Biosorption Potential Research Articles

Biosorption performance toward Co(II) and Cd(II) by irradiated Fusarium solani biomass.

Fusarium solani biomass plays a significant role in water pollution remediation due to its ability to sequester heavy metals, particularly cobalt (Co(II)) and cadmium (Cd(II)), which pose severe environmental and health risks. This study aimed to identify fungi from sewage-contaminated sites and evaluate their efficiency in absorbing and reducing Co(II) and Cd(II) ions. The biosorption potential of irradiated Fusarium solani biomass for removing Co(II) and Cd(II) ions from aqueous solutions was investigated. Six fungal isolates were screened, and the most promising isolate, identified as F. solani, was selected for further research. The biomass was exposed to different gamma irradiation doses (0, 1, 3, and 5kGy), and its biosorption efficiency was assessed. The highest biosorption efficiencies were observed with the biomass exposed to 5kGy (FS-5), achieving 37% for Co(II) and 90% for Cd(II) removal within 25min. The surface area of the biosorbent increased from 13.12m2g-1 for unexposed biomass (FS-0) to 34.87m2g-1 for FS-5, enhancing the biosorption capacity. The adsorption kinetics followed a pseudo second order model with high correlation coefficients (R2 > 0.993), indicating chemisorption as the rate-limiting step. Isotherm studies showed that the Langmuir model provided a better fit to the experimental data, with maximum adsorption capacities of 4.44mgg-1 for Co(II) and 21.00mgg-1. This study provides valuable insights into the effective removal of Cd and Co from polluted sites, underscoring the potential of developing eco-friendly and cost-effective bioremediation approaches.

UV-C Exposure Enhanced the Cd2+ Adsorption Capability of the Radiation-Resistant Strain Sphingomonas sp. M1-B02.

Microbial adsorption is a cost-effective and environmentally friendly remediation method for heavy metal pollution. The adsorption mechanism of cadmium (Cd) by bacteria inhabiting extreme environments is largely unexplored. This study describes the biosorption of Cd2+ by Sphingomonas sp. M1-B02, which was isolated from the moraine on the north slope of Mount Everest and has a good potential for biosorption. The difference in Cd2+ adsorption of the strain after UV irradiation stimulation indicated that the adsorption reached 68.90% in 24 h, but the adsorption after UV irradiation increased to 80.56%. The genome of strain M1-B02 contained antioxidant genes such as mutL, recA, recO, and heavy metal repair genes such as RS14805, apaG, chrA. Hydroxyl, nitro, and etceteras bonds on the bacterial surface were involved in Cd2+ adsorption through complexation reactions. The metabolites of the strains were significantly different after 24 h of Cd2+ stress, with pyocyanin, L-proline, hypoxanthine, etc., being downregulated and presumably involved in Cd2+ biosorption and upregulated after UV-C irradiation, which may explain the increase in Cd2+ adsorption capacity of the strain after UV-C irradiation, while the strain improved the metabolism of the antioxidant metabolite carnosine, indirectly increasing the adsorption capacity of the strains for Cd2+.

Mycoremediation of heavy metals by Curvularia lunata from Buckingham Canal, Neelankarai, Chennai.

