title: Thermophilic production of polyhydroxyalkanoates by a novel Aneurinibacillus strain isolated from Gudao oilfield, China.
abstract: Polyhydroxyalkanoates (PHAs) are usually biosynthesized using mesophilic strains, but the fermentation processes often suffer from bacterial contamination. This work reports the screening of thermophilic bacteria capable of producing PHAs under elevated temperatures to reduce the contamination risk. Strain XH2 was isolated from an oilfield and identified as Aneurinibacillus sp. by morphology, physiological-biochemical characterization, and 16S rDNA phylogenetic analysis. This strain can produce PHA granules, which was detected by Nile red staining and transmission electron microscopic imaging. At 55 °C, 111.6 mg l(-1) of PHA was produced in a fermentation medium containing glucose, peptone, and yeast extract. If peptone was removed from the medium, the yield of PHA would be enhanced by 2.4 times. The main monomers of the PHA product were identified to be 3-hydroxybutyrate and 3-hydroxyvalerate with a molar ratio of 17.2:1 by gas chromatography-mass spectroscopy (GC-MS) and nuclear magnetic resonance analyses. Two minor homologues, 3-hydroxyoctanoate, and 3-hydroxy-4-phenylbutanoate, were tentatively identified by GC-MS as well. This is the first report of thermophilic PHA bacterial producer from the Firmicutes phylum.
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering & Biotechnology, China University of Petroleum, Qingdao, China.
authors.forename: Zijun
authors.initials: Z
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering & Biotechnology, China University of Petroleum, Qingdao, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering & Biotechnology, China University of Petroleum, Qingdao, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Xi
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering & Biotechnology, China University of Petroleum, Qingdao, China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Huo
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering & Biotechnology, China University of Petroleum, Qingdao, China.
authors.forename: Jing-yi
authors.initials: JY
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Heavy Oil Processing and Center for Bioengineering & Biotechnology, China University of Petroleum, Qingdao, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
mesh_terms: D002681:China; D002849:Chromatography, Gas; D005285:Fermentation; D013058:Mass Spectrometry; D008854:Microscopy, Electron; D061329:Oil and Gas Fields / Q000737:chemistry / Q000382:microbiology*; D056507:Paenibacillus / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D010802:Phylogeny; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis* / Q000737:chemistry
chemical_list: D054813:Polyhydroxyalkanoates
keywords: 3-Hydroxybutyrate; 3-Hydroxyvalerate; Aneurinibacillus; Polyhydroxyalkanoates; Thermophilic bacterium