Effects of temperature and fertilization on total vs. active bacterial communities exposed to crude and diesel oil pollution in NW Mediterranean Sea.

The dynamics of total and active microbial communities were studied in seawater microcosms amended with crude or diesel oil at different temperatures (25, 10 and 4 degrees C) in the presence/absence of organic fertilization (Inipol EAP 22). Total and hydrocarbon-degrading microbes were enumerated by fluorescence microscopy and Most Probable Number (MPN) method, respectively. Total (16S rDNA-based) vs.

Gallaecimonas pentaromativorans gen. nov., sp. nov., a bacterium carrying 16S rRNA gene heterogeneity and able to degrade high-molecular-mass polycyclic aromatic hydrocarbons.

A Gram-negative, rod-shaped, halotolerant bacterium, designated strain CEE_131(T), which degraded high-molecular-mass polycyclic aromatic hydrocarbons of four and five rings, was isolated from intertidal sediment of Corcubion Ria in Cee, A Coruña, Spain. Direct sequencing showed ambiguities and suggested heterogeneity. Cloned 16S rRNA gene sequence PCR products yielded five different sequences varying at five positions.

Comparative mesocosm study of biostimulation efficiency in two different oil-amended sub-antarctic soils.

Biological treatment has become increasingly popular as a remediation method for soils and groundwater contaminated with petroleum hydrocarbon, chlorinated solvents, and pesticides. Bioremediation has been considered for application in cold regions such as Arctic and sub-Arctic climates and Antarctica. Studies to date suggest that indigenous microbes suitable for bioremediation exist in soils in these regions.

Predominance of Roseobacter, Sulfitobacter, Glaciecola and Psychrobacter in seawater collected off Ushuaia, Argentina, Sub-Antarctica.

Bacterial diversity in sub-Antarctic seawater, collected off Ushuaia, Argentina, was examined using a culture independent approach. The composition of the 16S rRNA gene libraries from seawater and seawater contaminated with the water soluble fraction of crude oil was statistically different (P value 0.001).

Marinomonas polaris sp. nov., a psychrohalotolerant strain isolated from coastal sea water off the subantarctic Kerguelen islands.

Two aerobic, psychrohalotolerant, motile bacterial isolates, CK13T and CK16, isolated from sea-water samples collected off the subantarctic Kerguelen island, were characterized by using a polyphasic taxonomic approach. On the basis of 16S rRNA gene sequence data, the strains were 99.6% similar and exhibited 93-97% similarity with the seven recognized species of Marinomonas.

Marinobacter maritimus sp. nov., a psychrotolerant strain isolated from sea water off the subantarctic Kerguelen islands.

A psychrotolerant, Gram-negative, motile bacterium, designated CK 47(T), was isolated from sea water off the subantarctic Kerguelen islands (50 degrees 40' S 68 degrees 25' E). The isolate grew optimally at 22 degrees C and minimum and maximum temperature of growth were 4 and 37 degrees C, respectively. It required Na(+) for growth and exhibited optimum growth at pH 8.

Effects of nutrient and temperature on degradation of petroleum hydrocarbons in contaminated sub-Antarctic soil.

Mesocosm studies using sub-Antarctic soil artificially contaminated with diesel or crude oil were conducted in Kerguelen Archipelago (49 degrees 21' S, 70 degrees 13' E) in an attempt to evaluate the potential of a bioremediation approach in high latitude environments. All mesocosms were sampled on a regular basis over six months period. Soils responded positively to temperature increase from 4 degrees C to 20 degrees C, and to the addition of a commercial oleophilic fertilizer containing N and P.

Marinomonas ushuaiensis sp. nov., isolated from coastal sea water in Ushuaia, Argentina, sub-Antarctica.

A Gram-negative, rod-shaped, psychrophilic, motile, non-spore-forming bacterium, strain U1T, was isolated from Ushuaia located at the southernmost tip of Argentina. On the basis of 16S rRNA gene sequence similarity, strain U1T was found to be closely related to Marinomonas communis (DSM 5604T) and Marinomonas primoryensis (IAM 15010T). At the DNA-DNA level, however, the values for similarity were 41 and 25 %, respectively.

Psychrobacter salsus sp. nov. and Psychrobacter adeliensis sp. nov. isolated from fast ice from Adelie Land, Antarctica.

Nine psychrotolerant bacteria were isolated from fast ice in the middle of Geologie Archipelago, Adelie Land, Antarctica and were categorized into two groups, based on their SDS-PAGE profiles. Representatives from each of the two groups, namely strains DD 48T and SJ 14T exhibited phenotypic and chemotaxonomic characteristics confirming to the genus Psychrobacter. The 16S rRNA gene sequence indicated that the two isolates are closely related to each other and to the already reported fifteen species of Psychrobacter.

Degradation of petroleum hydrocarbons in two sub-antarctic soils: influence of an oleophilic fertilizer.

In order to determine the long-term effects of fertilizer on the degradation rate and the toxicity of hydrocarbons in sub-Antarctic soils contaminated by petroleum hydrocarbons, a field study was initiated in December 2000 on two different soils of the Kerguelen Islands (69 degrees 42'E, 49 degrees 19'S). The number of hydrocarbon-degrading bacteria (HDB) increased greatly after crude-oil and diesel-fuel contamination, and the fertilizer addition had a favorable effect on HDB growth and activity. Hydrocarbon-degrading bacteria counts remained high until the end of the experiment although the total hydrocarbon content in all contaminated soils was reduced to 80 to 90% of their initial value after 330 d.

Halomonas glaciei sp. nov. isolated from fast ice of Adelie Land, Antarctica.

Eleven psychrophilic bacteria were isolated from a solid layer of fast ice in the middle of Pointe-Geologie Archipelago, Adelie Land, Antarctica. The 11 isolates based on the phenotypic characteristics, chemotaxonomic and phylogenetic analysis have been identified as members of the genus Halomonas. All the isolates at the 16S rDNA sequence level were identical, possessed the 15 conserved nucleotides of the family Halomonadaceae and four nucleotides of the genus Halomonas.