The spread and mobilization of toxic heavy metals in the environment have increased to a harmful level in recent years as a result of the fast industrialization occurring all over the world to meet the demands of a rising population. This research aims to analyze and evaluate the mycoremediation abilities of fungal strains that exhibit tolerance to heavy metals, gathered from water samples at Buckingham Canal, Neelankarai, Chennai. Water samples were examined for heavy metal analysis, and the highest toxic heavy metals, Zn, Pb, Mn, Cu, and Cr, were recorded. Three fungal strains were isolated and named EBPL1000, EBPL1001, and EBPL1002 were selected by primary screening (100ppm) for further studies. Out of three fungal isolates, EBPL1000 grew in all five heavy metal concentrations and showed 2100ppm as the highest Maximum Tolerance Concentration toward Lead, 2000ppm tolerance in Zinc and Manganese, 1700ppm in Chromium, and 1500ppm in copper, respectively. The fungal isolate EBPL1000 was identified as Curvularia lunata with 100% percentage identity and query coverage. The Biosorption result reveals that lead is the highest biosorbed heavy metal with 79.99% at 100ppm concentration while copper is the lowest biosorbed with 24.11% heavy metal at 500ppm concentration. The uptake of Manganese by Curvularia lunata biomass was the highest (5.64mg/g) of all heavy metal's uptake at 100ppm concentration. The lowest uptake of heavy metals was copper (0.43mg/g) at 500ppm concentration, and the growth profile study under heavy metals stress conditions shows the order of Pb > Mn > Zn > Cr > Cu at 60h of time intervals at 100ppm concentration. In addition to the research, FTIR analysis and Molecular Docking studies provide credence to the idea that Curvularia lunata has high biosorption potential and uptake or removal of toxic heavy metals at low cost and in an eco-friendly way from the contaminated environment.

Run-off impacts on Arctic kelp holobionts have strong implications on ecosystem functioning and bioeconomy

Kelps (Laminariales, Phaeophyceae) are foundation species along Arctic rocky shores, providing the basis for complex ecosystems and supporting a high secondary production. Due to ongoing climate change glacial and terrestrial run-off are currently accelerating, drastically changing physical and chemical water column parameters, e.g., water transparency for photosynthetically active radiation or dissolved concentrations of (harmful) elements. We investigated the performance and functioning of Arctic kelp holobionts in response to run-off gradients, with a focus on the effect of altered element concentrations in the water column. We found that the kelp Saccharina latissima accumulates harmful elements (e.g., cadmium, mercury) originating from coastal run-off. As kelps are at the basis of the food web, this might lead to biomagnification, with potential consequences for high-latitude kelp maricultures. In contrast, the high biosorption potential of kelps might be advantageous in monitoring environmental pollution or potentially extracting dissolved rare earth elements. Further, we found that the relative abundances of several kelp-associated microbial taxa significantly responded to increasing run-off influence, changing the kelps functioning in the ecosystem, e.g., the holobionts nutritional value and elemental cycling. The responses of kelp holobionts to environmental changes imply cascading ecological and economic consequences for Arctic kelp ecosystems in future climate change scenarios.

Carbothermal Shock Derived Electrochemical Regeneration of Spent Biochar for Remediation of Ciprofloxacine Contaminated Water

Biochar, derived from waste biomass, is a potent material for carbon dioxide sequestration, owing to its stable, non-degradable aromatic structure [1]. Biochar is found to have advantageous characteristics, such as a unique pore structure, large specific surface area, complex surface-active functional groups, and stable chemical properties. These properties make biochar as a high potential biosorbent for removal of pollutants from water [2]. Meanwhile, the escalating use of pharmaceuticals has led to pervasive environmental residues, posing public health risks. Specifically, antibiotic contamination risks augmenting antibiotic resistance, underscoring the need for efficient wastewater treatment methods [3]. However, current wastewater treatment plant(WWTP) based on biological treatment was not effectively eliminate this types of waste in the water and it is necessary to investigate efficient method for removal of antibiotics from wastewater.This study explores the use of biochar for ciprofloxacin (CIP) removal from water and introduces a novel electrochemical biochar regeneration technique. We utilized sludge from chemical plants to produce biochar through standard and alkali-activated pyrolysis, yielding CB (normal pyrolysis) and CAB (alkali activated pyrolysis) types with distinct physicochemical properties. CAB, with an exceptionally high surface area (~2330 m²/g) and carbon purity (95.4%), demonstrated superior CIP adsorption capacity (~550 mg/g). We investigated the CIP adsorption isotherm, kinetics and thermodynamics to elucidate the underlying mechanisms, which appear dominated by π-π and electrostatic interactions facilitated by the high pyrolysis temperatures reducing oxygen-containing groups on the biochar. After the biochar became saturated with CIP, we regenerated it using joule heating in Ar atmosphere, employing the carbothermal shock method for rapid, short-duration temperature increases [4]. In contrast to traditional CTS which can sometimes lead to structural damage by directly heating the material on the carbon substrate [5], we used radiant heat from the CTS process to ensure controlled temperature elevation. This modified approach maintains the structural integrity of the biochar by avoiding direct contact between the biochar and the carbon substrate while facilitating the regeneration process. Additionally, this method facilitates the physical separation of the biochar from the carbon substrate, enhancing the recovery and reuse of biochar. Such an approach contributes to the efficient regeneration of biochar and environmentally friendly processing. We examined parameters such as distance from the substrate and duration to optimize the regeneration conditions. Ultimately, we assessed the efficacy of the CIP adsorption by the regenerated biochar. Traditional thermal treatments for biochar regeneration are energy-intensive and time-consuming. We propose an innovative approach using joule heating under a nitrogen atmosphere, employing carbothermal shock for rapid, efficient regeneration. By optimizing parameters such as voltage and duration, we identified ideal conditions for regenerating biochar, significantly enhancing its CIP adsorption efficacy. This study not only highlights the potential of biochar in environmental remediation but also introduces an energy-efficient regeneration method, contributing to sustainable pollution management solutions.

