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Baysal A, Saygin H, Soyocak A. A Comparative Study on the Interaction Between Protein and PET Micro/Nanoplastics: Structural and Surface Characteristics of Particles and Impacts on Lung Carcinoma Cells (A549) and Staphylococcus aureus. ENVIRONMENTAL TOXICOLOGY 2024. [PMID: 38923375 DOI: 10.1002/tox.24366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 04/24/2024] [Accepted: 05/23/2024] [Indexed: 06/28/2024]
Abstract
The interaction between particles and proteins is a key factor determining the toxicity responses of particles. Therefore, this study aimed to examine the interaction between the emerging pollutant polyethylene terephthalate micro/nanoplastics from water bottles with bovine serum albumin. The physicochemical characteristics of micro/nanoplastics were investigated using nuclear magnetic resonance, x-ray diffraction, Fourier transform infrared, dynamic light scattering, and x-ray energy dispersive spectroscopy after exposure to various concentrations and durations of protein. Furthermore, the impact of protein-treated micro/nanoplastics on biological activities was examined using the mitochondrial activity and membrane integrity of A549 cells and the activity and biofilm production of Staphylococcus aureus. The structural characteristics of micro/nanoplastics revealed an interaction with protein. For instance, the assignment of protein-related new proton signals (e.g., CH2, methylene protons of CH2O), changes in available protons s (e.g., CH and CH3), crystallinity, functional groups, elemental ratios, zeta potentials (-11.3 ± 1.3 to -12.4 ± 1.7 to 25.5 ± 2.3 mV), and particle size (395 ± 76 to 496 ± 60 to 866 ± 82 nm) of micro/nanoplastics were significantly observed after protein treatment. In addition, the loading (0.012-0.027 mM) and releasing (0.008-0.013 mM) of protein also showed similar responses with structural characteristics. Moreover, the cell-based responses were changed regarding the structural and surface characteristics of micro/nanoplastics and the loading efficiencies of protein. For example, insignificant mitochondrial activity (2%-10%) and significant membrane integrity (12%-28%) of A549 cells increased compared with control, and reductions in bacterial activity (5%-40%) in many cases and biofilm production specifically at low dose of all treatment stages (13%-46% reduction) were observed.
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Affiliation(s)
- Asli Baysal
- Department of Chemistry, Faculty of Science and Letters, Istanbul Technical University, Istanbul, Turkey
| | - Hasan Saygin
- Application and Research Center for Advanced Studies, Istanbul Aydin University, Istanbul, Turkey
| | - Ahu Soyocak
- Department of Medical Biology, Faculty of Medicine, Istanbul Aydin University, Istanbul, Turkey
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2
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Sharma V, Singh P, Trivedi B, Kamboj N, Bisht A, Pandey N. Assessment of Iron Biosorption Potential by Live and Dead Biomass of Bacillus subtilis (MN093305) from Aqueous Solution. Indian J Microbiol 2024; 64:153-164. [PMID: 38468736 PMCID: PMC10924875 DOI: 10.1007/s12088-023-01144-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 11/13/2023] [Indexed: 03/13/2024] Open
Abstract
Heavy metals polluted aquatic ecosystems and become a global environmental issue due to their toxic effect on all forms of ecosystems and further on all forms of life. Heavy metals are non- degradable and accumulated in different life forms by accumulating in the food chain; this increases the need for the development of a sustainable method for the removal of these metals. Biosorption is an eco-friendly and cost-effective convenient technique of heavy metal bioremediation from the contaminated aquatic ecosystem. The current investigation involves biosorption of iron using Bacillus subtilis strain (MN093305) isolated from Ganga river at different physical parameters with the highest rate of biosorption was 96.64%, 98.91%, 97.88%, and 99.44% at pH 5, 60 min incubation period, 35 °C temperature and 2.5 mg/ml of biomass respectively for dead biomass. Living biomass biosorption rate was 87.32%, 96.74%, 96.94% and 95.02% at pH 7, 72 h, 35 °C and 2.5 mg/ml respectively. Functional groups involved in the biosorption of iron by Bacillus subtilis were fitted to a second-order kinetic model. Langmuir and Freundlich's isotherm are used to evaluate data; both isotherms indicate iron absorption as a favorable process.
