Plant-Microbe Association-Assisted Removal of Heavy Metals and Degradation of Polycyclic Aromatic Hydrocarbons

Abstract

Contamination by polycyclic aromatic hydrocarbons and heavy metals is a rather serious problem across the world and poses a major threat to living organisms. These are considered to be carcinogens and are constituents of oil sludge. The magnitude of PAHs released into the environment has increased drastically in recent times. This is mostly due to petroleum waste or seepage during transportation of crude oil. There have been several instances of oil spills on the coasts of India and elsewhere. In northeast India, PAHs pollution is evident at the sites of drilling and refinery sites. The boiling points of high molecular weight PAHs are very high and they are almost difficult to decompose. Their hydrophobicity causes these compounds to accumulate and sequester in soil organic matter; thus, their desorption from soil limits the efficiency of biodegradation in situ. This chapter will focus on the various case studies where plant-microbe association has been used to assist bioremediation process of PAHs and heavy metals in oilcontaminated soil. Topics to be covered include how plants and microbes together effect the remediation process, bioavailability of PAHs, facilitating the movement of essential nutrients, air and water and production of biosurfactants in faster acceleration of the removal process.

Transcriptomic profiling of the flower scent biosynthesis pathway of Cymbidium faberi Rolfe and functional characterization of its jasmonic acid carboxyl methyltransferase gene

“…The functions of most of the enzymes in α-linolenic acid metabolism and the long-chain alkane biosynthesis have been reported [7, 9, 32, 33]. However, limited research was done on the PAH degradation pathway [34]. The up- and down-regulated genes in MeJA biosynthesis of blooming flowers are summarized in Tables 1 and 2.…”

Bacteria in Soil: Promising Bioremediation Agents in Arid and Semi-Arid Environments for Cereal Growth Enhancement

“…Some microorganisms can reduce metal ions such as Hg 2+ and Ag + to Hg 0 and Ag 0 and provide a perfect model for total metal removal from the soil [63]. It has been experimentally demonstrated that some rhizobacteria produce extracellular enzymes such as peroxidases, reductases, Cytochome P 450 , lacases and glutathione-S-transferase, having important roles in polycyclic aromatic hydrocarbon degradation, molecules present in crude oil and known for their toxicity and carcinogenicity [64]. Meliani [65] produced a detailed review about PGPR application in soil decontamination, focusing on the genus Pseudomonas, and some of the most important strategies used by PGPR in bioremediation such as the production of biosurfactants, biofilms, toxic metal solubilization and siderophore production.…”

Analysis of Factors Influencing Plant–Microbe Combined Remediation of Soil Contaminated by Polycyclic Aromatic Hydrocarbons

“…Therefore, the rational use of organic fertilizers helps to keep the soil healthy [33,34]. Furthermore, Sarma et al [35] focus on the various case studies where plant-microbe association has been used to assist the bioremediation process of PAHs and heavy metals in oil-contaminated soil. In contrast to the research of Sarma et al, the novelty of this present study is that the mechanisms of plant and microbial remediation of PAHS-contaminated soil under different conditions are discussed further.…”