Exploring biosorption potential of cow dung derived novel strain Cellulosimicrobium cellulans KHP3 in the remediation of Chromium (Cr), Copper (Cu) and Zinc (Zn)

The present work reports the bioremediation ability of cow dung isolated bacterial strain Cellulosomicrobium cellulans KHP3 identified by applying PCR amplification and rRNA gene sequencing. The potential of C. cellulans KHP3 to tolerate different concentrations of heavy metals was investigated by growing the novel strain on nutrient agar medium supplemented with increasing concentrations (in ppm) of heavy metals i.e., Chromium (50–1500) Copper (50–200), and Zinc (50–200). The strain KHP3 displayed maximum tolerable concentration (MTC) of 1500 ppm against Chromium while 200 ppm was observed for Copper and Zinc. The strain KHP3 was found to be very effective in the removal of Chromium as indicated by 59.8% removal percentage followed by Zinc (36.6%) and Copper (20.4%) after 72 h of incubation at 37 °C. The higher biosorption capacity of our strain was achieved against Chromium (349.6 mg/g) followed by Zinc (198.8 mg/g) and Copper (58.6 mg/g) which reflects the potential of bacterial strain to absorb a greater amount of heavy metal ions. Following bioremediation assay, the strain C. cellulans KHP3 was subjected to FE-SEM coupled with EDS and FTIR to confirm surface morphological and physiochemical changes resulting from heavy metal adsorption. FE-SEM observation provided substantial information on the immobilization ofChromium, Copperand Zincions on the bacterial cell surface while EDS peaks revealed surface bio-sorption of these heavy metals. The binding of heavy metals on the surface of C. cellulans KHP3 was proved through FTIR study which revealed the involvement of various functional groups acting as surface ligand such as hydroxyl, carbonyl, and amine present on bacterial surface. Moreover, studies based on Freundlich, Langmuir, and Temkin isotherm models were also done to further validate the adsorption mechanism of our strain. The significant R 2 values of 0.9983 and 0.9852 observed in case of Chromium and Zinc respectively depicted monolayer adsorption. On the other hand, R 2 value 0.7959 in case of Copper significantly revealed multilayer adsorption mechanism. The findings highlight the biosorption ability of Cellulosomicrobium cellulans KHP3 for heavy metals that may be explored in the remediation of environmental pollutants.

