ARS | Publication request: Poly(hydroxyalkanoate) Synthesis from Various High Volume Industrial Coproducts

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 20, 2007
Publication Date: October 17, 2007
Citation: Ashby, R.D., Solaiman, D., Foglia, T.A. 2007. Poly(hydroxyalkanoate) Synthesis from Various High Volume Industrial Coproducts. Meeting Abstract. #25.

Technical Abstract: In the USA, glycerol, soy molasses and fish byproducts are all produced in large quantities from the biodiesel, soybean processing and Alaskan fishing industries, respectively. In an attempt to help these materials maintain their value and at the same time decrease production costs for poly(3-hydroxyalkanoate) (PHA) polymers, we have developed fermentation systems whereby these coproducts can be used as fermentation substrates in PHA polymer production. Six different species of Pseudomonas (all known PHA producers) were screened for their ability to synthesize PHA from each substrate. At least one of the bacterial species synthesized PHA polymers from each coproduct. Glycerol supported the growth of four different organisms, but P. oleovorans NRRL B-14682 (poly-3-hydroxybutyrate; PHB) and P. corrugata 388 (medium-chain-length PHA; mcl-PHA) were the only two that also produced PHA polymer. The predominant monomers present in the mcl-PHA from P. corrugata included 3-hydroxydecanoic acid (C10:0) and 3-hydroxydodecenoic acid (C12:1). Additionally, increased glycerol media concentrations caused a reduction in the PHB molar mass due to chain end-capping. Soy molasses is high in potentially fermentable carbohydrates (up to 30% w/v). From soy molasses, however, only P. corrugata 388 produced mcl-PHA polymers, consisting primarily of 3-hydroxyoctanoic acid (C8:0), C10:0, 3-hydroxydodecanoic acid (C12:0) and 3-hydroxytetradecenoic acid (C14:1), by utilizing its sucrose component. Crude fish (pollock) oil (in its free fatty acid form) supported growth and polymer production from all six bacterial species. Two of the organisms (P. oleovorans NRRL B-778 and P. oleovorans NRRL B-14682) produced PHB while the other four (P. corrugata 388, P. putida KT2442, P. resinovorans NRRL B-2649 and P. oleovorans NRRL B-14683) synthesized mcl-PHA. The mcl-PHA from P. resinovorans was comprised primarily of C10:0 (53 mol%), while the other mcl-PHA polymers had C8:0 contents approaching 60 mol%. Utilizing these coproducts to produce both PHB and mcl-PHA through fermentation lays the groundwork for new applications (outlets) for these materials, which may ultimately aid in reducing the cost of PHA polymer synthesis and/or result in polymers with unique physical properties.