Chromium (Cr)

Plant damage:

Hexavalent chromium is mobile, highly water soluble and easily penetrates cell membranes. These physical attributes result in its regular uptake by plants, wherein Cr(VI) exhibits high-toxicity behaviours.

  • Oxidative stress: Plants have a built-in antioxidant defence system which prevents damage by reactive oxygen species to cellular components, including lipids, proteins and DNA. This defence system carries an arsenal of counteractive measures including superoxide dismutase (SOD), catalase (CAT), peroxidases (POx), and non-enzymatic antioxidants such as ascorbate and glutathione. Chromium-induced stress impairs the activities of these enzymes, depletes the antioxidant pool and leads to oxidative stress.

  • Altered enzymatic activities: Cr(VI) directly interacts with plant proteins, leading to protein denaturation. Protein denaturation, simply put, involves breaking weak links or bonds within a protein molecule. These protein molecules are responsible for the strict ordering of protein structure that enables their function and operation, any damage to protein molecules will result in protein deformities that inhibit its operation. Cr(VI) ions bind to protein molecules disrupting their tertiary and quaternary structures, altering active site conformations necessary for enzyme catalysis and thereby activity. The excessive production of reactive oxygen species in the presence of Cr(VI) causes damage to enzymes either directly, by oxidising essential amino acid residues, or indirectly by initiating oxidative damage to an enzyme’s cofactors or similarly critical components. Cr(VI) can interfere with or disrupt enzyme regulatory mechanisms such as allosteric mechanisms, feedback inhibition, and post-translational modification. These interferences result in dysregulation and inhibition of enzyme activity.

  • Generation of ROS: Cr(VI) generates reactive oxygen species in plant cells. Within a plant cell, Cr(VI) will undergo redo reactions, forming distinctly reactive and damaging ROS including; superoxide radicals, hydroxyl radicals and hydrogen peroxide, all of which can cause damage to DNA resulting in apoptosis.

  • Inhibition of growth and biomass: Chromium is known to stunt the growth of contaminated plants. Chromium can frustrate nutrient uptake, prevent photosynthesis and obstruct hormone regulation. The impediment to these processes can limit cell division and elongation, resulting in shoot and root growth reductions. Chromium is capable of disturbing the absorption, translocation and assimilation of essential nutrients such as iron, manganese and calcium. Additionally, chromium can cause nutrient imbalances, deficiencies, or toxicities. Dysfunctional nutrient acquisition, unsurprisingly, interferes with plant growth and development.

  • Inhibition of photosynthetic activities: Photosystem II (PSII) is an essential component of photosynthetic machinery with responsibilities including, the initiation of the electron transport chain, as well as the capturing of light energy. Chromium damages reaction centre proteins, notably the D1 protein, required for electron transfer, thereby inhibiting PSII activity. These disruptions affect the conversion of light energy into chemical energy, significantly altering the photosynthetic process.

  • Inhibition of seed germination: Chromium in soil can disrupt metabolic processes that are critically involved in seed germination. These disruptions lead to poor or delayed rates of germination and ultimately reduce plant establishment and population density.

  • Altered Carbon Fixation: Chromium stress can lead to a decrease in carbon fixation rates in plants. Reduced photosynthetic efficiency, impaired enzyme activities (such as Rubisco, the key enzyme in carbon fixation), and disruption of CO2 diffusion processes contribute to decreased carbon assimilation. This reduction in carbon fixation limits the availability of carbohydrates for plant growth and development.

  1. Industrial Processes: Chromium is released into the environment through various industrial processes such as metal plating, electroplating, stainless steel production, leather tanning, and textile manufacturing.

  2. Mining and Ore Processing: Chromium mining and ore processing activities release chromium into the environment through excavation, crushing, and smelting processes.

  3. Waste Disposal: Improper disposal of chromium-containing waste materials, including industrial waste, electronic waste (e-waste), and construction waste, can result in the leaching of chromium into soil and groundwater.

  4. Coal Combustion: Chromium is naturally present in coal, and during the combustion of coal in power plants and other industrial facilities, it can be released into the atmosphere as fly ash or flue gas emissions.

