Differential Protein Expression During Growth on Medium Versus Long-Chain Alkanes in the Obligate Marine Hydrocarbon-Degrading Bacterium Thalassolituus oleivorans MIL-1

Abstract

The marine obligate hydrocarbonoclastic bacterium Thalassolituus oleivorans MIL-1 metabolizes a broad range of aliphatic hydrocarbons almost exclusively as carbon and energy sources. We used LC-MS/MS shotgun proteomics to identify proteins involved in aerobic alkane degradation during growth on medium- (n-C14) or long-chain (n-C28) alkanes. During growth on n-C14, T. oleivorans expresses an alkane monooxygenase system involved in terminal oxidation including two alkane 1-monooxygenases, a ferredoxin, a ferredoxin reductase and an aldehyde dehydrogenase. In contrast, during growth on long-chain alkanes (n-C28), T. oleivorans may switch to a subterminal alkane oxidation pathway evidenced by significant upregulation of Baeyer-Villiger monooxygenase and an esterase, proteins catalyzing ketone and ester metabolism, respectively. The metabolite (primary alcohol) generated from terminal oxidation of an alkane was detected during growth on n-C14 but not on n-C28 also suggesting alternative metabolic pathways. Expression of both active and passive transport systems involved in uptake of long-chain alkanes was higher when compared to the non-hydrocarbon control, including a TonB-dependent receptor, a FadL homolog and a specialized porin. Also, an inner membrane transport protein involved in the export of an outer membrane protein was expressed. This study has demonstrated the substrate range of T. oleivorans is larger than previously reported with growth from n-C10 up to n-C32. It has also greatly enhanced our understanding of the fundamental physiology of T. oleivorans, a key bacterium that plays a significant role in natural attenuation of marine oil pollution, by identifying key enzymes expressed during the catabolism of n-alkanes.

Protein expression in the obligate hydrocarbon‐degrading psychrophile Oleispira antarctica RB‐8 during alkane degradation and cold tolerance

“…The origin of the hydrocarbon degradation genes from potentially more mesophilic hydrocarbon degraders, their versatile activity temperature range and the use of a cold‐adapted chaperonin system may explain why there was no significant difference in the growth rates at 4°C and 16°C. The growth rates calculated in this study were in a similar range to those for other OHCB growing on the same substrates, such as Alcanivorax borkumensis SK2 (Gregson et al ., ) and Thalassolituus oleivorans MIL‐1 (Gregson et al ., ).…”

“…MS/MS analysis was performed using the methods previously used in Gregson et al ., . Uniprot protein sequences from the O .…”

Bacterial Community Legacy Effects Following the Agia Zoni II Oil-Spill, Greece

“…Other alkane-degrading OHCB genera detected included Oleibacter ( Teramoto et al, 2011 ), Oleiphilus ( Golyshin et al, 2002 ), and Thalassolituus ( Yakimov et al, 2004b ; Gregson et al, 2018 ); though their abundance was primarily restricted to “Athens Oil 1” sediments. Oleibacter , Oleiphilus , and Thalassolituus have all been observed to increase in abundance in oil-contaminated marine environments, though until now evidence is lacking for detection in coastal sandy sediments (see Supplementary Table S2 ).…”

“…However, in April the relative abundance of both genera decreased to levels below 0.01%. Finally, OTU-972 assigned to Thalassolituus (Figures 4, 6), a genus containing species that can degrade a wide range of alkanes (Yakimov et al, 2004b;Gregson et al, 2018), was significantly more relatively abundant in sediments from contaminated sites in September (0.74%; coef. = 0.16, z = 7.52, p < 0.001) compared to uncontaminated control sediments.…”

Bioremediation of Diesel Contaminated Marine Water by Bacteria: A Review and Bibliometric Analysis

“…For n-alkanes (C 8 -C 40 ), the aerobic degradation is divided into three oxidation modes [124]. These modes are known as terminal oxidation [125], subterminal oxidation [126], and biterminal oxidation [127]. The oxidation modes take place at different carbon positions and form various end products.…”