Crude oil-induced structural shift of coastal bacterial communities of rod bay (Terra Nova Bay, Ross Sea, Antarctica) and characterization of cultured cold-adapted hydrocarbonoclastic bacteria

Abstract

For preliminary screening of human impact on Antarctic coasts, the compositions of microbial communities were analyzed in seawater at two sites located in the Terra Nova Bay of Antarctica (Ross Sea) by a combination of 16S rRNA gene sequencing and culture techniques. The bacterial community in the sample from the Rod Bay site, located at the proximity to the Italian Station, was characterized by a high abundance of 16S rRNA gene sequences belonging to the microflora typically found in soil and freshwater environments. In contrast, the seawater sample from the Adelie Cove station, a pristine reference site, contained 16S rRNA gene sequences typically found in marine areas affected by algal blooms and sea ice decay. The addition of crude oil to the Rod Bay seawater sample rapidly induced a shift in the composition of the bacterial community with appearance of novel taxonomic groups and a dramatic increase in the relative abundance of gamma-Proteobacteria sequences, whereas no significant changes were detected in the bacterial community of the Adelie Cove sample under the same conditions. Bacteria-exhibiting features with potential interest for industrial and environmental applications were isolated from the Rod Bay oil-enriched sample. In particular, hydrocarbon-degrading, cold-adapted bacteria were selectively enriched, isolated and screened for their ability to synthesize polyunsaturated fatty acids. Twenty two bacterial strains were isolated from the oil enrichment culture and identified. Eighteen isolates were found to be members of gamma-Proteobacteria, while the remainder were representatives of alpha-Proteobacteria, CFB and high G + C divisions.

The Variable Influence of Dispersant on Degradation of Oil Hydrocarbons in Subarctic Deep-Sea Sediments at Low Temperatures (0–5 °C)

“…The relative abundance of Pseudoalteromonas , which also became enriched in our model oil incubations, increased in the DWH deep water plume during partial capture as petroleum hydrocarbon concentrations decreased and the more dilute plume consisted of more BTEX relative to alkanes 20 . The decrease of ZD0117 in oil-enriched treatments in this study has also been observed in Antarctic seawater samples following contamination with oil 54 . The genus Colwellia is thought to play a predominant role hydrocarbon degradation in the deep sea.…”

Biosurfactant production by Arctic and Antarctic bacteria growing on hydrocarbons

“…The occurrence of Actinobacteria members in cold habitats has been often reported as being independent of contamination, as they are generally present to a similar degree in pristine and contaminated sites (Whyte et al 2002;Labbè et al 2007). Cold-adapted hydrocarbon-degrading members in this genus have been previously isolated from marine Antarctic areas, and their biodegradative potential has often been established (Yakimov et al 1999(Yakimov et al , 2004De Domenico et al 2004). According to the results of phylogenetic determination, it is possible to assume that only two Rhodococcus species were isolated.…”

Deep-Sea Oil Plume Enriches Indigenous Oil-Degrading Bacteria

“…The observed sequences in the plume samples form a clade with two distinct Oceanospirillales groups. One of these groups is largely composed of known psychrophilic hydrocarbon degraders and microorganisms from hydrocarbon-dominated environments (5,7,8), including Oleispira antarctica, Thalassolituus oleivorans, and Oleiphilus messinensis.…”