Kinetic and thermodynamic analysis of alizarin Red S biosorption by Alhagi maurorum: a sustainable approach for water treatment

Synthetic dyes, such as Alizarin Red S, contribute significantly to environmental pollution. This study investigates the biosorption potential of Alhagi maurorum biosorbent for the removal of Alizarin Red S (ARS) from aqueous solutions. Fourier transform infrared spectroscopy (FTIR) was used to analyze the biosorbent’s adsorption sites. Various parameters were optimized to maximize dye adsorption. An optimal removal efficiency of 82.26% was attained by employing 0.9 g of biosorbent with a 25 ppm dye concentration at pH 6 and 60 °C over 30 min. The data were modeled using various isothermal and kinetic models to understand the adsorption behavior. Thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic. The pseudo-second-order kinetic model best described the data, indicating chemisorption as the rate-limiting step. The data matched best to the Langmuir model, indicating that the adsorption occurs as a monolayer on uniform surfaces with a finite number of binding sites. The model showed a strong correlation (R² = 0.991) and a maximum adsorption capacity (qmax) of 8.203 mg/g. Principal component analysis (PCA) identified temperature as the dominant factor, with the primary component, PC1 capturing 100% of its effect. The mechanisms involved in ARS biosorption on A. maurorum include electrostatic interactions, hydrogen bonding, hydrophobic interactions, dipole-dipole interactions, and π-π stacking. Alhagi maurorum showed promising potential for biosorbing toxic dyes from contaminated water, suggesting further investigation for practical applications.

Binary Biosorption of Cu(II) and Cr(VI) by Naturally Formed Biofilm Matrices

Water pollution poses a significant ecological threat, contributing to the widespread degradation of aquatic ecosystems. Among the pollutants, heavy metals pose severe risks to both organisms and human health, emphasizing the urgent need for effective pollution control technologies. Biosorption presents a promising, cost-effective, and environmentally friendly solution to mitigate heavy metal contamination. Biofilms, consisting of microbial communities, have emerged as potential biosorbents for heavy metals. Since heavy metals can exist as cations and anions concurrently in aquatic environments, understanding their behavior in binary systems is essential for biosorption strategies. This study focuses on the binary biosorption of Cu(II) and Cr(VI), representing cationic and anionic heavy metals. Specific adsorption sites are identified by analyzing adsorption kinetics, isotherms, and IR spectra of biofilms. The results indicate that biofilms, in a binary scenario, demonstrate nearly identical adsorption capacities for Cu(II) and Cr(VI). Moreover, the adsorption process follows the Langmuir adsorption model, emphasizing the potential of biofilms as effective biosorbents for the simultaneous removal of cationic and anionic heavy metals. This study advocates for a sustainable approach to heavy metal remediation through the utilization of biofilms.

Biosynthesis and Biosorption Potential of AgNPs from A. Indica Extract for Removal of Cr (VI)

Biosynthesis and Biosorption Potential of AgNPs from <i>A. Indica</i> Extract for Removal of Cr (VI)

Removal of hazardous Aniline Blue dye using a potential Biosorbent – Hen feather

In this research we have successfully removed a highly toxic dye, “Aniline Blue”, from its aqueous solution employing an adsorbent, Hen Feathers. The dye adsorption over Hen Feather was comprehensively studied over ranges of contact time, pH, concentration, and adsorbent dosage, and the optimum values were evaluated. In order to understand the behaviour of the adsorption system, various isotherm models were evaluated at temperatures of 30, 40 and 50 °C. The data obtained from contact time studies were used to test pseudo-first and pseudo-second order kinetic models and it was found that the adsorption follows pseudo-second-order kinetics. Using the Langmuir constant, b, thermodynamic parameters including ΔG°, ΔH° and ΔS° were calculated and it was ascertained that the process is endothermic (positive ΔH°), involves an increase in disorder (positive ΔS°) and is spontaneous (negative ΔG°). The values of the separation factor (r) also confirmed a favourable adsorption process at all three temperatures studied. Overall, it is affirmed that the adsorbent, Hen Feather, acts as highly potent scavenger to remove the dye Aniline Blue from its aqueous solutions.

