Plant-microbe association for bioremediation of hydrocarbon substrates

Abstract

Advancement in the standards of life quality along with awareness for environmental issues and the remediation of contaminated sites has attracted attention from society. Due to high cost of mechanical and chemical techniques for hydrocarbon remediation, the utilization of biological processes is gaining considerable attention. Plant-microbe association has been widely studied during the second half of the last century yet focusing on pathogenicity and plant-saprophytic associations like nitrogen fixation, improving soil nutrient cycles and plant growth, etc. However during the last decade, the emphasis has been shifted upon microbial communication with plants for remediation of hydrocarbon-contaminated sites. The efficacy of the remediation process mainly depends on the availability and performance of microbes having degradation genes responsible for enzymatic breakdown of organic contaminants as well as chemotaxis for hydrocarbons, biofilm production, cell surface hydrophobicity, and ability to produce biosurfactants. The rhizosphere and apoplast of the plants have been testified as the potential dwellings for microbes having degradation genes, but comparatively petite information is available about the degradation activities and metabolic pathways of endophytes. Diversity of biological systems warrants deep understanding of the mechanisms involved for utilizing plant-microbe association for bioremediation of hydrocarbons. This chapter focuses on an insight of the existing biological approaches for bioremediation of hydrocarbon-contaminated sites with emphasis upon required advancements in bioremediation and phytoremediation strategies to improve efficiency.