Microbial Biosorbents Research Articles

Microbial Biosorbent with Functionalized Curli for Efficient Recovery of Rare-Earth Elements

Microbial Biosorbent with Functionalized Curli for Efficient Recovery of Rare-Earth Elements

Adsorption of azo dye by biomass and immobilized Yarrowia lipolytica; equilibrium, kinetic and thermodynamic studies

One of the major environmental problems we have today is dye pollution, primarily caused by the textile industry. This pollution has detrimental effects on aquatic life, soil fertility, and human health. Many microbial biosorbents have been documented in the literature for the removal of a wide range of azo dyes commonly employed in the textile industry. However, Yarrowia lipolytica NBRC1658 is firstly used as both free and immobilized sorbents for the removal of Reactive yellow 18 (RY18), acid red 18 (AR18) and basic blue 41 (BB41) in this study. The effect of experimental conditions such as pH, biosorbent quantity, dye concentration, contact time, and temperature on dye removal capacity are examined. The research findings demonstrate that the adsorption capacity is higher in biomass compared to immobilized cells. The highest adsorption capacities are observed at pH 2 for RY18 and AR18, while pH 9 is optimal for BB41. Increasing the adsorbent dosage and initial concentration significantly improves the adsorption capacity. The Langmuir model best describes the adsorption process, indicating that the dye attaches to the biosorbent in a single layer, with a uniform biosorbent surface. The removal of the dye occurs through a chemical process on the biosorbent surface, as evidenced by the pseudo-second-order kinetic model. According to thermodynamic analysis, higher temperatures promote greater adsorption of dyes. Our study shows the effectiveness of Yarrowia lipolyica NBRC1658 as a biosorbent in the removal of a wide range of industrial dyes.Graphical

Biosorption as Technique for Remediation of Heavy Metals from Wastewater using Microbial Biosorbent

Biosorption, a sustainable technology, utilizes living or non-living organism and their derivative as sorbents for the removal of heavy metals from wastewater. This review explores the mechanisms and applications of biosorption in addressing environmental challenges posed by heavy metal contaminants. Pretreatment methods enhance biosorbent performance by modifying cell wall structures through physical and chemical alterations, increasing metal binding capacity. Immobilization techniques like cell entrapment and cross-linking improve biosorbent stability and reusability in continuous systems, offering controlled particle size and ease of biomass separation. Differential Scanning Calorimetry assesses biosorbent thermal stability, providing insights into performance under varying conditions. Non-living microorganisms present advantages for biosorption, including resilience to toxic wastes and extended storage capabilities. Economic considerations are crucial when evaluating biosorbent modifications for enhanced performance. The review show that biosorption using microbial biosorbents is a versatile and efficient method for heavy metal removal from wastewater, with applications in environmental remediation and sustainable water treatment practices. Future research should focus on novel biosorption strategies and optimization of existing techniques to effectively combat heavy metal pollution.

Biosorption of Triphenylmethane (TPM) Dyes by Microbial Biomass: A Review

Many organic and inorganic contaminants are present in wastewater, and releasing them into receiving waterways causes major environmental problems. The wastewater produced by numerous industries contains a significant amount of dyes; this continues to be one of the most serious ecological issues confronting public health. Unfortunately, conventional wastewater remediation methods are incapable of completely removing dyes. Biosorption is the process by which living material removes chemicals from a solution. Organic, inorganic, gaseous, liquid, or insoluble substances are examples of such substances. Absorption, adsorption, ion exchange, surface complexation, and precipitation are all mechanisms involved in this physicochemical process. It is a characteristic shared by both live and dead biomass. Triphenyl methane dyes are a significant category of commercial dyes known for their remarkable color intensity, bright red, green, and blue colors, and low lightfastness on many substrates. In contrast to live biomass, using dead biomass in biosorption is more ideal since the hazardous nature of pollutants does not affect the sorption process. There is also no need to provide nutrients or maintain a growing environment. In addition to these variables, researchers discovered that dead biomass is more efficient than active biomass at absorbing organic contaminants. This review highlighted the toxicity of dyes, principles, and theory of the adsorption process, isotherm and kinetic studies of some microbial biosorbents, and thermodynamic studies of triphenyl methane dyes adsorption.