Responses of Dunaliella sp. AL-1 to chromium and copper: Biochemical and physiological studies

Microalgae have gained recognition as versatile candidates for the remediation of heavy metals (HMs). This study investigated the biosorption potential of Dunaliella sp. AL1 for copper (Cu(II)) and hexavalent chromium (Cr(VI)) in aqueous solutions. The marine microalga Dunaliella sp. AL1 was exposed to half-sublethal concentrations of both metals in single and bimetallic systems, and responses in algal growth, oxidative stress, photosynthetic pigment production, and photosynthetic performance were evaluated. Cu and/or Cr exposure increased the generation of reactive oxygen species (ROS) in microalgae cells but did not impact algal growth. In terms of photosynthesis, there was a decrease in chlorophylls and carotenoids production in the microalgae culture treated with Cr, either alone or in combination with Cu. The study recorded promising metal removal efficiencies: 26.67%–20.11% for Cu and 94.99%–95.51% for Cr, in single and bimetallic systems, respectively. FTIR analysis revealed an affinity of Cu and Cr ions towards aliphatic/aldehyde C–H, N–H bending, and phosphate groups, suggesting the formation of complex bonds. Biochemical analysis of microalgae biomass collected after the removal of Cr alone or in combination with Cu showed a significant decrease in total carbohydrate content and soluble protein levels. Meanwhile, higher lipid accumulation was recorded and evidenced by BODIPY 505/515 staining. Fatty acid composition analysis by GC revealed a modulation in lipid composition, with a decrease in the ratio of unsaturated fatty acids (UFA) to saturated fatty acids (SFA), in response to Cu, Cr, and Cu–Cr exposure, indicating the suitability of the biomass for sustainable biofuel production.

Adsorptive removal of Ni(II) using nickel-resistant dead S. cerevisiae AJ208

Recent trends in environmental pollution urge for immediate resolution of Ni(II) elimination as industrial effluents from wastewater. From that perspective, bioremediation substantiates an effective practice for eliminating Ni(II) using a potential biosorbent. In this study, the Ni(II) elimination efficacy of 5000 mg/L Ni(II) resistant dead S. cerevisiae AJ208 is elaborately explained with physical parameter optimization and established by SEM-EDAX analysis. FTIR study validated that carboxyl, hydroxyl, carbonyl, and amine are accountable for biosorption. Investigational findings fit well in the Langmuir model, representing a single-layered adsorption process. Obtained Langmuir maximum adsorption capability is 201.61 mg/g. The pseudo-second-order model fits well with the experimental data, which signifies chemical adsorption. The experimental data have been analyzed using statistics and a genetic algorithm (GA). Ni(II) resistant dead S. cerevisiae AJ208 could substitute the expensive elimination techniques to decontaminate Ni(II) from industrial wastewater.

Genome and pan-genome analysis of a new exopolysaccharide-producing bacterium Pyschrobacillus sp. isolated from iron ores deposit and insights into iron uptake.

Bacterial exopolysaccharides (EPS) have emerged as one of the key players in the field of heavy metal-contaminated environmental bioremediation. This study aimed to characterize and evaluate the metal biosorption potential of EPS produced by a novel Psychrobacillus strain, NEAU-3TGS, isolated from an iron ore deposit at Tamra iron mine, northern Tunisia. Genomic and pan-genomic analysis of NEAU-3TGS bacterium with nine validated published Psychrobacillus species was also performed. The results showed that the NEAU-3TGS genome (4.48 Mb) had a mean GC content of 36%, 4,243 coding sequences and 14 RNA genes. Phylogenomic analysis and calculation of nucleotide identity (ANI) values (less than 95% for new species with all strains) confirmed that NEAU-3TGS represents a potential new species. Pangenomic analysis revealed that Psychrobacillus genomic diversity represents an "open" pangenome model with 33,091 homologous genes, including 65 core, 3,738 shell, and 29,288 cloud genes. Structural EPS characterization by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy showed uronic acid and α-1,4-glycosidic bonds as dominant components of the EPS. X-ray diffraction (XRD) analysis revealed the presence of chitin, chitosan, and calcite CaCO3 and confirmed the amorphous nature of the EPS. Heavy metal bioabsorption assessment showed that iron and lead were more adsorbed than copper and cadmium. Notably, the optimum activity was observed at 37°C, pH=7 and after 3 h contact of EPS with each metal. Genomic insights on iron acquisition and metabolism in Psychrobacillus sp. NEAU-3TGS suggested that no genes involved in siderophore biosynthesis were found, and only the gene cluster FeuABCD and trilactone hydrolase genes involved in the uptake of siderophores, iron transporter and exporter are present. Molecular modelling and docking of FeuA (protein peptidoglycan siderophore-binding protein) and siderophores ferrienterobactine [Fe+3 (ENT)]-3 and ferribacillibactine [Fe+3 (BB)]-3 ligand revealed that [Fe+3 (ENT)]-3 binds to Phe122, Lys127, Ile100, Gln314, Arg215, Arg217, and Gln252. Almost the same for [Fe+3 (ENT)]-3 in addition to Cys222 and Tyr229, but not Ile100.To the best of our knowledge, this is the first report on the characterization of EPS and the adsorption of heavy metals by Psychrobacillus species. The heavy metal removal capabilities may be advantageous for using these organisms in metal remediation.

