Metabolic pathway for a new strain Pseudomonas synxantha LSH-7': from chemotaxis to uptake of n-hexadecane

Sci Rep. 2017 Jan 4:7:39068. doi: 10.1038/srep39068.

Abstract

Bacteria can use n-hexadecane as a carbon source, but it remains incompletely understood whether n-hexadecane is transformed into metabolic intermediates prior to cellular uptake or not. We newly isolated a strain identified as Pseudomonas synxantha LSH-7' and conducted chemotaxis experiment of this bacterial strain towards n-hexadecane, hexadecanol and hexadecanoic acid with qualitative assays respectively. Furthermore, we described the identification of extracellular alkane hydroxylase and alcohol dehydrogenase activity; acidification of the culture medium; identification of hexadecanoic acid in the culture medium by the GC-MS analysis; and variation concentration of intracellular n-hexadecane and hexadecanoic acid. A detailed analysis of the experimental data revealed the chemotaxis of this bacterial strain towards n-hexadecane instead of its metabolic intermediates. Our results further suggested that only a fraction of total n-hexadecane followed this path, and alkane hydrolase and hexadecanol dehydrogenase were constitutively expressed when grown in the medium of n-hexadecane. Most strikingly, we quantitatively investigated the concentration of n-hexadecane adsorbed by bacterial chemotaxis. Our findings provided an original insight n-hexadecane might be converted to hexadecanoic acid extracellularly before it was taken up across the cell membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Dehydrogenase / analysis
  • Alkanes / metabolism*
  • Biological Transport
  • Carbon / metabolism
  • Chemotaxis*
  • Culture Media / chemistry
  • Cytochrome P-450 CYP4A / analysis
  • Gas Chromatography-Mass Spectrometry
  • Hydrogen-Ion Concentration
  • Metabolic Networks and Pathways*
  • Palmitic Acid / metabolism
  • Pseudomonas / enzymology
  • Pseudomonas / genetics*
  • Pseudomonas / isolation & purification
  • Pseudomonas / physiology*

Substances

  • Alkanes
  • Culture Media
  • Palmitic Acid
  • Carbon
  • Alcohol Dehydrogenase
  • Cytochrome P-450 CYP4A
  • n-hexadecane