  5. Cement Production: Cement manufacturing processes can involve the use of chromium-containing compounds as additives or in the kiln. This can lead to the release of chromium into the environment through cement dust or emissions.

  6. Tannery Operations: Chromium is commonly used in leather tanning processes to treat hides and make them more durable. Improper disposal of chromium-containing tanning waste can result in contamination of water bodies and soil.

  7. Wood Preservation: Chromium-based compounds, such as chromated copper arsenate (CCA), have been historically used as wood preservatives. Leaching of these compounds from treated wood can release chromium into the environment.

  8. Fossil Fuel Combustion: Chromium is present in trace amounts in fossil fuels, and its combustion in vehicles and industrial processes can contribute to chromium emissions.

  9. Industrial Accidents: Accidental spills, leaks, or releases during the transportation, storage, and handling of chromium-containing materials can lead to the direct discharge of chromium into the environment.

  10. Waste Incineration: The incineration of waste, including municipal solid waste and medical waste, can release chromium into the atmosphere through the combustion of chromium-containing materials.

  11. Electroplating and Metal Finishing: Electroplating and metal finishing operations, commonly found in the automotive, aerospace, and electronics industries, involve the use of chromium-based solutions. Improper waste management and disposal of these solutions can lead to the release of chromium into the environment.

  12. Chromium-Based Paints and Coatings: Certain paints and coatings contain chromium compounds for corrosion resistance and durability. Weathering, peeling, or scraping of these coatings can result in the release of chromium into the environment.

  13. Cooling Towers: Chromium-based corrosion inhibitors are sometimes used in cooling tower systems to prevent rust and scale formation. Leaching or disposal of cooling tower water can introduce chromium into water bodies.

  14. Pesticides and Biocides: Some pesticides and biocides contain chromium-based compounds. Agricultural practices involving the application of these compounds can result in the release of chromium into the soil and water through runoff and leaching.

  15. Domestic and Industrial Wastewater: Discharges from domestic and industrial wastewater, including households, manufacturing facilities, and wastewater treatment plants, can contain chromium if proper treatment measures are not in place.

Enzymes:

  • Chromium reductase enzyme

  • glutathione

  • Cr-chelating protein

  • extracellular polysaccharide-protein

  • metallothionein

  • metalloprotease

  • hydrolase

  • NADH dependant reductase

  • Oxidoreductase

The surface of the biosorbent/biomass has electron-donating agents including, hydroxyl groups, amine groups, and secondary alcohol groups. These functional groups interact positively with Cr(VI) in acidic conditions, resulting in hexavalent chromium’s reduction to tetravalent chromium, the non-soluble, less-toxic oxidative state of chromate. From there, Cr(III) binds to sulfonate or carboxyl groups, i.e. the negatively charged functional groups.

Where Cr(VI) binds to functional groups active on the fungal cell wall, their removal is carried out by ion exchange, complexation, chelation and surface precipitation processes.

