Bioremediation strategies and mechanisms of bacteria for resistance against heavy metals: a review

Abstract

Industrial activities often generate by-products that are difficult to degrade, harmful to the environment and, toxic to most of the life forms on earth. Heavy metals are toxic elements that usually present in industrial effluents whose effective management in an eco-friendly manner is important. The treatment of metal-contaminated water through the conventional method of precipitation, ion exchange, electrochemical and reverse osmosis is costly and also likely to generate secondary pollutants. In this review study, we focus on the advantage of bacterial bioremediation to deal with metal toxicity. Bacterial bioremediation offers an eco-friendly and cost-effective alternative for treatment of metal contaminated industrial effluent. Bacteria are considered one of the important microbial systems to be employed for bioremediation purposes. Bacteria utilize the mechanisms of biosorption and bioaccumulation which involve ATP-dependent substrate specific sequestration to remediate the contaminants through redox reactions and enzyme-transformation methods. Bacterial cell wall offers potential chemisorption sites for binding and transportation of metal ion to the bacterial cytoplasm. The potential of bacterial bioremediation can be improved by adopting strategies, providing favorable environment, and using stress adapted strains consisting high metabolic activity, metal selectivity, membrane transport system, efficient biocatalytic and chaperone production ability. The bioremediation efficiency of bacteria is expected to improve many folds through the techniques of genetic modifications involving mutation, plasmid exchange and transposons etc. This study may throw light on the detailed mechanism and strategies adapted by bacteria for the bioremediation of toxic heavy metal ions and open a new way to handle metal toxicity efficiently.

HIGHLIGHTS

• Heavy metal toxicity is a global issue that requires effective treatment.

• Physical and Chemical methods are least effective and costly to detoxify heavy metals.

• Toxic metal ions can be removed from the environment using a variety of chemical and physical techniques, but these techniques haven’t been proven to be good or effective ways to treat heavy metals.

• The removal of toxic pollutant from atmosphere through biological system without creating any secondary pollutant is known as bioremediation.

• Bioremediation is a new approach that might be found cost-effective and efficient for the metal treatment.

Keywords:

• Heavy metals
• toxicity
• bioremediation
• bacteria
• environment 

Acknowledgements

We are thankful to the Department of Biotechnology, Hemvati Nandan Bahuguna Garhwal University, Srinagar (Uttarakhand), and National Scheduled Castes Finance and Development Corporation (NSFDC) India, for providing the facility for this work.

Author contributions

Anjali Patil: Bioremediation data collection, material preparation, and writing-original draft. Mamta Arya: Suggested the theme of the work, and supervise. Sudip Chakraborty: Helps in material preparation, review and editing. Yuvraj Yadav: Editing, and data analysis. Bhavtosh Sharma: Formatting and editing. Sachin Singh: Data analysation and formatting.

Disclosure statement

No potential conflict of interest was reported by the authors.

Consent to publication

All authors give their consent to publish this paper.

Data availability statement

The authors affirm that the article and its supplemental materials have the sufficient data needed to support the findings of this study.

Additional information

Funding

No funding available for this research