Unlocking Cd(II) biosorption potential of Candida tropicalis XTA 1874 for sustainable wastewater treatment

Cd(II) is a potentially toxic heavy metal having carcinogenic activity. It is becoming widespread in the soil and groundwater by various natural and anthropological activities. This is inviting its immediate removal. The present study is aimed at developing a Cd(II) resistant strain isolated from contaminated water body and testing its potency in biological remediation of Cd(II) from aqueous environment. The developed resistant strain was characterized by SEM, FESEM, TEM, EDAX, FT-IR, Raman Spectral, XRD and XPS analysis. The results depict considerable morphological changes had taken place on the cell surface and interaction of Cd(II) with the surface exposed functional groups along with intracellular accumulation. Molecular contribution of critical cell wall component has been evaluated. The developed resistant strain had undergone Cd(II) biosorption study by employing adsorption isotherms and kinetic modeling. Langmuir model best fitted the Cd(II) biosorption data compared to the Freundlich one. Cd(II) biosorption by the strain followed a pseudo second order kinetics. The physical parameters affecting biosorption were also optimized by employing response surface methodology using central composite design. The results depict remarkable removal capacity 75.682 ± 0.002% of Cd(II) by the developed resistant strain from contaminated aqueous medium using 500 ppm of Cd(II). Quantitatively, biosorption for Cd(II) by the newly developed resistant strain has been increased significantly (p < 0.0001) from 4.36 ppm (non-resistant strain) to 378.41 ppm (resistant strain). It has also shown quite effective desorption capacity 87.527 ± 0.023% at the first desorption cycle and can be reused effectively as a successful Cd(II) desorbent up to five cycles. The results suggest that the strain has considerable withstanding capacity of Cd(II) stress and can be employed effectively in the Cd(II) bioremediation from wastewater.

Mechanism of Biological Transport and Transformation of Copper, Cadmium, and Zinc in Water by Chlorella

This study investigates the effectiveness of Chlorella vulgaris in treating copper, cadmium, and zinc in aqueous solutions; the aim of this study was to examine the effects of various factors on the adsorption capacity of Chlorella in water. This study explored the intra- and extracellular adsorption and accumulation patterns of copper (Cu(II)), cadmium (Cd(II)), and zinc (Zn(II)), revealing their molecular response mechanisms under the most suitable conditions. The adsorption capacity of Chlorella to Cu(II), Cd(II), and Zn(II) in water was 93.63%, 73.45%, and 85.41%, respectively. The adsorption mechanism for heavy metals is governed by both intracellular and extracellular diffusion, with intracellular absorption serving as a supplement and external uptake predominating. XRD, XPS, FTIR, SEM-EDX, and TEM-EDX analyses showed that there would be the formation of precipitates such as Cu2S, CuS2, CdS, and ZnSO4. The adsorption of Cu(II) involves its simultaneous reduction to Cu(I). Moreover, specific functional groups present on the cellular surface, such as amino, carboxyl, aldehyde, and ether groups, interact with heavy metal ions. In view of its efficient heavy metal adsorption capacity and biosafety, this study recommends Chlorella as a potential biosorbent for the bioremediation and environmental treatment of heavy metal contaminated water in the future.

