Factors Affecting Poly(3-hydroxybutyrate) Production from Oil Palm Frond Juice byCupriavidus necator(CCUG52238T)

Abstract

Factors influencing poly(3-hydroxybutyrate) P(3HB) production by Cupriavidus necator CCUG52238T utilizing oil palm frond (OPF) juice were clarified in this study. Effects of initial medium pH, agitation speed, and ammonium sulfate (NH4)2SO4 concentration on the production of P(3HB) were investigated in shake flasks experiments using OPF juice as the sole carbon source. The highest P(3HB) content was recorded at pH 7.0, agitation speed of 220 rpm, and (NH4)2SO4 concentration at 0.5 g/L. By culturing the wild-type strain of C. necator under the aforementioned conditions, the cell dry weight (CDW) and P(3HB) content obtained were 9.31 ± 0.13 g/L and 45 ± 1.5 wt.%, respectively. This accounted for 40% increment of P(3HB) content compared to the nonoptimized condition. In the meanwhile, the effect of dissolved oxygen tension (DOT) on P(3HB) production was investigated in a 2-L bioreactor. Highest CDW (11.37 g/L) and P(3HB) content (44 wt.%) were achieved when DOT level was set at 30%. P(3HB) produced from OPF juice had a tensile strength of 40 MPa and elongation at break of 8% demonstrated that P(3HB) produced from renewable and cheap carbon source is comparable to those produced from commercial substrate.

Oil palm frond as a sustainable and promising biomass source in Malaysia: A review

“…OPF can be pressed into fresh juice to serve as renewable and sustainable substrate for the production of biodegradable thermoplastic polyester, i.e., poly(3-hydroxybutyrate) (P(3HB)) [80]. The presence of mineral and nutrients (fructose, sucrose, and glucose) in the OPF juice encouraged the bacterial growth during fermentation.…”

Non-solvent-based pretreatment of poly(3-hydroxybutyrate) for improved bio-based crotonic acid production

“…One mL of trace element was added aer sterile ltration. 29 OPF juice was used as carbon source while mixture of synthetic sugars (glucose, sucrose and fructose) having similar concentration with OPF juice was used as control carbon source. In order to study effect of OPF juice heating on PHB production, heat-sterilized OPF juice was used and compared with lter-sterilized OPF juice.…”

“…pH was controlled at pH 6.8 with 10% H 2 SO 4 solution and 25% NH 4 OH solution, while dissolved oxygen level was maintained at 20% saturation throughout fermentation by using cascade mode and supplied with air at 1.0 vvm. 29 Sugar concentration was measured by using DNS method. Cells containing PHB were harvested by centrifuge with 10 000Âg for 10 min at 4 C in a Sorvall Legend RT+ Centrifuge and lyophilized using freezedryer.…”

Upgrading of Oil Palm Biomass to Value-Added Products

“…PHB content reached about 60 % in cell dry weight and 12.48 g/L PHB was obtained from EFB hydrolyzate containing 60 g/L sugar with PHB productivity of 0.260 g/L/h. Unlike EFB, oil palm frond (OPF) contains free sugars and OPF juice can be obtained by pressing the OPF using a sugarcane pressing machine Mohd Zahari et al 2012 ). Such OPF juice contained a mixture of sugars such as glucose, sucrose, and fructose, where the glucose accounts for 70 %.…”