Development of a bioprocess to convert PET derived terephthalic acid and biodiesel derived glycerol to medium chain length polyhydroxyalkanoate

Abstract

Sodium terephthalate (TA) produced from a PET pyrolysis product and waste glycerol (WG) from biodiesel manufacture were supplied to Pseudomonas putida GO16 in a fed-batch bioreactor. Six feeding strategies were employed by altering the sequence of TA and WG feeding. P. putida GO16 reached 8.70 g/l cell dry weight (CDW) and 2.61 g/l PHA in 48 h when grown on TA alone. When TA and WG were supplied in combination, biomass productivity (g/l/h) was increased between 1.3- and 1.7-fold and PHA productivity (g/l/h) was increased 1.8- to 2.2-fold compared to TA supplied alone. The monomer composition of the PHA accumulated from TA or WG was predominantly composed of 3-hydroxydecanoic acid. PHA monomers 3-hydroxytetradeeanoic acid and 3-hydroxytetradecenoic acid were not present in PHA accumulated from TA alone but were present when WG was supplied to the fermentation. When WG was either the sole carbon source or the predominant carbon source supplied to the fermentation the molecular weight of PHA accumulated was lower compared to PHA accumulated when TA was supplied as the sole substrate. Despite similarities in data for the properties of the polymers, PHAs produced with WG present in the PHA accumulation phase were tacky while PHA produced where TA was the sole carbon substrate in the polymer accumulation phase exhibited little or no tackiness at room temperature. The co-feeding of WG to fermentations allows for increased utilisation of TA. The order of feeding of WG and TA has an effect on TA utilisation and polymer properties.

A novel programmable lysozyme-based lysis system in Pseudomonas putida for biopolymer production

“…Commercialized PHAs are currently being produced at industrial scale by KANEKA Corporation (Japan), Biomer (Germany), Bio-on (Italy), and Meridian Inc. (USA). Among the natural PHA-producing industrial strains, Pseudomonas species play a key role as cell factory for the synthesis of a wide array of medium-chain-length PHAs (mcl-PHAs) 6, 7 from various feedstocks such as waste oils 8 , by-products of the sugar, palm, and biodiesel industry 9, 10 . This is due to the high metabolic versatility displayed by Pseudomonas 11 that can cope with the adverse conditions imposed by the substrates used as carbon sources, where some of them are toxic, or even lethal, to other microbial industrial strains like E .…”

“…In recent years, glycerol has emerged as a promising carbon substrate for industrial biotechnological applications given its low cost, high degree of reduction, and increased supply by the biodiesel industry 12 . Pseudomonas putida strains has recently proved to be suitable for converting raw and pure glycerol into mcl-PHAs in batch 9, 13 , Fed-batch 10 , and chemostat cultures 14 . Under nitrogen limiting conditions, P .…”

Production of medium chain length polyhydroxyalkanoate in metabolic flux optimized Pseudomonas putida

“…Pseudomonas species accumulated mcl-PHAs when grown on sodium terephthalate produced from a PET pyrolysis, raw glycerol [18], polystyrene pyrolysis oil, and animal waste lipids [19]. Glucose is still one of the cheapest and most available feedstock for industrial polymer biosynthesis [20].…”

Microbial Conversion of Waste Glycerol from Biodiesel Production into Value-Added Products

“…The highest yield was achieved using 10 g/L of glycerol (0.31 g/g glycerol, 80.4% of the cell dry weight). A waste glycerol supplement can increase the biomass production up to 1.7 fold and PHA accumulation up to 2.2 fold in Pseudomonas putida GO16 (0.11 g/L/h), compared to growth on sodium terephthalate (major plastic waste from pyrolysis of Polyethylene terephthalate) alone [59].…”