Effect of the bacterial community assembly process on the microbial remediation of petroleum hydrocarbon-contaminated soil

Abstract

IntroductionThe accumulation of petroleum hydrocarbons (PHs) in the soil can reduce soil porosity, hinder plant growth, and have a serious negative impact on soil ecology. Previously, we developed PH-degrading bacteria and discovered that the interaction between microorganisms may be more important in the degradation of PHs than the ability of exogenous-degrading bacteria. Nevertheless, the role of microbial ecological processes in the remediation process is frequently overlooked.MethodsThis study established six different surfactant-enhanced microbial remediation treatments on PH-contaminated soil using a pot experiment. After 30 days, the PHs removal rate was calculated; the bacterial community assembly process was also determined using the R language program, and the assembly process and the PHs removal rate were correlated.Results and discussionThe rhamnolipid-enhanced Bacillus methylotrophicus remediation achieved the highest PHs removal rate, and the bacterial community assembly process was impacted by deterministic factors, whereas the bacterial community assembly process in other treatments with low removal rates was affected by stochastic factors. When compared to the stochastic assembly process and the PHs removal rate, the deterministic assembly process and the PHs removal rate were found to have a significant positive correlation, indicating that the deterministic assembly process of bacterial communities may mediate the efficient removal of PHs. Therefore, this study recommends that when using microorganisms to remediate contaminated soil, care should be taken to avoid strong soil disturbance because directional regulation of bacterial ecological functions can also contribute to efficient removal of pollutants.

Lead toxicity in plants: mechanistic insights into toxicity, physiological responses of plants and mitigation strategies

“… 52 The leakage of petroleum hydrocarbon from refineries often introduces Pb into the soil, resulting in decreased soil porosity, microbial biomass and diversity, and microbial activity, which ultimately hinders plant growth. 53 Moreover, Pb contamination also affects soil enzymatic activity, with some enzymes being inhibited and others being activated, depending on the type of enzyme and the level of Pb contamination. 54 Overall, Pb contamination in soil may result in significant adverse impacts on soil microbial community and soil health, which can affect plant growth and ecosystem functioning.…”

“…Some of the investigations showed that rhamnolipid-enhanced Bacillus methylotrophicus exhibited the highest petroleum hydrocarbon removal rate from the leakage sites 53 whereas among plants Brassica pekinensis, Helianthus annuus , Vigna unguiculata , and Gomphrena globosa , were also found effective in eliminating Pb from soil. 184 In some of the investigations lime, gypsum, and phosphate were added to the soil to increase the pH resulting in a reduction in the the bioavailability of Pb to plants.…”

Degradation of DDT by a Novel Bacterium, Arthrobacter globiformis DC-1: Efficacy, Mechanism and Comparative Advantage

“…The new isolated bacterial strain, DC-1, was characterized and identified on the basis of its morphological and biochemical properties according to Bergey's manual of systematic bacteriology, combined with a 16S rDNA gene sequence analysis [25]. The morphological properties of the DC-1 cells were observed through light microscopy (OlymusDM-71, Kyoto, Japan).…”

Homogeneous environmental selection mainly determines the denitrifying bacterial community in intensive aquaculture water

“…It is generally accepted that both deterministic and stochastic processes simultaneously determine community assembly (Zhou and Ning, 2017;Ning et al, 2020). The degree of determinism in community assembly determines the predictability of the community and increases the potential for microbial community manipulation (Zheng et al, 2023a). Previous studies have shown that the assembly of denitrifying bacterial communities in bioreactors is primarily driven by stochastic processes , but more studies are needed to fully understand the community assembly mechanism of denitrifying bacteria in intensive aquaculture water.…”