Fungi %
 pH Time Biomass Type Removal Type Method Reference
A. Flavus Strain:
SFLStrain: A1120		 100
85		 5.1
5.1		 72hr
72hr		 living biomass
living biomass		 (m) bioaccumulation
(m) biosorption		 PDA solid medium & Liquid culture
PDA solid medium & Liquid culture		 S. Vajpai et al 2020S.
Vajpai et al 2020
Aspergillus foetidus 80 5 30min‡Œ
24hr		 Immobilised (m) extracellular sorption
(p) chemical sorption		 Batch sorption S. Ahluwalia & D. Goyal 2010
AspergillusĀ niger 79
96.3		 23 24hr
168hr		 living biomass
living biomass		 (m) adsorption
(m) biosorption		 Cellmass suspension
Batch biosorption		 N.Goyal et al 2003
D. Sivakumar 2016
Aspergillus orzae 97.6 5 30hr living biomass (m) biosorption Batch mode M. Sepehr et al 2005
Aspergillus terricola 79 4-5 immobilised (m) adsorption
(p) ion exchange		 Batch sorption S. Ahluwalia & D. Goyal 2010
Aspergillus terries 95mg/g 4.5 6days Immobilised (m) adsorption polyurethane foam units M.Dias et al 2001
Aspergillus terreus 100 6.5 96hr living biomass (m) bioaccumulation liquid medium A. Mishra & A. Malik 2014
Aspergillus tubingensis F12 64.5 5 5m/min immobilised (m) Leaching extracellular polymeric substance Tang et. al 2021
Aureobasidium pullulans 10 5 24hr immobilised (m) adsorption Batch sorption S. Ahluwalia & D. Goyal 2010
Aspergillus versicolor 99.89 6 7 days living biomass (m) bioaccumulation liquid molasses solution B. Tastan et al 2016
Candida utilis 81 6 1hr immobilised (m) biosorption biofilter S. Ali 2013
Cyberlindnera fabianii 100 48hr living biomass (m) adsorption
(p) reduction		 Aerobic batch W. Bahafid 2013
fusarium graminearum 100 7 12 days living (m) adsorption
(p) reduction
(p) accumulation		 Batch mode B. Shan et al 2019
Mucor hiemalis 99 5.7 48hr Living biomass (m) adsorption Multi-chamber batch Hoque & Fritscher 2019
Paecilomyces lilacinus 100 5.5-8 36hr -
120hr		 living biomass (m) reduction
(p) accumulation		 Growth media S. Sharma & A. Adholeya 2011
Paecilomyces variotii 90 5 24hr immobilised (m) adsorption
(p) ion exchange		 Batch sorption S. Ahluwalia & D. Goyal 2010
Penicillium chrysogenum 80 5 1.5hr immobilised (m) adsorption Hydrochloric acid pretreated X. Xu et al 2018
Penicillium Rubens 93.9 6 96hr living biomass (m) biosorption
(p) reduction		 Batch mode S. Yadav & A. Mishra 2022
Phanerochaete chrysosporium 98.43 2.32
2.55		 35days immobilised (m) adsorption
(p) precipitation
(p) dissolution		 soil remediation N. he et al
Rhizopus nigricans 75-78 2 8hr immobilised (m) adsorption polysulfone beads (multiple reuse) R. Bai & T. Abraham 2003

  • Ahluwalia, S.S. and Goyal, D. (2010). Removal of Cr(VI) from aqueous solution by fungal biomass. Engineering in Life Sciences, 10(5), pp.480–485. doi:https://doi.org/10.1002/elsc.200900111.

    Ali, S.A.A. (2013). Removal of Heavy Metals from Synthesis Industrial Wastewater Using Local Isolated Candida Utilis and Aspergillus Niger as Bio-Filter. The International Journal of Biotechnology, [online] 2(5), pp.83–90. Available at: https://archive.conscientiabeam.com/index.php/57/article/view/1499/2088.

    Goyal, N., Jain, S.C. and Banerjee, U.C. (2003). Comparative studies on the microbial adsorption of heavy metals. Advances in Environmental Research, 7(2), pp.311–319. doi:https://doi.org/10.1016/s1093-0191(02)00004-7.

    He, N., Hu, L., Jiang, C. and Li, M. (2022). Remediation of chromium, zinc, arsenic, Lead and Antimony Contaminated Acidic Mine Soil Based on Phanerochaete Chrysosporium Induced Phosphate Precipitation. Science of the Total Environment, [online] 850, p.157995. doi:https://doi.org/10.1016/j.scitotenv.2022.157995.

    M.A. Dias and others, Removal of heavy metals by an Aspergillus terreus strain immobilized in a polyurethane matrix, Letters in Applied Microbiology, Volume 34, Issue 1, 1 January 2002, Pages 46–50, https://doi.org/10.1046/j.1472-765x.2002.01040.x

    Mishra, A. and Malik, A. (2014). Novel fungal consortium for bioremediation of metals and dyes from mixed waste stream. Bioresource Technology, 171, pp.217–226. doi:https://doi.org/10.1016/j.biortech.2014.08.047.

