Subsurface Associations of Acaryochloris-Related Picocyanobacteria with Oil-Utilizing Bacteria in the Arabian Gulf Water Body: Promising Consortia in Oil Sediment Bioremediation

Abstract

Two picocyanobacterial strains related to Acaryochloris were isolated from the Arabian Gulf, 3 m below the water surface, one from the north shore and the other from the south shore of Kuwait. Both strains were morphologically, ultrastructurally, and albeit to a less extend, phylogenetically similar to Acaryochloris. However, both isolates lacked chlorophyll d and produced instead chlorophyll a, as the major photosynthetic pigment. Both picocyanobacterial isolates were associated with oil-utilizing bacteria in the magnitude of 10(5) cells g(-1). According to their 16S rRNA gene sequences, bacteria associated with the isolate from the north were affiliated to Paenibacillus sp., Bacillus pumilus, and Marinobacter aquaeolei, but those associated with the isolate from the south were affiliated to Bacillus asahii and Alcanivorax jadensis. These bacterial differences were probably due to environmental variations. In batch cultures, the bacterial consortia in the nonaxenic biomass as well as the pure bacterial isolates effectively consumed crude oil and pure aliphatic and aromatic hydrocarbons, including very high-molecular-weight compounds. Water and diethylether extracts from the phototrophic biomass enhanced growth of individual bacterial isolates and their hydrocarbon-consumption potential in batch cultures. It was concluded that these consortia could be promising in bioremediation of hydrocarbon pollutants, especially heavy sediments in the marine ecosystem.

Rapid TaqMan-Based Quantification of Chlorophyll d -Containing Cyanobacteria in the Genus Acaryochloris

“…As no weight normalization was done in the latter studies, we can only hypothesize about exact numbers of cells being present. However, a recent study found ϳ10 5 cells g Ϫ1 Acaryochloris species in (subtropical) oil-associated communities (corresponding to 10 3 cells mg Ϫ1 ) (35). Such a cell density resembles our concentration estimates in CCAs from the Red Sea and Australia (8.90 ϫ 10 2 to 1.51 ϫ 10 3 ).…”

“…Still, not all findings of Acaryochloris species are necessarily linked to the cooccurrence of Chl d. An Acaryochloris sp. strain was, e.g., recently obtained from oil-utilizing communities and reported to not contain Chl d (35). Also, other Acaryochloris strains have been reported, such as Acaryochloris sp.…”

Crude oil pollution and biodegradation at the Persian Gulf: A comprehensive and review study

“…Their 16S rRNA gene sequences indicated that related bacteria isolated from the north were associated with Paenibacillus sp., Bacillus pumilus, and Marinobacter aquaeolei, but those related that isolated from the south were associated to Bacillus asahii and Alcanivorax jadensis. These bacterial diversities occur presumably because of environmental variations [92].…”

Bacterial Degradation of the Saturate Fraction of Arabian Light Crude oil: Biosurfactant Production and the Effect of ZnO Nanoparticles

“…Although more than two decades have elapsed since the catastrophic Gulf war oil spill occurred, the consequences are still apparent today [10]. Following the 1991 Gulf war, some studies have been conducted to evaluate bioremediation as a cleanup technology in the Arabian Gulf territory [9,12,13]. Nonetheless, the work achieved to date is not up to the scale of the massive pollution problem.…”