Bacterial Bisorption as an Approach for the Bioremediation of Chromium Contaminated Soils: An Overview

Study’s Novelty/Excerpt This study presents comprehensive overview of the roles of various bacterial genera, including Alcaligens, Achromobacter, and Bacillus, in the biosorption of chromium from contaminated soils, highlighting specific factors influencing biosorption efficiency. It uniquely addresses the optimization of environmental conditions such as pH, temperature, and nutrient availability to enhance large-scale biosorption processes, bridging gaps noted in previous literature regarding the scalability of bacterial biosorption. Additionally, the manuscript underscores the necessity for further research in biotechnology and molecular engineering to fully harness the potential of bacterial biosorption for chromium remediation, presenting a forward-looking perspective on advancing this bioremediation strategy. Full Abstract Chromium possesses detrimental effects on the health of both plants and animals. Biosorption is a process where biological materials (bacteria, fungi, algae, or agricultural waste) are used to remove pollutants from contaminated sites. Conventional methods of remediating heavy metal-contaminated soils, such as excavation and chemical treatment, are expensive and disruptive, making them less desirable. Factors influencing bacterial biosorption efficiency are promising approaches involving bacteria to remove heavy metals such as Chromium, lead, nickel, cadmium, arsenic, etc., from contaminated soil. Some bacterial genera involved in biosorption include Alcaligens, Achromobacter, Acinetobacter, Alteromonas, Arthrobacter, Burkholderia, Bacillus, Enterobacter, Flavobacterium, and Pseudomonas. These bacteria can adsorb heavy metals such as Chromium and biotransform them into less toxic forms. Some factors influencing bacteria biosorption efficiency include pH, temperature, concentration, bacterial surface compositions, metal ion characteristics, and soil composition. Challenges associated with using bacteria for biosorption, as outlined in previous literature, include the slowness of the process and the fact that it may not be suitable for large-scale application, even though many other authors have proven its applicability on a large scale. Also, the key quality needed from the bacterial biosorbent must be tolerating the heavy metals. Another area of focus in current research is optimizing environmental conditions, such as temperature, pH, and nutrient availability, to achieve a more efficient biosorption at a larger scale. This overview highlighted the roles of bacteria in the biosorption of chromium heavy metal as a strategy for the bioremediation of Chromium contaminated soil. Conclusively, bacterial biosorption has a great potential for use in Chromium- contaminated soil remediation, and more research is needed to fully realize this potential, especially in biotechnology and molecular engineering.

Isolation of Potential Azo dye Degrading/Tolerating Bacteria from Polluted Environment

Various industries including the food and textile industries result in the release of azo dyes into the environment. These dyes are known to exert toxic effects on humans, animal and plants. Biological methods of azo dye bioremediation is a solution for the detoxification of azo dye in the environment. The present study was undertaken to isolate bacteria with potential for azo dye bioremediation. From five polluted environment samples, eight bacteria were isolated in azo dye supplemented Nutrient agar. Six isolates (75%, n=8) decolorized azo dye completely following 24 hours of incubation. The control tube with no bacterial inoculation remained blue, indicating that only microbial biotransformation processes were taking place. In each case, a blue-colored ring remained at the top, indicating the anoxic nature of the dye decolorization process. All isolates grew in presence of 400 ppm, 60% tolerated 600 ppm and 20% tolerated 800 ppm, whereas 1000ppm was inhibitory for growth of all isolates. Dead autoclaved cells of three representative isolates were tested for biosorption potential. Only one isolate turned the methylene blue supplemented nutrient broth colorless. This explains that this isolate was not metabolizing methylene blue rather it bound the dye to the cell structure. Two isolates did not show biosorption abilities indicating that their mechanism of bioremediation was enzymatic reduction. 16s rDNA sequencing identified two of the isolates as Lysinibacillus capsici and Stenotrophomonas muris. Bangladesh J Microbiol, Volume 40, Number 2, December 2023, pp 56-59