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Affiliation(s)
- Vani Sharma
- Department of Microbiology, Motherhood University, Roorkee, 247661 India
| | - Padma Singh
- Department of Microbiology, Kanya Gurukul Campus, Gurukul Kangri Vishwavidhyalaya, Haridwar, 249404 India
| | - Bhavya Trivedi
- Department of Microbiology, Maya Group of Colleges, Dehradun, 248011 India
| | - Nitin Kamboj
- Department of Zoology and Environmental Science, Gurukul Kangri Vishwavidhyalaya, Haridwa, 249404 India
| | - Aditi Bisht
- Department of Zoology and Environmental Science, Gurukul Kangri Vishwavidhyalaya, Haridwa, 249404 India
| | - Neeraj Pandey
- Department of Zoology and Environmental Science, Gurukul Kangri Vishwavidhyalaya, Haridwa, 249404 India
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Li X, Xiao Q, Shao Q, Li X, Kong J, Liu L, Zhao Z, Li R. Adsorption of Cd (II) by a novel living and non-living Cupriavidus necator GX_5: optimization, equilibrium and kinetic studies. BMC Chem 2023; 17:54. [PMID: 37316907 DOI: 10.1186/s13065-023-00977-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 05/30/2023] [Indexed: 06/16/2023] Open
Abstract
Biosorbents have been extensively studied for heavy metal adsorption due to their advantages of low cost and high efficiency. In the study, the living and non-living biomass of Cupriavidus necator GX_5 previously isolated were evaluated for their adsorption capacity and/or removal efficiency for Cd (II) through batch experiments, SEM and FT-IR investigations. The maximum removal efficiency rates for the live and dead biomass were 60.51% and 78.53%, respectively, at an optimum pH of 6, a dosage of 1 g/L and an initial Cd (II) concentration of 5 mg/L. The pseudo-second-order kinetic model was more suitable for fitting the experimental data, indicating that the rate-limiting step might be chemisorption. The Freundlich isotherm model fit better than the Langmuir isotherm model, implying that the adsorption process of both biosorbents was heterogeneous. FT-IR observation reflected that various functional groups were involved in Cd (II) adsorption: -OH, -NH, C=O, C-O and C-C groups for the living biomass and -OH, -NH, C-H, C = O, C-N and N-H groups for the dead biomass. Our results imply that non-living biosorbents have a higher capacity and stronger strength for absorbing Cd (II) than living biomass. Therefore, we suggest that dead GX_5 is a promising adsorbent and can be used in Cd (II)-contaminated environments.
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Affiliation(s)
- Xingjie Li
- College of Life Science and Environmental Resources, Yichun University, Yichun, 336000, China.
- Engineering Technology Research Center of Jiangxi Universities and Colleges for Selenium Agriculture, Yichun, 336000, China.
- Key Laboratory of Crop Growth and Development Regulation of Jiangxi Province, Yichun, 336000, China.
