alexa Physiological adaptations involved in alkane assimilation at a low temperature by Rhodococcus sp. strain Q15.
Environmental Sciences

Environmental Sciences

Journal of Bioremediation & Biodegradation

Author(s): Whyte LG, Slagman SJ, Pietrantonio F, Bourbonnire L, Koval SF,

Abstract Share this page

Abstract We examined physiological adaptations which allow the psychrotroph Rhodococcus sp. strain Q15 to assimilate alkanes at a low temperature (alkanes are contaminants which are generally insoluble and/or solid at low temperatures). During growth at 5 degrees C on hexadecane or diesel fuel, strain Q15 produced a cell surface-associated biosurfactant(s) and, compared to glucose-acetate-grown cells, exhibited increased cell surface hydrophobicity. A transmission electron microscopy examination of strain Q15 grown at 5 degrees C revealed the presence of intracellular electron-transparent inclusions and flocs of cells connected by an extracellular polymeric substance (EPS) when cells were grown on a hydrocarbon and morphological differences between the EPS of glucose-acetate-grown and diesel fuel-grown cells. A lectin binding analysis performed by using confocal scanning laser microscopy (CSLM) showed that the EPS contained a complex mixture of glycoconjugates, depending on both the growth temperature and the carbon source. Two glycoconjugates [beta-D-Gal-(1-3)-D-GlcNAc and alpha-L-fucose] were detected only on the surfaces of cells grown on diesel fuel at 5 degrees C. Using scanning electron microscopy, we observed strain Q15 cells on the surfaces of octacosane crystals, and using CSLM, we observed strain Q15 cells covering the surfaces of diesel fuel microdroplets; these findings indicate that this organism assimilates both solid and liquid alkane substrates at a low temperature by adhering to the alkane phase. Membrane fatty acid analysis demonstrated that strain Q15 adapted to growth at a low temperature by decreasing the degree of saturation of membrane lipid fatty acids, but it did so to a lesser extent when it was grown on hydrocarbons at 5 degrees C; these findings suggest that strain Q15 modulates membrane fluidity in response to the counteracting influences of low temperature and hydrocarbon toxicity.
This article was published in Appl Environ Microbiol and referenced in Journal of Bioremediation & Biodegradation

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • 6th World Congress on Biofuels and Bioenergy
    Sep 5-6, 2017 London, UK
  • 6th World Congress on Biopolymers
    September 7-9, 2017 Paris, France
  • 7th International Conference and Exhibition on Biopolymers and Bioplastics
    October 19-21, 2017 San Francisco, USA
Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version