Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela 769 008, Odisha, India.
Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela 769 008, Odisha, India.
J Hazard Mater. 2023 Sep 5;457:131795. doi: 10.1016/j.jhazmat.2023.131795. Epub 2023 Jun 7.
Biofilm-forming marine bacterium Pseudomonas furukawaii PPS-19 showed strong hydrophobicity under different physicochemical stressors, such as pH and salinity. Strong aggregation of P. furukawaii PPS-19 was observed at hydrophobic interfaces of n-dodecane and crude oil, while uptake of pyrene resulted in blue fluorescence of the bacterium. Changes in biofilm microcolonies were observed under different physicochemical stressors with maximum biofilm thickness of 15.15 µm and 15.77 µm at pH 7% and 1% salinity, respectively. Relative expression analysis of alkB2 gene revealed the maximum expression in n-dodecane (10.5 fold) at pH 7 (1 fold) and 1% salinity (8.3 fold). During the degradation process, a significant drop in surface tension resulted in increased emulsification activity. P. furukawaii PPS-19 showed the respective n-dodecane and pyrene degradation of 94.3% and 81.5% at pH 7% and 94.5% and 83% at 1% salinity. A significant positive correlation was obtained between cell surface hydrophobicity (CSH), biofilm formation, and PHs degradation (P < 0.05) under all the physicochemical stressors, with the highest value at pH 7% and 1% salinity. Analysis of metabolites indicated that mono-terminal oxidation and multiple pathways were followed for n-dodecane and pyrene biodegradation, respectively. Thus, P. furukawaii PPS-19 is an efficient hydrocarbonoclastic bacterium that may be exploited for large-scale oil pollution abatement.
具有生物膜形成能力的海洋细菌假单胞菌 PPS-19 在不同的物理化学胁迫下，如 pH 值和盐度，表现出很强的疏水性。在正十二烷和原油的疏水平面上，观察到假单胞菌 PPS-19 的强烈聚集，而芘的摄取导致细菌发出蓝色荧光。在不同的物理化学胁迫下，观察到生物膜微菌落的变化，在 pH 值为 7%和盐度为 1%时，生物膜的最大厚度分别为 15.15 μm 和 15.77 μm。alkB2 基因的相对表达分析显示，在 pH 值为 7（1 倍）和盐度为 1%（8.3 倍）的正十二烷中表达最高（10.5 倍）。在降解过程中，表面张力的显著下降导致乳化活性增加。在 pH 值为 7%和盐度为 94.5%时，假单胞菌 PPS-19 对正十二烷和芘的降解率分别为 94.3%和 81.5%，在 pH 值为 1%和盐度为 83%时，降解率分别为 94.5%和 83%。在所有物理化学胁迫下，细胞表面疏水性（CSH）、生物膜形成和 PHs 降解之间都获得了显著的正相关（P<0.05），在 pH 值为 7%和盐度为 1%时达到最高值。代谢物分析表明，正十二烷和芘的生物降解分别遵循单端氧化和多种途径。因此，假单胞菌 PPS-19 是一种高效的烃类降解细菌，可用于大规模的石油污染治理。
