C7+C9)/NA was 0.254 mol mol(-1) during PHA synthesis from nonanoic acid. Y(C8+C10)/G was only 0.057 mol mol(-1) during PHA synthesis from glucose. When nonanoic acid and glucose were fed together, Y(C7+C8)/NA almost doubled to 0.450 mol mol(-1) while Y(C8+C10)/G decreased to 0.011 mol mol(-1). These results demonstrate that substantial savings can be obtained by feeding glucose with substrates that are good for PHA production but much more expensive than glucose.
Sun
Zhiyong
Z
Department of Chemical Engineering, Queen's University, Kingston, Ontario, Canada K7L 3N6.
Ramsay
Juliana A
JA
Guay
Martin
M
Ramsay
Bruce
B
D001709:Biotechnology / Q000379:methods*; D002244:Carbon; D005227:Fatty Acids / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism*; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis*; D016958:Pseudomonas putida / Q000378:metabolism*
D005227:Fatty Acids; D054813:Polyhydroxyalkanoates; D002244:Carbon; C008776:pelargonic acid; D005947:Glucose