Polycyclic Aromatic Hydrocarbon Degradation of Phytoplankton-Associated Arenibacter spp. and Description of Arenibacter algicola sp. nov., an Aromatic Hydrocarbon-Degrading Bacterium

Abstract

g Pyrosequencing of the bacterial community associated with a cosmopolitan marine diatom during enrichment with crude oil revealed several Arenibacter phylotypes, of which one (OTU-202) had become significantly enriched by the oil. Since members of the genus Arenibacter have not been previously shown to degrade hydrocarbons, we attempted to isolate a representative strain of this genus in order to directly investigate its hydrocarbon-degrading potential. Based on 16S rRNA sequencing, one isolate (designated strain TG409 T ) exhibited >99% sequence identity to three type strains of this genus. On the basis of phenotypic and genotypic characteristics, strain TG409T represents a novel species in the genus Arenibacter, for which the name Arenibacter algicola sp. nov. is proposed. We reveal for the first time that polycyclic aromatic hydrocarbon (PAH) degradation is a shared phenotype among members of this genus, indicating that it could be used as a taxonomic marker for this genus. Kinetic data for PAH mineralization rates showed that naphthalene was preferred to phenanthrene, and its mineralization was significantly enhanced in the presence of glass wool (a surrogate for diatom cell surfaces). During enrichment on hydrocarbons, strain TG409 T emulsified n-tetradecane and crude oil, and cells were found to be preferentially attached to oil droplets, indicating an ability by the strain to express cell surface amphiphilic substances (biosurfactants or bioemulsifiers) as a possible strategy to increase the bioavailability of hydrocarbons. This work adds to our growing knowledge on the diversity of bacterial genera in the ocean contributing to the degradation of oil contaminants and of hydrocarbondegrading bacteria found living in association with marine eukaryotic phytoplankton.

Unexpected Diversity and High Abundance of Putative Nitric Oxide Dismutase (Nod) Genes in Contaminated Aquifers and Wastewater Treatment Systems

“…5). Even more surprisingly, the Nor-related gene of Arenibacter algicola, an aerobic degrader of polycyclic aromatic hydrocarbons (31), retained all the residual substitutions characteristic of Nod (Fig. 5).…”

Response of the bacterial community associated with a cosmopolitan marine diatom to crude oil shows a preference for the biodegradation of aromatic hydrocarbons

“…Emerging evidence over the past decade has revealed the occurrence of eukaryotic phytoplankton as a potentially important biotope for finding hydrocarbon‐degrading bacteria (Green et al ., ; Gutierrez and Aitken, ; Gutierrez et al ., ), including obligate hydrocarbonoclastic bacteria (Gutierrez et al ., 2012a,b; 2013). The ecology and life cycle of these types of bacteria in the ocean, respective to their possible interactions with and close dependence on other organisms, is an area that is in a nascent phase of understanding.…”

Biosurfactant activity, heavy metal tolerance and characterization of Joostella strain A8 from the Mediterranean polychaete Megalomma claparedei (Gravier, 1906)

“…To the best of our knowledge, among marine Flavobacteriaceae biosurfactant compounds have been rarely isolated from strains grown on hydrocarbons, e.g. Myroides pelagicus (Maneerat et al 2006) and Arenibacter algicola (Gutierrez et al 2014), and we only recently reported about biosurfactant production by Joostella isolates (Rizzo et al 2013(Rizzo et al , 2014. Several parameters such as carbon source, concentration of ions, temperature and pH could influence the biosurfactant production (i.e.…”