Type

Journal Article

Authors

Kevin E O'Connor
Werner J Blau
Trevor Woods
Ramesh P Babu
Shane T Kenny
Jasmina Nikodinovic

Subjects

Chemistry

Topics
hydrocarbons aromatic metabolism biotransformation pseudomonas putida biomass growth development polyhydroxyalkanoates fermentation chemistry

The conversion of BTEX compounds by single and defined mixed cultures to medium-chain-length polyhydroxyalkanoate. (2008)

Abstract Here, we report the use of petrochemical aromatic hydrocarbons as a feedstock for the biotechnological conversion into valuable biodegradable plastic polymers--polyhydroxyalkanoates (PHAs). We assessed the ability of the known Pseudomonas putida species that are able to utilize benzene, toluene, ethylbenzene, p-xylene (BTEX) compounds as a sole carbon and energy source for their ability to produce PHA from the single substrates. P. putida F1 is able to accumulate medium-chain-length (mcl) PHA when supplied with toluene, benzene, or ethylbenzene. P. putida mt-2 accumulates mcl-PHA when supplied with toluene or p-xylene. The highest level of PHA accumulated by cultures in shake flask was 26% cell dry weight for P. putida mt-2 supplied with p-xylene. A synthetic mixture of benzene, toluene, ethylbenzene, p-xylene, and styrene (BTEXS) which mimics the aromatic fraction of mixed plastic pyrolysis oil was supplied to a defined mixed culture of P. putida F1, mt-2, and CA-3 in the shake flasks and fermentation experiments. PHA was accumulated to 24% and to 36% of the cell dry weight of the shake flask and fermentation grown cultures respectively. In addition a three-fold higher cell density was achieved with the mixed culture grown in the bioreactor compared to shake flask experiments. A run in the 5-l fermentor resulted in the utilization of 59.6 g (67.5 ml) of the BTEXS mixture and the production of 6 g of mcl-PHA. The monomer composition of PHA accumulated by the mixed culture was the same as that accumulated by single strains supplied with single substrates with 3-hydroxydecanoic acid occurring as the predominant monomer. The purified polymer was partially crystalline with an average molecular weight of 86.9 kDa. It has a thermal degradation temperature of 350 degrees C and a glass transition temperature of -48.5 degrees C.
Collections Ireland -> University College Dublin -> PubMed

Full list of authors on original publication

Kevin E O'Connor, Werner J Blau, Trevor Woods, Ramesh P Babu, Shane T Kenny, Jasmina Nikodinovic

Experts in our system

1
Kevin E O'Connor
University College Dublin
Total Publications: 52
 
2
Werner Blau
Trinity College Dublin
Total Publications: 109
 
3
Trevor Woods
Trinity College Dublin
Total Publications: 11
 
4
Ramesh P Babu
University College Dublin
Total Publications: 11
 
5
Shane T Kenny
University College Dublin
Total Publications: 15