Mechanism of A. oleivorans S4 treating soluble phosphorus deficiency and hydrocarbon contamination simultaneously

• Published in: The Science of the total environment 2024-11, Vol.949, p.175215, Article 175215
• Main Authors: Wang, Panpan, Chen, Chaoqi, Liao, Kejun, Tao, Yue, Fu, Yaojia, Chen, Lanzhou
• Format: Article
• Language: English
• Subjects: A. oleivorans S4; Acinetobacter; bacteria; biomass; bioremediation; carbon; energy; environment; gluconates; glucose; hexadecane; Incomplete glucose metabolism; metabolism; oxidative stress; petroleum; Petroleum hydrocarbons degradation; Phosphate solubilization; soil; soluble phosphorus; starvation; transcriptomics; trehalose; tricalcium phosphate; tricarboxylic acid cycle
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.175215

Both soluble phosphorus (P) deficiency and petroleum hydrocarbon contamination represent challenges in soil environments. While phosphate-solubilizing bacteria and hydrocarbon-degrading bacteria have been identified and employed in environmental bioremediation, the bacteria co-adapted to soluble P deficiency and hydrocarbon contamination has rarely been reported. This study explored the ability of Acinetobacter oleivorans S4 (A. oleivorans S4) to solubilize phosphate using n-hexadecane (H), glucose (G), and a mixed carbon source (HG) in tricalcium phosphate (TCP) medium. A. oleivorans S4 exhibited robust growth in H-TCP, releasing 31 mg L−1 of soluble P. Conversely, A. oleivorans S4 barely grew in G-TCP, releasing 654 mg L−1 of soluble P. In HG-TCP, biomass surpassed that in H-TCP, with phosphate release comparable to that in G-TCP. HPLC analysis revealed a small amount of TCA cycle acids in H-TCP and a large amount of gluconate in G-TCP and HG-TCP. Transcriptomic analysis showed elevated expression of genes associated with alkane degradation, P starvation, N utilization, and trehalose synthesis in H-TCP, revealing the molecular co-adaptation mechanism of A. oleivorans S4. Furthermore, the addition of glucose enhanced alkane degradation, P and N utilization, and reduced trehalose synthesis. It indicated that incomplete glucose metabolism may provide energy for other reactions, and the increase in soluble P mediated by gluconate may alleviate oxidative stress. Overall, A. oleivorans S4 proves promising for remediating soluble P-deficient and hydrocarbon-contaminated environments, and glucose stimulates its transformation into a super phosphate-solubilizing bacterium. [Display omitted] •A. oleivorans S4 is a candidate for remediating hydrocarbon-contaminated and P-deficient environment.•A. oleivorans S4 can utilize n-hexadecane in the absence of soluble P.•The incomplete glucose metabolism results in the release of >600 mg L−1 soluble P.•Glucose enhances n-hexadecane metabolism and P utilization by A. oleivorans S4.