Characterization of Five Psychrotolerant Alcanivorax spp. Strains Isolated from Antarctica

Abstract

Five psychrotolerant Alcanivorax spp. strains were isolated from Antarctic coastal waters. Strains were screened for molecular and physiological properties and analyzed regarding their growth capacity. Partial 16S rDNA, alk-B1, and P450 gene sequencing was performed. Biolog EcoPlates and the API 20E test were used to evaluate metabolic and biochemical profiles. Bacterial growth in sodium acetate was determined at 4, 15, 20, and 25 °C to evaluate the optimal temperature. Furthermore, the ability of each strain to grow in a hydrocarbon mixture at 4 and 25 °C was assayed. Biosurfactant production tests (drop-collapse and oil spreading) and emulsification activity tests (E24) were also performed. Concerning results of partial gene sequencing (16S rDNA, alk-B1, and P450), a high similarity of the isolates with the same genes isolated from other Alcanivorax spp. strains was observed. The metabolic profiles obtained by Biolog assays showed no significant differences in the isolates compared to the Alcanivorax borkumensis wild type. The results of biodegradative tests showed their capability to grow at different temperatures. All strains showed biosurfactant production and emulsification activity. Our findings underline the importance to proceed in the isolation and characterization of Antarctic hydrocarbon-degrading bacterial strains since their biotechnological and environmental applications could be useful even for pollution remediation in polar areas.

Isolation of Symbiotic bacteria from Sponge Raspaciona aculeata

“…Genomic DNA was extracted from each isolated bacterial strain using the DNeasy Blood & Tissue Kit (50), QIAGEN, Germany, following the procedures described by the manufacturer. PCR was carried out as previously described 2 .…”

Alcanivorax borkumensis and Bioremediation: The Actual Perspective of a Vintage Bacteria

“…At the same time, the presence of A. borkumensis associated with marine invertebrates seems to reflect a special ecological niche containing readily accessible hydrocarbons produced by the animal partners. Interestingly, although bacteria and Alcanivorax-related 16S rRNA gene sequences has been retrieved from microbial communities inhabiting cold polar areas, the organism itself has so far only been isolated from more temperate lower latitudes [2,4,5]. Normally, this bacterium is found in low numbers in unpolluted environments, but it quickly becomes the dominant microbe in oil-polluted open ocean and coastal waters, where it may comprise up to 80-90% of the oil-degrading microbial community [6][7][8].…”