The Interaction between Plants and Bacteria in the Remediation of Petroleum Hydrocarbons: An Environmental Perspective

Abstract

Widespread pollution of terrestrial ecosystems with petroleum hydrocarbons (PHCs) has generated a need for remediation and, given that many PHCs are biodegradable, bio- and phyto-remediation are often viable approaches for active and passive remediation. This review focuses on phytoremediation with particular interest on the interactions between and use of plant-associated bacteria to restore PHC polluted sites. Plant-associated bacteria include endophytic, phyllospheric, and rhizospheric bacteria, and cooperation between these bacteria and their host plants allows for greater plant survivability and treatment outcomes in contaminated sites. Bacterially driven PHC bioremediation is attributed to the presence of diverse suites of metabolic genes for aliphatic and aromatic hydrocarbons, along with a broader suite of physiological properties including biosurfactant production, biofilm formation, chemotaxis to hydrocarbons, and flexibility in cell-surface hydrophobicity. In soils impacted by PHC contamination, microbial bioremediation generally relies on the addition of high-energy electron acceptors (e.g., oxygen) and fertilization to supply limiting nutrients (e.g., nitrogen, phosphorous, potassium) in the face of excess PHC carbon. As an alternative, the addition of plants can greatly improve bioremediation rates and outcomes as plants provide microbial habitats, improve soil porosity (thereby increasing mass transfer of substrates and electron acceptors), and exchange limiting nutrients with their microbial counterparts. In return, plant-associated microorganisms improve plant growth by reducing soil toxicity through contaminant removal, producing plant growth promoting metabolites, liberating sequestered plant nutrients from soil, fixing nitrogen, and more generally establishing the foundations of soil nutrient cycling. In a practical and applied sense, the collective action of plants and their associated microorganisms is advantageous for remediation of PHC contaminated soil in terms of overall cost and success rates for in situ implementation in a diversity of environments. Mechanistically, there remain biological unknowns that present challenges for applying bio- and phyto-remediation technologies without having a deep prior understanding of individual target sites. In this review, evidence from traditional and modern omics technologies is discussed to provide a framework for plant–microbe interactions during PHC remediation. The potential for integrating multiple molecular and computational techniques to evaluate linkages between microbial communities, plant communities and ecosystem processes is explored with an eye on improving phytoremediation of PHC contaminated sites.

Soil Pollution by Petroleum-Derived Substances and its Bioremediation: The Effect on Aphis fabae Scop. Infestation and Antioxidant Response in Vicia faba L.

“…The seeds of the Windsor White variety of broad bean were sown in the containers at the beginning of April 2013, after earlier preparation of the soil (i.e., loosening and fertilizing) in the amounts provided in the standard seeding rate for that plant, that is, 30 seeds per container. Pre-sowing soil fertilization with NPK fertilizer ('polifoska') was applied, providing 2.88 g N, 3.77 g P, 7.16 g K and 1.30 g S per container. After sprouting, 25 plants were left in each container.…”

“…The chief sources of contamination are production processes, transportation pipeline and refinery malfunctions, tank leakages, or accidents [1]. It is commonly known that the soil contamination with PDSs constitutes a potential danger to human health and life; therefore, in recent years, efforts have been undertaken in order to find effective, inexpensive, and environmentally friendly ways to amend contaminated soils [2][3][4][5]. The most commonly recommended method is biological remediation [6][7][8].…”

A high-throughput fluorescence-based assay for rapid identification of petroleum degrading bacteria

“…These biofilms attached to the crude oil floating on the surface of the cell culture media and were anchored to the bottom of the microtiter well. Transport of crude oil through a network may allow for the efficient diffusion of petroleum hydrocarbons across highly specialized membranes embedded with monooxygenases and dioxygenases that break down petroleum hydrocarbons, such as alkB and p450cam (Gkorezis et al 2016; French et al in prep ). Petroleum compounds degraded in this manner would be dispersed within the biofilm community.…”

Introductory Chapter: Serious Pollution of Soil and Groundwater and the Necessity of Bioremediation

“…Plants and microorganisms help each other live in natural places [61,62]. For instance, plants grow by photosynthesis and their fallen leaves or withered plants are degraded by soil microorganisms.…”