    Shan, B., Hao, R.-X., Xu, H., Zhang, J., Li, J., Li, Y. and Ye, Y. (2022). Hexavalent Chromium Reduction and Bioremediation Potential of Fusarium Proliferatum S4 Isolated from chromium-contaminated Soil. Environmental Science and Pollution Research Volume, 29(52), pp.78292–78302. doi:https://doi.org/10.1007/s11356-022-21323-6.

    Sharma, S. and Adholeya, A. (2011). Detoxification and accumulation of chromium from tannery effluent and spent chrome effluent by Paecilomyces lilacinus fungi. International Biodeterioration & Biodegradation, 65(2), pp.309–317. doi:https://doi.org/10.1016/j.ibiod.2010.12.003.

    Sivakumar, D. (2016). Biosorption of hexavalent chromium in a tannery industry wastewater using fungi species. Global Journal of Environmental Science and Management, [online] 2(2), pp.105–124. doi:https://doi.org/10.7508/gjesm.2016.02.002.

    Taştan, B.E., Ertuğrul, S. and Dönmez, G. (2010). Effective bioremoval of reactive dye and heavy metals by Aspergillus versicolor. Bioresource Technology, [online] 101(3), pp.870–876. doi:https://doi.org/10.1016/j.biortech.2009.08.099.

    TY - JOUR AU - Yadav, Shweta AU - Mishra, Anand PY - 2022/03/20 SP - 233 EP - 239 T1 - Fungal biosorption of the heavy metals chromium(VI) and nickel from industrial effluent-contaminated soil VL - 14 DO - 10.31018/jans.v14i1.3297 JO - Journal of Applied and Natural Science ER -

    Vajpai S, Taylor PE, Adholeya A, Leigh Ackland M. Chromium tolerance and accumulation in Aspergillus flavus isolated from tannery effluent. J Basic Microbiol. 2020 Jan;60(1):58-71. doi: 10.1002/jobm.201900389. Epub 2019 Oct 16. PMID: 31617602.

    Xu, X., Zhang, Z., Huang, Q. and Chen, W. (2018). Biosorption Performance of Multimetal Resistant Fungus Penicillium chrysogenum XJ-1 for Removal of Cu2+ and Cr6+ from Aqueous Solutions. 35(1), pp.40–49. doi:https://doi.org/10.1080/01490451.2017.1310331.

Methods:

  • Adsorption

  • dissolution

  • reduction

  • ion exchange

  • Accumulation

  • Precipitation

  • Leaching

  • chemical sorption

  • extracellular reduction

Notes/ observations

There are three general stages involved in the removal of Cr(VI) by living biomass.

Binding: Binding of chromium ions to functional groups located on the cell’ surface

Translocation: transported proteins carry Cr(VI) through the cell membrane into the cell.

Reduction: Once inside the cell, Cr(VI) is reduced by chromate reducatse enzymes into Cr(III)

% = capacity of removal, (m) = most exhibited activity, (p) = partially exhibited activity

Types of application:

  • Living biomass

  • cell suspension

  • immobilised biomass

  • polyurethane foam

  • polyisoprene beads

  • calcium alginate beads

  • polyacrylamide and PVA beads

  • polysulfone beads

  • stacked biofilter

  • pretreated immobilised biomass

The vast collection of literature concerning the removal of chromium from contaminated soils and solutions has illustrated the physiochemical operations at play, paving the way for new researchers to make informed experimental selections involving the genomic/enzymatic profile of the fungal species, effective pre-treatment strategies, and methods of application to ensure stability, reuse and cost efficiency.

Another subdivision of bioremediation receiving only partial attention within these pages is phytoremediation, plant-based remediation. A number of plants with high metal tolerance are able to accumulate heavy metals such as chromium within their cell tissues without effecting too much damage to themselves, This accumulation results in the removal of chromium from the surrounding soil, thereby managing the fate of chromium in soil. While these studies have positively demonstrated the remediating abilities of plants, researchers are endeavouring to illustrate the combined effects of phyto and myco remediation strategies. These studies, employ the faculties of metal-tolerant, enzymatically prodigious Arbuscular mycorrhizal fungal as collaborators. These studies, though early in development, are proving to be substantially more effective in the task of heavy metal removal. Please refer to the bottom for links to case studies.  