| | - Qiusheng Xiao
- College of Life Science and Environmental Resources, Yichun University, Yichun, 336000, China
- Engineering Technology Research Center of Jiangxi Universities and Colleges for Selenium Agriculture, Yichun, 336000, China
- Key Laboratory of Crop Growth and Development Regulation of Jiangxi Province, Yichun, 336000, China
| | - Qin Shao
- College of Life Science and Environmental Resources, Yichun University, Yichun, 336000, China
| | - Xiaopeng Li
- College of Life Science and Environmental Resources, Yichun University, Yichun, 336000, China
- Engineering Technology Research Center of Jiangxi Universities and Colleges for Selenium Agriculture, Yichun, 336000, China
| | - Jiejie Kong
- College of Life Science and Environmental Resources, Yichun University, Yichun, 336000, China
| | - Liyan Liu
- College of Life Science and Environmental Resources, Yichun University, Yichun, 336000, China
| | - Zhigang Zhao
- College of Life Science and Environmental Resources, Yichun University, Yichun, 336000, China
- Engineering Technology Research Center of Jiangxi Universities and Colleges for Selenium Agriculture, Yichun, 336000, China
| | - Rungen Li
- College of Life Science and Environmental Resources, Yichun University, Yichun, 336000, China
- Key Laboratory of Crop Growth and Development Regulation of Jiangxi Province, Yichun, 336000, China
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Mohamed MS, Hozayen WG, Alharbi RM, Ibraheem IBM. Adsorptive recovery of arsenic (III) ions from aqueous solutions using dried Chlamydomonas sp. Heliyon 2022; 8:e12398. [PMID: 36590564 PMCID: PMC9800544 DOI: 10.1016/j.heliyon.2022.e12398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/18/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
The present study aimed to descry the effectiveness of dried microalga Chlamydomonas sp. for disposing of arsenic from aqueous solution. The study included examining the impact of some factors on algae's adsorption capacity (optimization study), such as initial concentrations of heavy metal, biosorbent doses, pH and contact time. All trials have been performed at constant temperature 25 °C and shaking speed of 300 rpm. The optimization studying indicated the pH 4, contact time at 60 min, temperature 25 °C and biomass concentration of 0.6 g/l were the best optimum conditions for the bioremediation activity with maximum removal percentage 95.2% and biosorption capacity 53.8 mg/g. Attesting of biosorption by applying FTIR (Fourier transfigure infrared), XRD (X-ray diffraction), SEM-EDX (Scanning Electron Microscope - Energy Dispersive X-ray), DLS (Dynamic light scarring) and ZP (Zeta Potential) was conducted. Also, Kinetics, isotherm equilibrium and thermodynamics were carried out to explain the plausible maximum biosorption capacity and biosorption rate of biosorbent q maximum.
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Affiliation(s)
- Mostafa Sh. Mohamed
- Biochemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef 62511, Egypt
| | - Walaa G. Hozayen
- Biochemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef 62511, Egypt
| | - Reem Mohammed Alharbi
- Biology Department, Science College, University of Hafr Al Batin, Hafr Al Batin 39524, Saudi Arabia
| | - Ibraheem Borie M. Ibraheem
- Botany and Microbiology Department, Faculty of Science, Beni-Suef University, Beni-Suef, 62511, Egypt,Corresponding author.
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Khan M, Kamran M, Kadi RH, Hassan MM, Elhakem A, Sakit ALHaithloul HA, Soliman MH, Mumtaz MZ, Ashraf M, Shamim S. Harnessing the Potential of Bacillus altitudinis MT422188 for Copper Bioremediation. Front Microbiol 2022; 13:878000. [PMID: 35663894 PMCID: PMC9161743 DOI: 10.3389/fmicb.2022.878000] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/05/2022] [Indexed: 12/08/2022] Open
Abstract
The contamination of heavy metals is a cause of environmental concern across the globe, as their increasing levels can pose a significant risk to our natural ecosystems and public health. The present study was aimed to evaluate the ability of a copper (Cu)-resistant bacterium, characterized as Bacillus altitudinis MT422188, to remove Cu from contaminated industrial wastewater. Optimum growth was observed at 37°C, pH 7, and 1 mm phosphate, respectively. Effective concentration 50 (EC50), minimum inhibitory concentration (MIC), and cross-heavy metal resistance pattern were observed at 5.56 mm, 20 mm, and Ni > Zn > Cr > Pb > Ag > Hg, respectively. Biosorption of Cu by live and dead bacterial cells in its presence and inhibitors 1 and 2 (DNP and DCCD) was suggestive of an ATP-independent efflux system. B. altitudinis MT422188 was also able to remove 73 mg/l and 82 mg/l of Cu at 4th and 8th day intervals from wastewater, respectively. The presence of Cu resulted in increased GR (0.004 ± 0.002 Ug−1FW), SOD (0.160 ± 0.005 Ug−1FW), and POX (0.061 ± 0.004 Ug−1FW) activity. Positive motility (swimming, swarming, twitching) and chemotactic behavior demonstrated Cu as a chemoattractant for the cells. Metallothionein (MT) expression in the presence of Cu was also observed by SDS-PAGE. Adsorption isotherm and pseudo-kinetic-order studies suggested Cu biosorption to follow Freundlich isotherm as well as second-order kinetic model, respectively. Thermodynamic parameters such as Gibbs free energy (∆G°), change in enthalpy (∆H° = 10.431 kJ/mol), and entropy (∆S° = 0.0006 kJ/mol/K) depicted the biosorption process to a feasible, endothermic reaction. Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy-Dispersive X-Ray Spectroscopy (EDX) analyses revealed the physiochemical and morphological changes in the bacterial cell after biosorption, indicating interaction of Cu ions with its functional groups. Therefore, these features suggest the potentially effective role of B. altitudinis MT422188 in Cu bioremediation.