Recent Strategies for the Remediation of Textile Dyes from Wastewater: A Systematic Review.

The presence of dye in wastewater causes substantial threats to the environment, and has negative impacts not only on human health but also on the health of other organisms that are part of the ecosystem. Because of the increase in textile manufacturing, the inhabitants of the area, along with other species, are subjected to the potentially hazardous consequences of wastewater discharge from textile and industrial manufacturing. Different types of dyes emanating from textile wastewater have adverse effects on the aquatic environment. Various methods including physical, chemical, and biological strategies are applied in order to reduce the amount of dye pollution in the environment. The development of economical, ecologically acceptable, and efficient strategies for treating dye-containing wastewater is necessary. It has been shown that microbial communities have significant potential for the remediation of hazardous dyes in an environmentally friendly manner. In order to improve the efficacy of dye remediation, numerous cutting-edge strategies, including those based on nanotechnology, microbial biosorbents, bioreactor technology, microbial fuel cells, and genetic engineering, have been utilized. This article addresses the latest developments in physical, chemical, eco-friendly biological and advanced strategies for the efficient mitigation of dye pollution in the environment, along with the related challenges.

Microbial biosorbent for remediation of dyes and heavy metals pollution: A green strategy for sustainable environment.

Toxic wastes like heavy metals and dyes are released into the environment as a direct result of industrialization and technological progress. The biosorption of contaminants utilizes a variety of biomaterials. Biosorbents can adsorb toxic pollutants on their surface through various mechanisms like complexation, precipitation, etc. The quantity of sorption sites that are accessible on the surface of the biosorbent affects its effectiveness. Biosorption's low cost, high efficiency, lack of nutrient requirements, and ability to regenerate the biosorbent are its main advantages over other treatment methods. Optimization of environmental conditions like temperature, pH, nutrient availability, and other factors is a prerequisite to achieving optimal biosorbent performance. Recent strategies include nanomaterials, genetic engineering, and biofilm-based remediation for various types of pollutants. The removal of hazardous dyes and heavy metals from wastewater using biosorbents is a strategy that is both efficient and sustainable. This review provides a perspective on the existing literature and brings it up-to-date by including the latest research and findings in the field.

DNAzyme-templated exponential isothermal amplification for sensitive detection of lead pollution and high-throughput screening of microbial biosorbents

Very low concentrations of lead (Pb2+) pollution can have far-reaching adverse impacts on human health, due to the cumulative toxicity of Pb2+. Herein, we report a DNAzyme-templated exponential isothermal amplification strategy (termed DNAzymee) for the ultrasensitive detection of Pb2+ pollution and the high-throughput screening of microbial biosorbents to remove Pb2+ pollution. DNAzyme can specifically recognize Pb2+, and this recognition event can be amplified by the subsequent exponential isothermal amplification reaction (EXPAR) and monitored by a G-quadruplex specific dye. The proposed design showed a low limit of detection (95 pM) and could identify Pb2+ pollution in different real samples with high precision. In particular, the proposed assay was used to screen Pb2+ biosorbents, and the results showed that Leuconostoc mesenteroides is a promising microbial biosorbent for removing Pb2+ pollution. Thus, the DNAzymee assay can serve as a platform to monitor lead pollution in the environment and screen efficient biosorbents for the control of lead pollution.

Statistical Analysis and Optimization of the Brilliant Red HE-3B Dye Biosorption onto a Biosorbent Based on Residual Biomass.

Using various techniques, natural polymers can be successfully used as a matrix to immobilize a residual microbial biomass in a form that is easy to handle, namely biosorbents, and which is capable of retaining chemical species from polluted aqueous media. The biosorption process of reactive Brilliant Red HE-3B dye on a new type of biosorbent, based on a residual microbial biomass of Saccharomyces pastorianus immobilized in sodium alginate, was studied using mathematical modeling of experimental data obtained under certain conditions. Different methods, such as computer-assisted statistical analysis, were applied, considering all independent and dependent variables involved in the reactive dye biosorption process. The optimal values achieved were compared, and the experimental data supported the possibility of using the immobilized residual biomass as a biosorbent for the studied reference dye. The results were sufficient to perform dye removals higher than 70–85% in an aqueous solution containing around 45–50 mg/L of reactive dye, and working with more than 20–22 g/L of prepared immobilized microbial biosorbent for more than 9.5–10 h. Furthermore, the proposed models agreed with the experimental data and permitted the prediction of the dye biosorption behavior in the experimental variation field of each independent variable.

