Potassium deficiency results in accumulation of ultra-high molecular weight poly-β-hydroxybutyrate in a methane-utilizing mixed culture
Open Access
- 1 October 2008
- journal article
- Published by Oxford University Press (OUP) in Journal of Applied Microbiology
- Vol. 105 (4), 1054-1061
- https://doi.org/10.1111/j.1365-2672.2008.03831.x
Abstract
To investigate the effect of various single nutrient deficiencies on poly-beta-hydroxybutyrate (PHB) biosynthesis in a methane-utilizing mixed culture (dominant species Methylocystis sp. GB 25 DSM 7674). Poly-beta-hydroxybutyrate accumulation experiments were performed in 7 and 70 l bioreactors and initiated by potassium, sulfur or iron deficiency. After 24 h the PHB content reached levels of 33.6%, 32.6% and 10.4% respectively. Interestingly a polymer with an ultra-high average-weight molecular weight (M(w)) of 3.1 MDa was accumulated under potassium-limited conditions. When sulfur and iron were lacking M(w) were lower by 20.6 and 41.6%. Potassium-deficiency experiments were furthermore characterized by a maximum specific PHB formation rate 0.08 g g(-1)residual biomass (R) h(-1) and a yield coefficient of 0.45 g PHB g(-1) CH(4). Biosynthesis of an ultra-high M(w) PHB in a methane-utilizing mixed culture can be induced by potassium deficiency. This study greatly extends the knowledge in the field of bacterial biopolymer formation with gaseous substrates. The special system used here combines the use of methane a low-cost substrate available from natural and renewable sources with the possibility of employing a mixed-culture in an open system for the synthesis of a high-value product.Keywords
This publication has 54 references indexed in Scilit:
- High level production of supra molecular weight poly (3-hydroxybutyrate) by metabolically engineeredEscherichia coliBiotechnology and Bioprocess Engineering, 2004
- Mechanical properties and highly ordered structure of ultra-high-molecular-weight poly[(R)-3-hydroxybutyrate] films: Effects of annealing and two-step drawingPolymer Degradation and Stability, 2003
- The membrane-associated form of methane mono-oxygenase from Methylococcus capsulatus (Bath) is a copper/iron proteinBiochemical Journal, 2003
- Physiology, Regulation, and Limits of the Synthesis of Poly(3HB)Advances in Biochemical Engineering/Biotechnology, 2001
- Methylobacterium rhodesianum produces poly-3-hydroxybutyrate and after mutagenesis in addition exopolysaccharidesActa Biotechnologica, 1999
- High-cell-density production of poly-β-hydroxybutyrate (PHB) from methanol by Methylobacterium extorquens: production of high-molecular-mass PHBApplied Microbiology and Biotechnology, 1995
- Effect of single nutrient limitation of poly‐β‐hydroxybutyrate molecular weight distribution in alcaligens europhusBiotechnology & Bioengineering, 1995
- The effect of substrate on the molecular weight ofpoly-?-hydroxybutyrate produced byAzotobacter vinelandii UWDBiotechnology Letters, 1994
- Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates.Microbiological Reviews, 1990
- Microbial Conversion of Methane into poly-β-hydroxybutyrate (PHB): Growth and intracellular product accumulation in a type II methanotrophJournal of Fermentation Technology, 1986