Stenotrophomonas sp. Pemsol isolated from crude oil contaminated soil in Mexico that can degrade polycyclic aromatic hydrocarbons and its whole genome sequence analyzed

Background: Stenotrophomonas are ubiquitous gram-negative bacteria which survive in a wide range of environments. They can use many substances for their growth and are known to be intrinsically resistant to many antimicrobial agents. They have been tested for biotechnological applications, bioremediation and antimicrobial agents because of their recalcitrant nature to many toxic compounds. Method. Stenotrophomonas sp. Pemsol was isolated from a crude oil contaminated soil. The capability of this isolate to tolerate and degrade polycyclic aromatic hydrocarbons (PAHs) (anthracene, anthraquinone, biphenyl, naphthalene, phenanthrene, phenanthridine and xylene) was evaluated on Bush Nell Hass medium containing PAHs as the unique carbon sources. The metabolites formed after 30-day degradation of naphthalene by Pemsol were analyzed using Fourier Transform Infra-red Spectroscopic (FTIR), Ultra-Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS) and Gas Chromatography-Mass Spectrometry (GC-MS). Results. Complete degradation of naphthalene at a concentration of 1 mg/mL was obtained and a newly formed catechol peak obtained from the UPLC-MS and GC-MS confirmed the degradation. The strain Pemsol lacked the ability to produce biosurfactant so that it cannot bio-emulsify PAHs. The whole genome analysis of Stenotrophomonas sp. Pemsol revealed a wealth of genes for hydrocarbon utilization and interaction with the environment and the presence of 147 genes associated with the degradation of PAHs, some of which are strain-specific on the genomic islands. Few genes are associated with bio-emulsification indicated that Pemsol without biosurfactant production has a genetic basis. This is the first report of the complete genome analysis sequence of a PAH-degrading Stenotrophomonas. Stenotrophomonas sp. Pemsol possesses features that makes it a good bacterium for genetic engineering and will therefore be a good tool for the remediation of crude oil or PAH-contaminated soil.

Download Full-text

The Polycyclic Aromatic Hydrocarbon (PAH) degradation activities and genome analysis of a novel strain Stenotrophomonas sp. Pemsol isolated from Mexico

PeerJ ◽

10.7717/peerj.8102 ◽

2020 ◽

Vol 8 ◽

pp. e8102

Author(s):

Temidayo O. Elufisan ◽

Isabel C. Rodríguez-Luna ◽

Omotayo Opemipo Oyedara ◽

Alejandro Sánchez-Varela ◽

Armando Hernández-Mendoza ◽

...

Keyword(s):

Mass Spectrometry ◽

Crude Oil ◽

Contaminated Soil ◽

Antimicrobial Agents ◽

Carbon Sources ◽

Genomic Islands ◽

Gas Chromatography Mass Spectrometry ◽

Chromatography Mass Spectrometry ◽

Wide Range ◽

Polycyclic Aromatic

Background Stenotrophomonas are ubiquitous gram-negative bacteria, which can survive in a wide range of environments. They can use many substances for their growth and are known to be intrinsically resistant to many antimicrobial agents. They have been tested for biotechnological applications, bioremediation, and production of antimicrobial agents. Method Stenotrophomonas sp. Pemsol was isolated from a crude oil contaminated soil. The capability of this isolate to tolerate and degrade polycyclic aromatic hydrocarbons (PAH) such as anthraquinone, biphenyl, naphthalene, phenanthrene, phenanthridine, and xylene was evaluated in Bushnell Hass medium containing PAHs as the sole carbon sources. The metabolites formed after 30-day degradation of naphthalene by Pemsol were analyzed using Fourier Transform Infra-red Spectroscopic (FTIR), Ultra-Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS) and Gas Chromatography-Mass Spectrometry (GC-MS). The genome of Pemsol was also sequenced and analyzed. Results Anthraquinone, biphenyl, naphthalene, phenanthrene, and phenanthridine except xylene can be used as sole carbon sources for Pemsol’s growth in Bushnell Hass medium. The degradation of naphthalene at a concentration of 1 mg/mL within 30 days was tested. A newly formed catechol peak and the disappearance of naphthalene peak detected on the UPLC-MS, and GC-MS analyses spectra respectively confirmed the complete degradation of naphthalene. Pemsol does not produce biosurfactant and neither bio-emulsify PAHs. The whole genome was sequenced and assembled into one scaffold with a length of 4,373,402 bp. A total of 145 genes involved in the degradation of PAHs were found in its genome, some of which are Pemsol-specific as compared with other 11 Stenotrophomonas genomes. Most specific genes are located on the genomic islands. Stenotrophomonas sp. Pemsol’s possession of few genes that are associated with bio-emulsification gives the genetic basis for its inability to bio-emulsify PAH. A possible degradation pathway for naphthalene in Pemsol was proposed following the analysis of Pemsol’s genome. ANI and GGDH analysis indicated that Pemsol is likely a new species of Stenotrophomonas. It is the first report on a complete genome sequence analysis of a PAH-degrading Stenotrophomonas. Stenotrophomonas sp. Pemsol possesses features that make it a good bacterium for genetic engineering and will be an excellent tool for the remediation of crude oil or PAH-contaminated soil.

Download Full-text