Variables affecting efficiency:

  • pH

  • contact time

  • temperature

  • concentration of Cr

  • dosage of biomass

  • pretreatment

  • metal tolerance

Cell Wall Components:

  • β-1,3-D-glucan (encoded by genes FKS1 and FKS2)

  • β-1,6-glucan 

  • α-1,3-glucan (synthesised by α-glucan synthase (AGS1).

  • Melanin (1, 8-dihydroxynaphthalene (DHN) intermediate and from L-3, 4-dihydroxyphenylalanine (L-dopa)

  • chitin (synthesised from n-acetylglucosamine by the enzyme chitin synthase)

  • Mannan 

  • Glucuronoxylomannan (GXM)

  • phospholipids 

  • mannoproteins 

  • Chitosan 

Functional Groups:

  • Carboxyl

  • amine

  • phosphate

  • hydroxide

  • thiol

  • phosphate

  • carbonyl 

  • sulfonyl 

  • sulfonate

  • imidazole

  • imine

  • imidazole

  • phosphodiester

  • Aspergillus orzae

    Scientific name: Aspergillus oryzae

    Division: Ascomycota

    Family: Trichocomaceae

    Kingdom: Fungi

    Order: Eurotiales

    Aspergillus orzae

  • Aureobasidium pullulans

    Higher classification: Aureobasidium

    Division: Ascomycota

    Family: Dothioraceae

    Kingdom: Fungi

    Order: Dothideales

    Aureobasidium pullulans

  • Cladosporium resinae

    Kingdom: Fungi

    Division: Ascomycota

    Class: Incertae sedis

    Order: Incertae sedis

    Family: Amorphothecaceae

    Genus: Amorphotheca

    Species: A. resinae

    Cladosporium resinae

  • Trichoderma atrobrunneum

    Trichoderma atrobrunneum

  • Cyberlindnera fabianii

    Description goes here

  • Fusarium proliferatum

    Scientific name: Fusarium proliferatum

    Family: Nectriaceae

    Division: Ascomycota

    Kingdom: Fungi

    Order: Hypocreales

    Fusarium proliferatum

  • Fusarium Solani

    Class: Sordariomycetes

    Genus: Fusarium

    Order: Hypocreales

    Family: Nectriaceae

    Division: Ascomycota

    Kingdom: Fungi

    Fusarium Solani

  • Paecilomyces lilacinus

    Kingom: Fungi

    Phylum: Ascomycota

    Subdivision: Pezizomycotina

    Class: Eurotiomycetes

    Subclass: Eurotiomycetidae

    Order: Eurotiales

    Genus: Paecilomyces

    Paecilomyces lilacinus

  • Penicillium Rubens

    Kingdom: Fungi

    Division: Ascomycota

    Order: Eurotiales

    Family: Trichocomaceae

    Genus: Penicillium

    Species: P. rubens

    Penicillium Rubens

  • Paecilomyces variotii

    Kingdom: Fungi

    Division: Ascomycota

    Class: Eurotiomycetes

    Order: Eurotiales

    Family: Trichocomaceae

    Genus: Paecilomyces

    Species: P. variotii

    Paecilomyces variotii

  • Rhizopus nigricans

    Kingdom: Fungi

    Division: Mucoromycota

    Order: Mucorales

    Family: Mucoraceae

    Genus: Rhizopus

    Species: R. stolonifer

    Rhizopus nigricans

Abbreviations: Malondialdehyde—MDA; Superoxide dismutase—SOD; Catalase—CAT; Ascorbate peroxidase—APX; Peroxidase—POD; Guaiacol peroxidase—GPX; Hydrogen peroxide—H2O2. Sharma A et al 2020

  • Ali, S., Bharwana, S.A., Rizwan, M., Farid, M., Kanwal, S., Ali, Q., Ibrahim, M., Gill, R.A. and Khan, M.D. (2015). Fulvic acid mediates chromium (Cr) tolerance in wheat (Triticum aestivum L.) through lowering of Cr uptake and improved antioxidant defense system. Environmental Science and Pollution Research, 22(14), pp.10601–10609. doi:https://doi.org/10.1007/s11356-015-4271-7.