Green Alternatives for Archaeological Iron Stabilization

ABSTRACT One of the most challenging types of artifact occurring within museum collections is unstable chloride-contaminated archaeological iron. A high chloride concentration causes cracking, flaking and leads to full mineralization, in effect making objects fragile. Consequently, removal of chloride ions plays a key role in stabilization treatment, while preserving the integrity of the corroded iron object. Despite the variety of stabilization methods, all have significant disadvantages, including a lack of sustainability. Within the framework of the Horizon Europe project GoGreen the potential of microbial biosorption to stabilize archaeological iron artefacts is being investigated. Dry biomass of the fungi Meyerozyma sp. and Saccharomyces cerevisiae was studied to remove chloride ions. Preliminary tests were carried out on artificially-aged steel samples. To assess the activities of the microorganisms’ functional groups and biosorption capabilities as a potential green stabilization treatment, analytical techniques including FTIR, Raman spectroscopy, and SEM-EDX were used. The results demonstrate two promising paths for the development of green stabilization treatments based on fungal biomass: passive adsorption into the cell wall and conversion of reactive corrosion products into more stable compounds. The use of microbial biomass opens up promising perspectives for the development of more sustainable solutions in archaeological iron stabilization, while avoiding the generation of toxic waste in our environment.

The valorization of Prunus mahaleb shell through acid modification for the sorption of Pb2+ removal from aqueous solution

AbstractThis study aimed to investigate the biosorption performance of acid-modified waste Prunus mahaleb (PMA) shells in the removal of Pb2+ ions from aqueous solutions. Changes in the morphological properties and functional components of PMA biosorbent were characterized using SEM–EDX, FT-IR, BET, and PZC analyses. The effect of various parameters such as initial Pb2+ concentration, pH, PMA dosage, contact time, and temperature on biosorption was investigated using a batch biosorption procedure. The maximum biosorption capacity, determined using the Langmuir isotherm, was calculated to be 119 mg g−1. It was found that the biosorption kinetic mechanism followed pseudo-second-order kinetics and intraparticle diffusion model. According to the determined thermodynamic parameters, the biosorption mechanism was found to be endothermic (ΔH° &gt; 0), spontaneous (ΔS° &gt; 0), and entropy-increasing (ΔG° &lt; 0). The outcomes of the experiment were evaluated in comparison to other sorbents that have been previously commonly used in the literature. It was demonstrated that PMA could be a promising, environmentally friendly, cost-effective, and sustainable potential biosorbent for the removal of Pb2+ ions.

A parametric optimization for leveraging the potential of ammonia modified magnetic pine cone hydrochar for Cr (VI) contaminated wastewater treatment

The present study evaluated the biosorption potential of magnetic pine cone hydrochar (MPHC) for chromium removal from wastewater. Initially, three different methodologies were followed for the synthesizing magnetic hydrochar and were tested for chromium removal and with a maximum removal of 91.3%, ammonia-modified MPHC showed its tremendous potential for Cr (VI) removal. Further, the hydrochar was characterized physically, chemically, magnetic, and morphological and a Box-Behnken experimental design was used for examining the effect of all the five parameters for Cr (VI) removal from the simulated wastewater system. Ammonia-modified MPHC showed a removal efficiency of 98.46% under the optimized batch shake flask system with the initial chromium concentration (55 mg/L), MPHC dose (550 mg/L), temperature (40 °C) and reaction time (120 min) and iron-MPHC ratio (30%). Here, the maximum Cr (VI) adsorption capability (qe) was found to be 154 mg/g. Further, the effect of different bed height, inlet pollutant flow rate, and inlet pollutant concentration during the continuous packed bed biosorption study showed a significant removal. The breakthrough curves for Cr (VI) removal obtained via the continuous flow-through column study confirmed that MPHC in the fixed-bed column suits Cr (VI) removal.