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Affiliation(s)
- Maryam Khan
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
| | - Muhammad Kamran
- School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, SA, Australia
| | - Roqayah H. Kadi
- Department of Biology, College of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Mohamed M. Hassan
- Department of Biology, College of Science, Taif University, Taif, Saudi Arabia
- *Correspondence: Mohamed M. Hassan,
| | - Abeer Elhakem
- Department of Biology, College of Sciences and Humanities, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
| | | | - Mona H. Soliman
- Botany and Microbiology Department, Faculty of Science, Cairo University, Giza, Egypt
- Biology Department, Faculty of Science, Taibah University, Al-Sharm, Yanbu El-Bahr, Saudi Arabia
| | - Muhammad Zahid Mumtaz
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
| | - Muhammad Ashraf
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
| | - Saba Shamim
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
- Saba Shamim,
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Chijioke Emmanuel C, O.J O, Ikemsinachi David O. Sorption studies of phthalic acid esters uptake from lagos lagoon sample using characterized gmelina arborea pericarp biosorbent. SEP SCI TECHNOL 2022. [DOI: 10.1080/01496395.2022.2036761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - Onipede O.J
- Department of Chemical and Food Sciences, Bells University of Technology, Ota, Nigeria
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7
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Shukla V, Runthala A, Rajput VS, Chandrasai PD, Tripathi A, Phulara SC. Computational and synthetic biology approaches for the biosynthesis of antiviral and anticancer terpenoids from Bacillus subtilis. Med Chem 2021; 18:307-322. [PMID: 34254925 DOI: 10.2174/1573406417666210712211557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 04/18/2021] [Accepted: 04/25/2021] [Indexed: 11/22/2022]
Abstract
Recent advancements in medicinal research have identified several antiviral and anticancer terpenoids that are usually deployed as a source of flavor, fragrances and pharmaceuticals. Under the current COVID-19 pandemic conditions, natural therapeutics with least side effects are the need of the hour to save the patients, especially, which are pre-affected with other medical complications. Although, plants are the major sources of terpenoids; however, for the environmental concerns, the global interest has shifted to the biocatalytic production of molecules from microbial sources. The gram-positive bacterium Bacillus subtilis is a suitable host in this regard due to its GRAS (generally regarded as safe) status, ease in genetic manipulations and wide industrial acceptability. The B. subtilis synthesizes its terpenoid molecules from 1-deoxy-d-xylulose-5-phosphate (DXP) pathway, a common route in almost all microbial strains. Here, we summarize the computational and synthetic biology approaches to improve the production of terpenoid-based therapeutics from B. subtilis by utilizing DXP pathway. We focus on the in-silico approaches for screening the functionally improved enzyme-variants of the two crucial enzymes namely, the DXP synthase (DXS) and farnesyl pyrophosphate synthase (FPPS). The approaches for engineering the active sites are subsequently explained. It will be helpful to construct the functionally improved enzymes for the high-yield production of terpenoid-based anticancer and antiviral metabolites, which would help to reduce the cost and improve the availability of such therapeutics for the humankind.
