Arsenic removal technologies and future trends: A mini review

Nitrate, arsenic and fluoride removal by electrodialysis from brackish groundwater.

A review of green remediation strategies for heavy metal contaminated soil

A review on sources, identification and treatment strategies for the removal of toxic Arsenic from water system

A review on arsenic removal from coal combustion: Advances, challenges and opportunities

Phytobial remediation is an innovative tool that uses plants and microbes to mitigate Arsenic (As) contamination of the environment. Recently, plant growth-promoting bacteria (PGPB) that assists phytoremediation has been highly touted for both improving plant metal tolerance and promoting plant growth while achieving the goal of large-scale removal of As. This review focuses on the PGPB characteristics influencing plants and the mechanisms in which they function to overcome/lessen As-induced adversities. Several recent examples of mechanisms responsible for increasing the availability of As to plants and coping with As stresses facilitated by PGPB will be reviewed. Although drawbacks to phytoremediation have been reported, encouraging results have been developed with regular monitoring. Introducing PGPB-assisted phytoremediation of As in a field requires an assessment of the environmental effects of PGPB, especially with respect to the impacts on indigenous bacteria.

The role of plant growth promoting bacteria on arsenic removal: A review of existing perspectives

Arsenic (As) is an increasing threat across the globe, widely known as a non-threshold carcinogen, and it is reaching harmful values in several areas of the world. In this study, the effect of plant growth promoting bacteria (Microbacterium foliorum) on inorganic arsenic (Arsenate) phytoremediation by Melastoma malabathricum plants was investigated through histological analysis and proteome profiling of the M. malabathricum plants. Two-dimensional gel electrophoresis and transmission electron microscopy were used to conduct the proteome and histological analysis. When arsenic-treated cells were compared to untreated cells, substantial changes were found (1) severely altered the morphology of the cells, intensely disturbed; (2) the cell wall was thicker; (3) drastically changed the cytoplasm, the cells were polygonal in shape, different in size (scattered), and relatively dense. Compared to the control group, the ultra-structure of the root cells of the control group revealed intact cytoplasm, vacuole, and cell wall under exposure to As + bacteria that had a minor effect on the cell form. To further understand As + bacteria interaction, proteome profiling of the root cell was analyzed. The As-induced oxidative stress enrichment was confirmed by the up-regulation of tubulin, nucleoside diphosphate kinase, and major allergen during As + bacteria exposure It was observed that the profusion of proteins involved in defence, protein biogenesis, signaling, photosynthesis, nucleoside and energy metabolism was greater in As + bacteria as compared to the rooting out of As only. Overall, it can be obviously seen that the current study demonstrates the effectiveness of phytoremediation by M. foliorum on proteins involved and responsive 
pathways in dealing with As toxicity in M. malabathricum plant.

Histological and proteome analyses of Microbacterium foliorum-mediated decrease in arsenic toxicity in Melastoma malabathricum

The Microbacterium foliorum species is known for its ability to produce siderophores which, in synergy with the plant root, can effectively affect the rates of arsenate-to-arsenite mobilization, arsenic uptake, and translocation. This study investigates M. foliorum, a plant growth-promoting bacterium (PGPB), in the absorption of arsenic (As) by Melastoma malabathricum plant from contaminated soil. The current study demonstrates M. foliorum phytoremediation’s efficacy in terms of As tolerance, removal, and toxicity in the M. malabathricum plant. For an observation period of 90 days, growing plants were treated with M. foliorum in arsenic-contaminated soil. The morphological trait, pH of soil, and potential advantage induced by M. foliorum on M. malabathricum were evaluated. Plants did not display any noticeable signs of toxicity, however, the root and stem length were significantly increased in the presence of M. foliorum. The Bioconcentration Factor (BCF) was increased in plants inoculated with M. foliorum by 0.3 times, the Transfer Factor (TF) of As in the M. malabathricum plants decreased, whether in the presence or absence of PGPB. The As phytoremediation treatment with M. foliorum also enhanced uptake of As in root (by 26%) and shoot (by 22%) than in the other two (A2 and control) phytoremediation treatments. This shows that M. foliorum inoculation reduced As toxicity through substantial reduction of the adverse stress effects, increased stem and root fresh and dry weight. 

Sadiya Alka

Papers

Arsenic removal technologies and future trends: A mini review

The role of plant growth promoting bacteria on arsenic removal: A review of existing perspectives

Histological and proteome analyses of Microbacterium foliorum-mediated decrease in arsenic toxicity in Melastoma malabathricum

Assessment of plant growth promotion properties and impact of Microbacterium foliorum for arsenic removal in Melastoma malabathricum