Biosorption of Copper (II) Ions From Aqueous Solution Onto Pantoea agglomerans Isolated From Water Containing High Amount Of Boron Element

Heavy metal pollution is an serious environmental problem because they have toxic effects on living organisms. In recent years, the use of microbial biosorbents to remove heavy metal pollution have studied. Many biological materials are used to remove copper ions. In this study, the biosorption capacity of lyophilized Pantoea agglomerans for Cu (II) ions were investigated under various conditions (initial pH, contact time, initial heavy metals ion concentration). The monocomponent biosorption data have been analyzed using isotherm (Freundlich and Langmuir) and kinetic models. The highest copper uptake capacity of the biomass was obtained at the initial copper concentration of 250 mgL-1 at pH 5.0 and contact time 90th minute. The equilibrium data correlated well with the Langmuir and Freundlich model. It was found that the pseudo-second-order kinetic model fitted the experimentally obtained data. Liyofilized P. agglomerans biomass appears to be an inexpensive and efficient biosorbent for the removal of Cu (II) from aqueous solutions.

Microbial approaches for sustainable remediation of dye-contaminated wastewater: a review

The coloured effluents produced from different industries, such as textile, plastics, printing, cosmetics, leather and paper, are extremely toxic and a tremendous threat to the aquatic organisms and human beings. The removalof coloured dye pollutants from the aqueous environment is a great challenge and a pressing task. The growing demand for low-cost and efficient treatment approaches has given rise to alternative and eco-friendly methods, such as biodegradation and microbial remediation. This work summarizes the overview and current research on the remediation of dye pollutants from the aqueous environment by microbial bio-sorbents, such as bacteria, fungi, algae, and yeast. In addition, dye degradation capabilities of microbial enzymes have been highlighted and discussed. Further, the influence of various experimental parameters, such as temperature, pH, and concentrations of nutrients, and dye, has been summarized. The proposed mechanism for dye removal by microorganisms is also discussed. The object of this review is to provide a state-of-the-art of microbial remediation technologies in eliminating dye pollutants from water resources.

Isothermal and Kinetic Studies of Biosorption of Low Concentration Cr(III) from Aqueous Solution by 4 Microbial Biosorbents

Isothermal and Kinetic Studies of Biosorption of Low Concentration Cr(III) from Aqueous Solution by 4 Microbial Biosorbents

Temperature-robust and ratiometric G-quadruplex proximate DNAzyme assay for robustly monitoring of uranium pollution and its microbial biosorbents screening

Uranium pollution in environment and food chain is a serious threat to public security and human health. Herein, we proposed a temperature-robust, ratiometric, and label-free bioassay based on G-quadruplex proximate DNAzyme (G4DNAzyme), accommodating us to precisely monitor uranium pollution and biosorption. The proximity of split G-quadruplex probes was proposed to sense UO22+-activated DNAzyme activity, thus eliminating the use of chemically labeled nucleic acid probes. And the simultaneous monitoring of G-quadruplex and double-stranded structures of DNAzyme probes contributed to a ratiometric and robust detection of UO22+. Particularly, the separation of enzymatic digestion and fluorescence monitoring endued a robust and highly responsive detection of UO22+ upon the temperature of enzymatic digestion process ranged from 18° to 41 °C. Consequently, G4DNAzyme assay allowed a robust, label-free and ratiometric quantification of uranium. We demonstrated the feasibility of G4DNAzyme assay for estimating uranium pollution in water and aquatic product samples. Ultimately, G4DNAzyme assay was adopted to serve as the platform to screen bacterial species and conditions for uranium biosorption, promising its roles in uranium associated biosafety control.

