Analysis of heavy metal bioremediation potential of magnetotactic bacteria isolated from industrially contaminated sites
Loading...
Date
2024-12-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
UMT, Lhr
Abstract
Heavy metal pollution presents serious environmental challenges, with the conventional remediation methods often proving insufficient for large-scale contamination management. Magnetotactic bacteria have emerged as a promising alternative due to their unique ability to accumulate and detoxify heavy metals in contaminated environments. This study explores the potential of employing Magnetotactic bacteria for bioremediation as a sustainable and cost-effective strategy to tackle heavy metal contamination in the environment. Multiple experimental approaches, including both laboratory and plant-based methods, were employed. Magnetotactic bacteria were isolated by Capillary Racetrack method. To evaluate the bacteria’s potential for heavy metal detoxification, heavy metal reduction assays were performed, such as arsenic reduction/oxidation assay, mercury reduction assay and chromium reduction assay. Phyto-bioremediation using soil-grown and hydroponic plants was assessed to evaluate the synergistic interaction between plants and bacteria in heavy metal contaminated soil. Isolates MTB2, MTB3, MTB4, MTB6 and MTB9 showed resistance against heavy metals. MTB2 and MTB4 showed highest resistance against to arsenate up to 30 mM, arsenite up to 10 mM, and mercury and chromium up to 15 mM. MTB2 and MTB6 were found to reduce arsenic while MTB4 both oxidized and reduced arsenic. Isolate MTB2 and MTB4 showed positive effects on plant growth
as well. These two isolates showed plant growth promoting characteristics by producing auxin in concentrations 252 ug/ml and 682 ug/ml, respectively, and positive results in phosphate solubilization and nitrogen fixation assays. MTB2 and MTB4 supported plant (Vigna Radiata) growth by improving root and shoot length both in presence and absence of arsenic. While with hydroponic plants (Epipremnum aureum) these isolates showed positive effects on the overall plant health in the presence of arsenic as compared to the control plants. 16S rRNA gene sequence of the bacterial isolate MTB2 showed 98.88% similarity with Magnetococcus marinus. These bacteria have the ability for heavy metal detoxification alongside supporting plant growth, which can be an ideal strategy for bioremediation of heavy metals along with plant growth promotion in industrially contaminated sites.