Microbial and Plant-Assisted Bioremediation of Heavy Metal Polluted Environments: A Review

Abstract

Environmental pollution from hazardous waste materials, organic pollutants and heavy metals, has adversely affected the natural ecosystem to the detriment of man. These pollutants arise from anthropogenic sources as well as natural disasters such as hurricanes and volcanic eruptions. Toxic metals could accumulate in agricultural soils and get into the food chain, thereby becoming a major threat to food security. Conventional and physical methods are expensive and not effective in areas with low metal toxicity. Bioremediation is therefore an eco-friendly and efficient method of reclaiming environments contaminated with heavy metals by making use of the inherent biological mechanisms of microorganisms and plants to eradicate hazardous contaminants. This review discusses the toxic effects of heavy metal pollution and the mechanisms used by microbes and plants for environmental remediation. It also emphasized the importance of modern biotechnological techniques and approaches in improving the ability of microbial enzymes to effectively degrade heavy metals at a faster rate, highlighting recent advances in microbial bioremediation and phytoremediation for the removal of heavy metals from the environment as well as future prospects and limitations. However, strict adherence to biosafety regulations must be followed in the use of biotechnological methods to ensure safety of the environment.

Liquid chromatography–tandem mass spectrometry analysis of aristolochic acids in soil samples collected from Serbia: Link to Balkan endemic nephropathy

“…It is also reasonable to speculate that remediation could be carried out with selected microbes. A similar bioremediation process was also observed for polycyclic aromatic hydrocarbon compounds and heavy metals . Our results also agree with those of a previous study that AA‐II is less stable than AA‐I in soil, based on the lower levels of AA‐II remaining in all the experimental soil sets …”

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

“…Therefore, the remediation of soil and groundwater must be implemented in parallel with efforts to decrease emissions. Various remediation processes such as bioventing, bioremediation with Fenton reactions, and oxygen release compounds (ORC) have been developed, and those conventional processes are successfully applied to contamination spread in a narrow area [41,42]. However, they are inadequate when pollution has spread in a large area because they are expensive processes.…”

Bioremediation of Landfill Leachate Using Isolated Bacterial Strains

“…Soil was chosen as a carrier matrix for microorganisms as it is low cost and has been previously used in bioremediation studies treating toxic compounds [21], [23]. Columns containing un-inoculated soil and soil containing the mastermix of microorganisms were compared.…”

“…Bioremediation, the process of biologically removing a pollutant from the environment [21,22,23], is a cost-effective and environmentally friendly method of mineralizing most organic compounds in LFL. It is carried out by naturally occurring microorganisms which contribute to degradation and stabilisation of waste in landfill sites by reducing organic compounds to CO 2 and CH 4 under anaerobic conditions [24].…”

“…Isolating microorganisms capable of bioremediating the most common components of LFL, ammonia, phosphate, nitrates, biological oxygen demand (BOD) and chemical oxygen demand (COD) and growing them as pure cultures may result in these strains being harnessed as a costeffective, natural method of LFL treatment [21,22,23]. The use of microorganisms in bioreactors to treat landfill leachate has been widely reported in the literature particularly in rotating biological contractors, sequence batch reactors and moving-bed biofilm reactors where they have been used for the bioremediation of pollutants including xenobiotic organic compounds (XOC"s) and Polycyclic aromatic hydrocarbons (PAHs), as well as removing ammonia [19,28,29,30].…”