Polyhydroxyalkanoate (PHA) Biosynthesis from Whey Lactose |
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| Authors: | Martin Koller Aid Atli? Yolanda Gonzalez-Garcia Christoph Kutschera Gerhart Braunegg |
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| Institution: | 1. Graz University of Technology, Institute of Biotechnology and Biochemical Engineering, Petersgasse 12, 8010 Graz, Austria;2. University of Guadalajara, Chemical Engineering Department, Blvd. Marcelino García 1421, Guadalajara, Jalisco, Mexico |
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| Abstract: | Summary: The potential of three different microbial wild type strains as polyhydroxyalkanoate (PHA) producers from whey lactose is compared. Homopolyester and co-polyester biosynthesis was investigated by the archaeon Haloferax mediterranei and the eubacterial strains Pseudomonas hydrogenovora and Hydrogenophaga pseudoflava. H. mediterranei accumulated 50 wt.-% of poly-3-(hydroxybutyrate-co-6%-hydroxyvalerate) in cell dry mass from hydrolyzed whey without addition of 3-hydroxyvalerate (3HV) precursors (specific productivity qp: 2.9 mg/g h). Using P. hydrogenovora, the final percentage of poly-3-hydroxybutyrate (PHB) amounted to 12 wt.-% (qp: 0.03 g/g h); co-feeding of valeric acid resulted in the production of 12 wt.-%. P-3(HB-co-21%-HV) (qp: 0.02 g/g h). With H. pseudoflava, it was possible to reach 40 wt.-% P-3 (HB-co-5%-HV) on not-hydrolyzed whey lactose plus valeric acid as 3HV precursor (qp: 9.1 mg/g h); on hydrolyzed whey lactose without addition of valeric acid, the strain produced 30 wt.-% of PHB (qp: 0.16 g/g h). The characterization of the isolated biopolyesters completes the study. |
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| Keywords: | biocompatibility biopolymers high-performance polymers polyhydroxyalkanoates whey |
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