Application of Immersed Membrane Bioreactor for Semi-Continuous Production of Polyhydroxyalkanoates from Organic Waste-Based Volatile Fatty Acids

• Volatile fatty acids (VFAs) appear to be an economical carbon feedstock for the cost-effective production of polyhydroxyalkanoates (PHAs). The use of VFAs, however, could impose a drawback of substrate inhibition at high concentrations, resulting in low microbial PHA productivity in batch cultivations. In this regard, retaining high cell density using immersed membrane bioreactor (iMBR) in a (semi-) continuous process could enhance production yields. In this study, an iMBR with a flat-sheet membrane was applied for semi-continuous cultivation and recovery of Cupriavidus necator in a bench-scale bioreactor using VFAs as the sole carbon source. The cultivation was prolonged up to 128 h under an interval feed of 5 g/L VFAs at a dilution rate of 0.15 (d−1), yielding a maximum biomass and PHA production of 6.6 and 2.8 g/L, respectively. Potato liquor and apple pomace-based VFAs with a total concentration of 8.8 g/L were also successfully used in the iMBR, rendering the highest PHA content of 1.3 g/L after 128 h of cultivation. The PHAs obtained from both synthetic and real VFA effluents were affirmed to be poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with a crystallinity degree of 23.8 and 9.6%, respectively. The application of iMBR could open an opportunity for semi-continuous production of PHA, increasing the feasibility of upscaling PHA production using waste-based VFAs. 

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Industriell bioteknik -- Annan industriell bioteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Industrial Biotechnology -- Other Industrial Biotechnology (hsv//eng)

Nyckelord

biopolymer

immersed membrane reactor

polyhydroxyalkanoates

volatile fatty acids

Bioconversion

Bioreactors

Carbon

Cost effectiveness

Crystallinity

Effluents

Carbon feedstock

Continuous production

Cost-effective production

Immersed membrane

Immersed membrane bioreactors

Membrane reactor

Organic wastes

Semi-continuous

Biopolymers

Resource Recovery

Resursåtervinning

Resource Recovery

Resursåtervinning

Publikations- och innehållstyp

ref (ämneskategori)

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