Division of Biotechnology and Macromolecular Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo, Japan.
J Appl Microbiol. 2011 Oct;111(4):811-7. doi: 10.1111/j.1365-2672.2011.05093.x. Epub 2011 Jul 20.
The aim of this study was to isolate a thermotolerant micro-organism that produces polyhydroxyalkanoates (PHAs) composed of medium-chain-length (mcl) HA units from a biodiesel fuel (BDF) by-product as a carbon source.
We successfully isolated a thermotolerant micro-organism, strain SG4502, capable to accumulate mcl-PHA from a BDF by-product as a carbon source at a cultivation temperature of 45°C. The strain could also produce mcl-PHA from acetate, octanoate and dodecanoate as sole carbon sources at cultivation temperatures up to 55°C. Taxonomic studies and 16S rRNA gene sequence analysis revealed that strain SG4502 was phylogenetically affiliated with species of the genus Pseudomonas. This study is the first report of PHA synthesis by a thermotolerant Pseudomonas.
A novel thermotolerant bacterium capable to accumulate mcl-PHA from a BDF by-product was successfully isolated.
A major issue regarding industrial production of microbial PHAs is their much higher production cost compared with conventional petrochemical-based plastic materials. Especially significant are the cost of a fermentative substrate and the running cost to maintain a temperature suitable for microbial growth. Thus, strain SG4502, isolated in this study, which assimilates BDF by-product and produces PHA at high temperature, would be very useful for practical application in industry.
本研究旨在从生物柴油燃料（BDF）副产物作为碳源中分离出一种产生聚羟基烷酸酯（PHA）的耐热微生物，该 PHA 由中链长（mcl）HA 单元组成。
我们成功地从 BDF 副产物中分离出一种耐热微生物菌株 SG4502，该菌株能够在 45°C 的培养温度下积累 mcl-PHA 作为碳源。该菌株还能够在培养温度高达 55°C 时从乙酸盐、辛酸和月桂酸作为唯一碳源生产 mcl-PHA。分类学研究和 16S rRNA 基因序列分析表明，菌株 SG4502与假单胞菌属的物种在系统发育上有关。本研究首次报道了耐热假单胞菌合成 PHA。
成功分离出一种能够从 BDF 副产物中积累 mcl-PHA 的新型耐热细菌。
与传统的基于石油化工的塑料材料相比，微生物 PHA 的工业生产成本高是一个主要问题。特别重要的是发酵底物的成本和维持适合微生物生长的温度的运行成本。因此，本研究中分离出的菌株 SG4502，它可以同化 BDF 副产物并在高温下生产 PHA，将非常有益于工业中的实际应用。
