Saponified palm kernel oil and its major free fatty acids as carbon substrates for the production of polyhydroxyalkanoates in Pseudomonas putida PGA1

Non-Edible Vernonia galamensis Oil and Mixed Bacterial Cultures for the Production of Polyhydroxyalkanoates

“…cultivated on rice, canola, sunflower, soybean, corn and hydrolyzed linseed oils [6,18]. Polymer accumulation, indicated by Nile blue A (Nile blue sulphate, basic blue) is consistent with previous reports and was a good indicator since stained PHA granules are easily identifiable by their characteristic orange fluorescence [16,47]. Neutral lipids do not affect identification of PHA since these lipids are liquids at the staining temperature (55°C) and have no affinity for Nile red (the oxidized form of Nile blue); therefore, cell membranes and other lipid containing cell components do not absorb enough dye to yield a detectable fluorescence at a wavelength of 460 nm [46].…”

“…The utilization of substrates such as plant oils may provide the solution since they contain more carbon atoms (compared to glucose), generate PHA with higher molecular masses and may produce a theoretical yield coefficient of 0.65 to 0.98 g PHA/g plant oil, versus 0.32-0.48 g PHA/g glucose [13][14][15][16][17]. Similarly, a high percentage of PHA has been generated using edible oils; therefore, non-edibles such as Vernonia galamensis oil may be a competitive alternative [14,[18][19][20].…”

Plant Oils and Products of Their Hydrolysis as Substrates for Polyhydroxyalkanoate Synthesis

“…P. chlororaphis 555 grew to the highest biomass and produced the highest amount of PHA on fatty acids from OO (0.94 g L -1 , 39 %). In another study, Pseudomonas putida PGA1, was grown on saponified palm kernel oil achieving similar biomass yields and PHA content to that reported here 49 . However, to the best of our knowledge, there have been no reports of Pseudomonas putida strains grown directly on any of the other saponified oil fatty acid mixtures used in this study.…”

“…However, in this study, saponification was used to represent fatty acid production, as this is more appropriate for a laboratory setting due to technical and mechanical constraints 20 . Oleic acid prices in 2014 were significantly higher than most raw oil prices at approximately $1800/mt, however, it is true that crude fatty acid mixtures would certainly be cheaper to produce than purified single fatty acids, as no distillation is required, and may also produce PHA with different properties to that produced on single fatty acids 10,21 . There has been a limited number of reports of the use of saponified fatty acids for mcl-PHA production.…”

“…There has been a limited number of reports of the use of saponified fatty acids for mcl-PHA production. Saponified palm kernel oil has been used to produce mcl-PHA (3 g L -1 CDW 37 % PHA) in Pseudomonas putida PGA1 21,22 . Mcl-PHA has been accumulated by Pseudomonas aeruginosa (3.5-5.5 g L -1 CDW, 66.1 % PHA) from waste free fatty acids from soybean oil 13 and from saponified waste palm oil by Pseudomonas sp G101 (5.2 g L -1 CDW, 42 % PHA) 23 .…”