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Affiliation(s)
- Vibha Shukla
- Food, Drug and Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research, Vishvigyan Bhawan, 31 Mahatma Gandhi Marg, Lucknow-226001, India
| | - Ashish Runthala
- Department of Biotechnology, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur-522502, Andhra Pradesh, India
| | | | - Potla Durthi Chandrasai
- Department of Biotechnology, National Institute of Technology Warangal, Warangal-506004, Telangana, India
| | - Anurag Tripathi
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad- 201002, India
| | - Suresh Chandra Phulara
- Department of Biotechnology, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur-522502, Andhra Pradesh, India
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Shukla V, Phulara SC. Impact of culture condition modulation on the high-yield, high-specificity and cost-effective production of terpenoids from microbial sources: A review. Appl Environ Microbiol 2021; 87:AEM.02369-20. [PMID: 33257314 PMCID: PMC7851692 DOI: 10.1128/aem.02369-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent years have seen a remarkable increase in the non-natural production of terpenoids from microbial route. This is due to the advancements in synthetic biology tools and techniques, which have overcome the challenges associated with the non-native production of terpenoids from microbial hosts. Although, microbes in their native form have ability to grow in wide range of physicochemical parameters such as, pH, temperature, agitation, aeration etc; however, after genetic modifications, culture conditions need to be optimized in order to achieve improved titers of desired terpenoids from engineered microbes. The physicochemical parameters together with medium supplements, such as, inducer, carbon and nitrogen source, and cofactor supply not only play an important role in high-yield production of target terpenoids from engineered host, but also reduce the accumulation of undesired metabolites in fermentation medium, thus facilitate product recovery. Further, for the economic production of terpenoids, the biomass derived sugars can be utilized together with the optimized culture conditions. In the present mini-review, we have highlighted the impact of culture conditions modulation on the high-yield and high-specificity production of terpenoids from engineered microbes. Lastly, utilization of economic feedstock has also been discussed for the cost-effective and sustainable production of terpenoids.
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Affiliation(s)
- Vibha Shukla
- Food, Drug and Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research, Vishvigyan Bhawan, 31 Mahatma Gandhi Marg, Lucknow-226001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Suresh Chandra Phulara
- Department of Biotechnology, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur-522502, Andhra Pradesh, India
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Kalaycı Kara A, Fakıoğlu Ö, Kotan R, Atamanalp M, Alak G. The investigation of bioremediation potential of Bacillus subtilis and B. thuringiensis isolates under controlled conditions in freshwater. Arch Microbiol 2021; 203:2075-2085. [PMID: 33595691 DOI: 10.1007/s00203-021-02187-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/31/2020] [Accepted: 01/29/2021] [Indexed: 12/17/2022]
Abstract
Bioremediation is widely used to remove water pollution as environmentally friendly smart solutions. In this study, Bacillus isolates were investigated in terms of the effectiveness of single and multiple cultures in eliminating aquatic pollution related to aquaculture activities. In the established experimental setups, the environments where Bacillus isolates were inoculated with single and multiple cultures at 1 × 107 CFU/mL were evaluated comparatively with control groups without these isolates, and total aerobic mesophilic bacterial counts were performed in the petri dish by inoculation method. At the end of the 6 days of the experiment, in the environment in which single and multiple cultures of Bacillus isolates were presented with 17-20 ± 0.05 °C temperature and 5.1-8.1 pH 2-4.6 mg/l dissolved oxygen values (O2), 2% increase in total phosphorus (TP) value was observed. On the other hand, 4% removal of Ammonia-nitrogen (NH3-N), 80% removal of Nitrite-nitrogen (NO2-N), and 100% removal of Nitrate-nitrogen (NO3-N) were observed. In the changes in heavy metal concentrations, the removal of Ni, Cr, Se, Al, Cd, Mn, Fe, and B was observed from highest to lowest as 57%, 50%, 50%, 43%, 40%, 23%, 5%, and 2%, respectively. It also has been seen that B. thuringiensis isolate was observed to be more effective than B. subtilis in metal removal.