Isolation of Efficient Metal-Binding Bacteria from Boreal Peat Soils and Development of Microbial Biosorbents for Improved Nickel Scavenging

Boreal peatlands with low iron availability are a potential, but rarely studied, source for the isolation of bacteria for applications in metal sorption. The present research focused on the isolation and identification of Actinobacteria from northern Finland, which can produce siderophores for metal capture. The 16S rDNA analysis showed that isolated strains belonged to Firmicutes (Bacillus sp.) and Actinobacteria (Microbacterium sp.). The culture most efficiently producing siderophores in the widest array of the media was identified as Microbacterium sp. The most appropriate media for siderophore production by the Microbacterium strain were those prepared with glucose supplemented with asparagine or glutamic acid, and those prepared with glycerol or fructose supplemented with glutamic acid. The microorganism obtained and its siderophores were used to develop Sphagnum moss-based hybrid biosorbents. It was showed that the hybrid sorbent could bind nickel ions and that the nickel removal was enhanced by the presence of siderophores. Bacterial cells did not have a significant effect on sorption efficiency compared to the use of siderophores alone. The microbial biosorbent could be applied in the final effluent treatment stage for wastewater with low metal concentrations.

Technical solutions for the safe utilization of heavy metal‐contaminated farmland in China: A critical review

AbstractChina is suffering from farmland heavy metal pollution. Different strategies have been explored in the past decades to address the problem, mainly metal removal, substitute planting, and safe farming. Safe farming aims to produce metal‐safe food crops in heavy metal‐polluted farmland without purposefully removing the excess metals. Safe farming was intended to address the soil‐borne food heavy metal issue and has been advocated as a priority solution for farmland pollution by the government. Many conventional and novel technologies have been tested for safe farming in recent years. Although most reduced heavy metals in grains, none of the technologies alone were found to be sufficient in field practice to meet national food standards. The current best practice is recognized as the combination of several agronomic measures, including pollution‐safe cultivars, optimal water management, liming, and conventional metal immobilizers. Unfortunately, field trials have not achieved a robust technical framework effective for farmland with different soil properties and climatic conditions. We propose that a practical technical framework may be biotechnology centered with a minimal use of chemical immobilizers, particularly liming and phosphate minerals. Foliar sprays and microbial biosorbents seem promising for safe farming. A biotechnology‐centered framework may largely simplify the field practice of safe farming and is more acceptable to governments and farmers.

Immobilized microbial biosorbents for heavy metals removal.

Intensive industrial and urban growth has led to the release of increasing amounts of environmental pollutants. Contamination by metals, in particular, deserves special attention due to their toxicity and potential to bioaccumulate via the food chain. Conventional techniques for the removal of toxic metals, radionuclides and precious metals from wastewater all have a number of drawbacks, such as incomplete metal extraction, high cost and risk of generating hazardous by-products. Biosorption is a cost-effective and environment-friendly technology, an alternative to conventional wastewater treatment methods. Biosorption is a metabolically independent process, in which dead microbial biomass is capable of removal and concentrating metal ions from aqueous solutions. Free microbial biosorbents are of small size and low density, insufficient mechanical stability and low elasticity, which causes problems with metal ion desorption, separation of the sorbent from the medium and its regeneration. Hence, the possibilities for the implementation of continuous biosorbent processes for metal removal in flow-type reactor systems are reduced and the practical application of biosorption in industrial conditions is limited. By immobilizing microbial biomass on suitable carriers the disadvantages of free biosorbents are eliminated and more opportunities for practical use of biosorption become available. This review examines different immobilization techniques and carriers, certain basic features and possibilities of using immobilized microbial biosorbents for the removal and concentration of metals from aqueous solutions.

