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Isolation of a thermotolerant bacterium producing mediumâchainâlength polyhydroxyalkanoate
- Satoh, Y., Tajima, K., Nakamoto, S., Xuerong, H., Matsushima, T., Ohshima, T., Kawano, S., Erata, T., Dairi, T., Munekata, M.
- Journal of applied microbiology 2011 v.111 no.4 pp. 811-817
- Pseudomonas, acetates, bacteria, biodiesel, carbon, heat tolerance, industry, microbial growth, nucleotide sequences, phylogeny, polyhydroxyalkanoates, production costs, ribosomal RNA, sequence analysis, temperature
- Aims: The aim of this study was to isolate a thermotolerant microâorganism that produces polyhydroxyalkanoates (PHAs) composed of mediumâchainâlength (mcl) HA units from a biodiesel fuel (BDF) byâproduct as a carbon source. Methods and Results: We successfully isolated a thermotolerant microâorganism, strain SG4502, capable to accumulate mclâPHA from a BDF byâproduct as a carbon source at a cultivation temperature of 45Â°C. The strain could also produce mclâPHA from acetate, octanoate and dodecanoate as sole carbon sources at cultivation temperatures up to 55Â°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. Conclusions: A novel thermotolerant bacterium capable to accumulate mclâPHA from a BDF byâproduct was successfully isolated. Significance and Impact of the Study: A major issue regarding industrial production of microbial PHAs is their much higher production cost compared with conventional petrochemicalâbased 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 byâproduct and produces PHA at high temperature, would be very useful for practical application in industry.