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Affiliation(s)
- Ayşe Kalaycı Kara
- Department of Seafood Processing, Faculty of Fisheries, Recep Tayyip Erdoğan University, 53040, Rize, Turkey
| | - Özden Fakıoğlu
- Department of Freshwater Biology, Faculty of Fisheries, Ataturk University, 25240, Erzurum, Turkey
| | - Recep Kotan
- Department of Plant Protection, Faculty of Agriculture, Ataturk University, 25240, Erzurum, Turkey
| | - Muhammed Atamanalp
- Department of Aquaculture, Faculty of Fisheries, Ataturk University, 25240, Erzurum, Turkey
| | - Gonca Alak
- Department of Aquaculture, Faculty of Fisheries, Ataturk University, 25240, Erzurum, Turkey.
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Rizvi A, Ahmed B, Zaidi A, Khan MS. Biosorption of heavy metals by dry biomass of metal tolerant bacterial biosorbents: an efficient metal clean-up strategy. ENVIRONMENTAL MONITORING AND ASSESSMENT 2020; 192:801. [PMID: 33263175 DOI: 10.1007/s10661-020-08758-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 11/16/2020] [Indexed: 05/22/2023]
Abstract
Heavy metals discharge at an unrestrained rate from various industries into the environment pose serious human health problems. Considering this, the present study aimed at exploring the metal biosorbing potentials of bacterial strains recovered from polluted soils. The bacterial strains (CPSB1, BM2 and CAZ3) belonging to genera Pseudomonas, Bacillus and Azotobacter expressing multi-metal tolerance ability were identified to species level as P. aeruginosa, B. subtilis and A. chroococcum, respectively, by 16S rRNA partial gene sequence analysis. The biosorption of cadmium, chromium, copper, nickel, lead and zinc by three dead bacterial genera were studied as a function of metal concentration, variable pH of the medium and reaction (contact) time. The three bacterial strains exhibited a tremendous metal removal ability which continued even at the highest tested concentration of some metals. Later, a decline in the percentage of biosorbed metals was recorded as the metal concentration was increased with the simultaneous generation of a driving force to overcome mass transfer resistance for movement of metal ions between the solution and the surface of adsorbent. Among test bacteria, B. subtilis biosorbed a maximum of 96% chromium at 25 μg mL-1 while the maximum percentage (91%) of biosorbed metals recorded at 400 μg Cd mL-1 was observed for P. aeruginosa. The sorption of metal ions by dead biomass of three bacterial genera at optimum conditions followed the order-(i) B. subtilis BM2: Pb > Cu > Ni > Cd > Cr, (ii) A. chroococcum CAZ3: Cr > Cd > Cu > Ni > Pb and (iii) P. aeruginosa CPSB1: Cd > Cr > Ni > Cu > Pb > Zn. It was found that the optimum pH for metal adsorption ranged between pH 8 and 9 which, however, declined substantially at pH 5.0 for all three bacterial strains. In general, the biosorption of Cd, Cr, Cu, Ni and Pb by B. subtilis and A. chroococcum and such metals along with Zn by P. aeruginosa occurred maximally up to 60 min of bacterial growth. The adsorption data with regard to five metals provide an outstanding fit to the Langmuir and Freundlich isotherms. The biosorptive ability of three bacterial genera correlated strongly (r2 > 0.9) with each metal. The bacteria belonging to two Gram-negative genera Pseudomonas (P. aeruginosa) and Azotobacter (A. chroococcum) and one Gram-positive genus Bacillus (B. subtilis) demonstrated exceptional metal removal efficiency and, hence, provides a comprehensive understanding of metal-bacteria sorption process which in effect paves the way for detoxifying/removing metals from contaminated environment.
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Affiliation(s)
- Asfa Rizvi
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, 202002, India.
| | - Bilal Ahmed
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, 202002, India
| | - Almas Zaidi
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, 202002, India
| | - Mohd Saghir Khan
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, 202002, India
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Abstract
Biosorption is a variant of sorption techniques in which the sorbent is a material of biological origin. This technique is considered to be low cost and environmentally friendly, and it can be used to remove pollutants from aqueous solutions. The objective of this review is to report on the most significant recent works and most recent advances that have occurred in the last couple of years (2019–2020) in the field of biosorption. Biosorption of metals and organic compounds (dyes, antibiotics and other emerging contaminants) is considered in this review. In addition, the use and possibilities of different forms of biomass (live or dead, modified or immobilized) are also considered.
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