Single cyanobacteria@silica porous microcapsules via a sol–gel layer by layer for heavy-metal remediation

Heavy-metal removal from industrial wastewater is a major issue. The use of microbial biosorbent is a low cost, sustainable, and efficient way for water cleaning, but the living organisms are limited by their sensitivity and fragility and subjected to water contamination by other relevant bacteria. In order to improve the use of the powerful photosynthetic prokaryote, this work focused on the development of a new protection method of cyanobacterial strains of the genus Synechococcus sp. PCC7002 by a multiple coating including an external layer made of silica. This surfacing was performed using the layer-by-layer method and different polyelectrolytes. Polydiallyldimethylammonium chloride, a cationic polymer is used as a link between the cell wall and silica shell, while polystyrene sulfonate is inserted to play a protective role against ultraviolet light irradiation. This study discloses the synthesis of a highly efficient hybrid material and the excellent protection brought by the silica material. First of all, the layers, in particular four layers, deposited around single cells offer a strong protection against very harmful UV-C light irradiation while maintaining high viability and the same bioadsorption capacity for heavy-metal ions in solution. The long-term viability of this living material and its successful use for copper and lead sequestration, confirms the possibility of exploiting encapsulated cyanobacteria to improve current biotechnologies for wastewater purification.

A New Strategy for Heavy Metal Polluted Environments: A Review of Microbial Biosorbents.

Persistent heavy metal pollution poses a major threat to all life forms in the environment due to its toxic effects. These metals are very reactive at low concentrations and can accumulate in the food web, causing severe public health concerns. Remediation using conventional physical and chemical methods is uneconomical and generates large volumes of chemical waste. Bioremediation of hazardous metals has received considerable and growing interest over the years. The use of microbial biosorbents is eco-friendly and cost effective; hence, it is an efficient alternative for the remediation of heavy metal contaminated environments. Microbes have various mechanisms of metal sequestration that hold greater metal biosorption capacities. The goal of microbial biosorption is to remove and/or recover metals and metalloids from solutions, using living or dead biomass and their components. This review discusses the sources of toxic heavy metals and describes the groups of microorganisms with biosorbent potential for heavy metal removal.

Cloning of the cnr operon into a strain of Bacillaceae bacterium for the development of a suitable biosorbent.

In this study, a potential microbial biosorbent was engineered to improve its capacity to remediate heavy metal contaminated water resources. A Bacillaceae bacterium isolated from a mining area was transformed with a plasmid carrying the (pECD312)-based cnr operon that encodes nickel and cobalt resistance. The bioadsorption ability of the transformed strain was evaluated for removal of nickel from metallurgical water relative to the wildtype strain. Results showed that transformation improved the adsorption capacity of the bacterium by 37% at nickel concentrations equivalent to 150mg/L. Furthermore it was possible to apply prediction modelling to study the bioadsorption behaviour of the transformed strain. As such, this work may be extended to the design of a nickel bioremediation plant utilising the newly developed Bacillaceae bacterium as a biosorbent.

Removal of Low Concentration Chromium (III) from Aqueous Solution with 4 Microbial Biosorbents

The low concentration Chromium (Ⅲ) adsorption was studied by 4 biosorbents (TP, XB, MY and TQ), which were isolated from Chrome-tanned leather construction section sludge. Batch experiments were carried out to investigate the effect of contact time, solution pH, biomass dosage, initial concentration of copper and temperature on biosorption efficiency. The experiment results showed that the concentration of chromium (Ⅲ) could meet the national standard (≤1.5mg/L) after treatment. The optimal pH value, mass concentration and temperature of biosorption was 4.0, 0.5g/L and 30°C, respectively. When the biosorbent were treated by [ NaOH ]= 0.3 mol/L, absorption capacitie was increased by 34.54%、23.21%、17.86% and 38.96% respectively. And from the results of SEM (Scanning electron microscope) and FT-IR (Fourier Transform infrared spectroscopy), the structure and functional groups of biosorbents was changed after the biosorption.

English

Chromium as a toxic heavy metal is of major concern due to the various health effects on human and as a pollutant to environ- ment. Chromium makes land desolate by forming toxic soluble chromium compounds in soil and water bodies. At present various microor- ganisms are used for bioremediation of chromium from soil and water bodies. The aim of present work was to bioremediate chromium from synthetic solutions by a white rot fungus Phanerochaete chrysosporium (MTCC787) using in form of viable cells, microbial biosorbent (dried cells) and immobilised cells at different physical parameters i.e. pH, temperature and medium with substrates like Citric acid, Tween 80 and EDTA.