Biodegradable Latexes from Animal-Derived Waste: Biosynthesis and Characterization of mcl-PHA accumulated by Ps. citronellolis
| Autor: | Martin Mittelbach, Sigurd Schober, Martin Koller, Eva Maria Rechberger, Marek Kowalczuk, Grazyna Adamus, Michał Kwiecień, Alexander Muhr, Margaretha Schiller, Anna Salerno, Katharina Strohmeier, Angelika Reiterer |
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| Rok vydání: | 2013 |
| Předmět: |
0106 biological sciences
Thermogravimetric analysis Polymers and Plastics General Chemical Engineering 01 natural sciences Biochemistry Polyhydroxyalkanoates 03 medical and health sciences Crystallinity Differential scanning calorimetry 010608 biotechnology Materials Chemistry Environmental Chemistry Organic chemistry 030304 developmental biology 0303 health sciences biology Chemistry Thermal decomposition General Chemistry biology.organism_classification 6. Clean water Fermentation Pseudomonas citronellolis Glass transition Nuclear chemistry |
| Popis: | Background mcl -PHA biosynthesis by Pseudomonas citronellolis from tallow-based biodiesel as inexpensive carbon feed stock was accomplished. Fermentation protocols, kinetic analysis, an efficient product recovery strategy, and a detailed product characterization are presented. Results A maximum specific growth rate, μ max. of 0.10 and 0.08 h −1 , respectively, was achieved in two different fermentation set-ups. Volumetric productivity for mcl -PHA amounted to 0.036 g/L h and 0.050 g/L h, final intracellular PHA contents calculated from the sum of active biomass and PHA to 20.1 and 26.6 wt.%, respectively. GC-FID analysis showed that the obtained biopolyester predominantly consists of 3-hydroxyoctanoate and 3-hydroxydecanoate, and, to a minor extent, 3-hydroxydodecanoate, 3-hydroxynonanoate, 3-hydroxyhexanoate, and 3-hydroxyheptanoate monomers. This was confirmed by 1 H- and 13 C NMR, also evidencing the occurrence of low quantities of unsaturated and 3-hydroxyvalerate building blocks. High purity of the recovered materials was proofed by elemental analysis. Regarding the results from thermogravimetric analysis, differential scanning calorimetry and molecular mass determination, results were in a range typical for this type of PHA (1st fermentation: decomposition temperature T d = 296 °C, peak of melting range T m = 48.6 °C; glass transition temperature T g = −46.9 °C, degree of crystallinity X c = 12.3%, M w = 66,000, M n = 35,000, dispersity index P i = 1.9; 2nd fermentation: T d = 295 °C, T m = 53.6 °C, T g = -43.5 °C, X c = 10.4%, M w = 78,000, M n = 196,000, P i = 2.5). |
| Databáze: | OpenAIRE |
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