title: Fruit pomace and waste frying oil as sustainable resources for the bioproduction of medium-chain-length polyhydroxyalkanoates.
abstract: Medium-chain-length polyhydroxyalkanoates (mcl-PHAs) are biobased and biodegradable alternatives to petrol-derived polymers, whose break-through has been prevented by high production cost. Therefore we investigated whether wastes from the food industry (nine types of fruit pomace including apricots, cherries and grapes, and waste frying oil) could replace the costly sugars and fatty acids typically used as carbon substrates for the bacterial fermentations. A selection of enzyme preparations was tested for converting the residual polysaccharides from the pomaces into fermentable monosaccharides. From the pomace of apricots, cherries and Solaris grapes, 47, 49 and 106gL(-1) glucose were recovered, respectively. Solaris grapes had the highest sugar content whereas apricots contained the fewest growth inhibitors. These two pomaces were assessed for their suitability to produce mcl-PHA in bioreactor. A 2-step fermentation was established with Pseudomonas resinovorans, hydrolyzed pomace as growth substrate and WFO as mcl-PHA precursor. Solaris grapes proved to be a very promising growth substrate, resulting in the production of 21.3gPHA(Lpomace)(-1) compared to 1.4g PHA (L pomace)(-1) for apricots. Finally, capillary zone electrophoresis analyses allowed monitoring of sugar and organic acid uptake during the fermentation on apricots, which led to the discovery of reverse diauxie in P. resinovorans.
authors.affiliation: University of Applied Sciences and Arts Western Switzerland Valais (HES-SO Valais-Wallis), Institute of Life Technologies, Route du Rawyl 47, 1950 Sion, Switzerland.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Follonier
authors.affiliation: University of Applied Sciences and Arts Western Switzerland Valais (HES-SO Valais-Wallis), Institute of Life Technologies, Route du Rawyl 47, 1950 Sion, Switzerland.
authors.forename: Miriam S
authors.initials: MS
authors.lastname: Goyder
authors.affiliation: Changins, Route de Duillier 50, Case postale 1148, 1260 Nyon 1, Switzerland.
authors.forename: Anne-Claire
authors.initials: AC
authors.lastname: Silvestri
authors.affiliation: University of Applied Sciences and Arts Western Switzerland Valais (HES-SO Valais-Wallis), Institute of Life Technologies, Route du Rawyl 47, 1950 Sion, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Crelier
authors.affiliation: University of Applied Sciences and Arts Western Switzerland Valais (HES-SO Valais-Wallis), Institute of Life Technologies, Route du Rawyl 47, 1950 Sion, Switzerland.
authors.forename: Franka
authors.initials: F
authors.lastname: Kalman
authors.affiliation: Changins, Route de Duillier 50, Case postale 1148, 1260 Nyon 1, Switzerland.
authors.forename: Roland
authors.initials: R
authors.lastname: Riesen
authors.affiliation: University of Applied Sciences and Arts Western Switzerland Valais (HES-SO Valais-Wallis), Institute of Life Technologies, Route du Rawyl 47, 1950 Sion, Switzerland. Electronic address: manfred.zinn@hevs.ch.
authors.forename: Manfred
authors.initials: M
authors.lastname: Zinn
mesh_terms: D001673:Biodegradation, Environmental; D019149:Bioreactors; D005285:Fermentation; D005638:Fruit / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis*; D011549:Pseudomonas / Q000378:metabolism; D014866:Waste Products
chemical_list: D010938:Plant Oils; D054813:Polyhydroxyalkanoates; D014866:Waste Products
keywords: Capillary electrophoresis; Enzymatic hydrolysis; Polyhydroxyalkanoate; Pomace; Waste frying oil