
Bioremediation of Ecosystems Using Microbiological Technologies - Cytology and Genetics
Abstract The disposal of toxic metals and munitions waste represents a critical component of environmental safety and ecosystem protection. Developing new methods and technologies that can rapidly and effectively mitigate contamination and diminish its impact on the environment and human health remains an urgent priority. As an alternative to conventional physicochemical approaches for decontaminating polluted sites, bioremediation has emerged as a promising method. This process involves the transformation of hazardous chemical compounds containing toxic metals into nontoxic or less toxic substances through the activity of diverse microorganisms. Understanding bioavailability is essential for assessing the potential toxicity of metallic elements and their compounds, as well as for designing effective strategies for ecological remediation of contaminated areas. The bioavailability of metals depends on their capacity to be absorbed, chemically transformed, or metabolized by microorganisms within the contaminated environment. The primary factors influencing metal bioavailability include the chemical form of the metal, the redox potential and pH of the environment, and its ecological and physicochemical characteristics such as temperature, substrate availability, moisture, and aeration. Microorganisms themselves play a significant role in enhancing metal bioavailability through environmental acidification (protonolysis), chelate formation that binds metals, and enzymatic synthesis capable of altering the chemical state of metals via oxidation or reduction. This article examines the key processes through which microorganisms achieve bioremediation of toxic metals, namely biosorption, bioaccumulation, mobilization, and immobilization.
SpringerLink
SciTech Chronicles. . . . . . . . .Mar 8th, 2025
From the lab to the street,trust in science not deceit.. Vol II No 61 299 links Curated Scientists upends understanding of how anticancer ...

Spent brewer’s yeast as a selective biosorbent for metal recovery from polymetallic waste streams
While the amount of electronic waste is increasing worldwide, the heterogeneity of electronic scrap makes the recycling very complicated. Hydrometallurgical methods are currently applied in e-waste recycling which tend to generate complex polymetallic solutions due to dissolution of all metal components. Although biosorption has previously been described as a viable option for metal recovery and removal from low-concentration or single-metal solutions, information about the application of selective metal biosorption from polymetallic solutions is missing. In this study, an environmentally friendly and selective biosorption approach, based on the pH-dependency of metal sorption processes is presented using spent brewer’s yeast to efficiently recover metals like aluminum, copper, zinc and nickel out of polymetallic solutions. Therefore, a design of experiment (DoE) approach was used to identify the effects of pH, metal, and biomass concentration, and optimize the biosorption efficiency for each individual metal. After process optimization with single-metal solutions, biosorption experiments with lyophilized waste yeast biomass were performed with synthetic polymetallic solutions where over 50% of aluminum at pH 3.5, over 40% of copper at pH 5.0 and over 70% of zinc at pH 7.5 could be removed. Moreover, more than 50% of copper at pH 3.5 and over 90% of zinc at pH 7.5 were recovered from a real polymetallic waste stream after leaching of printed-circuit boards. The reusability...
Frontiers
A dozen exotic bacteria are found to passively collect rare earth elements from wastewater
Rare earth elements (REEs) are a group of 17 chemically similar metals, which got their name because they typically occur at low concentrations (between 0.5 and 67 parts per million) within Earth's crust. Because they are indispensable in modern technology such as light-emitting diodes, mobile phones, electromotors, wind turbines, hard disks, cameras, magnets and low-energy lightbulbs, the demand for them has increased steadily over the past few decades, and is predicted to rise further by 2030.
Phys.org