    Ameh, A.O., Muhammad, J.A. and Audu, H.G. (2013). Synthesis and characterization of antiseptic soap from neem oil and shea butter oil. African Journal of Biotechnology, [online] 12(29). doi:https://doi.org/10.4314/ajb.v12i29.

    Choudhary, S.P., Kanwar, M., Bhardwaj, R., Yu, J.-Q. and Tran, L.-S.P. (2012). Chromium Stress Mitigation by Polyamine-Brassinosteroid Application Involves Phytohormonal and Physiological Strategies in Raphanus sativus L. PLoS ONE, 7(3), p.e33210. doi:https://doi.org/10.1371/journal.pone.0033210.

    Ma, J., Chunfang Lv, Xu, M., Chen, G., Chuangen Lv and Gao, Z. (2015). Photosynthesis performance, antioxidant enzymes, and ultrastructural analyses of rice seedlings under chromium stress. 23(2), pp.1768–1778. doi:https://doi.org/10.1007/s11356-015-5439-x.

    Maiti, S., Ghosh, N., Mandal, C., Das, K., Dey, N. and Adak, M.K. (2012). Responses of the maize plant to chromium stress with reference to antioxidation activity. Brazilian Journal of Plant Physiology, 24(3), pp.203–212. doi:https://doi.org/10.1590/s1677-04202012000300007.

    Paiva, L.B., Correa, S.F., Santa Catarina, C., Floh, E.I.S., Silva, M.G. da and Vitória, A.P. (2014). Ecophysiological and Biochemical Parameters for Assessing Cr+6 Stress Conditions in Pterogyne Nitens Tul. : New and Usual Methods for the Management and Restoration of Degraded areas. www.repositorio.ufop.br. [online] Available at: https://www.repositorio.ufop.br/handle/123456789/8332

    Rahman, M.M., Rahman, M.M., Islam, K.S. and Chongling, Y., 2010. Effect of chromium stress on antioxidative enzymes and malondialdehyde content activities in leaves and roots of mangrove seedlings Kandelia candel (L.) Druce. Journal of forest and environmental science, 26(3), pp.171-179.

    Rai, V., Vajpayee, P., Singh, S.N. and Mehrotra, S. (2004). Effect of Chromium Accumulation on Photosynthetic pigments, Oxidative Stress Defense system, Nitrate reduction, Proline Level and Eugenol Content of Ocimum Tenuiflorum L. Plant Science, 167(5), pp.1159–1169. doi:https://doi.org/10.1016/j.plantsci.2004.06.016.

    SHANKER, A., DJANAGUIRAMAN, M., SUDHAGAR, R., CHANDRASHEKAR, C. and PATHMANABHAN, G. (2004). Differential antioxidative response of ascorbate glutathione pathway enzymes and metabolites to chromium speciation stress in green gram ( (L.) R.Wilczek. cv CO 4) roots. Plant Science, 166(4), pp.1035–1043. doi:https://doi.org/10.1016/j.plantsci.2003.12.015.

    Surekha (2012). Chromium Stress on peroxidase, Ascorbate Peroxidase and Acid Invertase in Pea (Pisum Sativum L.) Seedling. International Journal for Biotechnology and Molecular Biology Research, 3(2). doi:https://doi.org/10.5897/ijbmbr11.052.

    Trinh, N.-N., Huang, T.-L., Chi, W.-C., Fu, S.-F., Chen, C.-C. and Huang, H.-J. (2013). Chromium Stress Response Effect on Signal Transduction and Expression of Signaling Genes in Rice. Physiologia Plantarum, 150(2), pp.205–224. doi:https://doi.org/10.1111/ppl.12088.

    Xu, L., Han, L. and Huang, B. (2011). Membrane Fatty Acid Composition and Saturation Levels Associated with Leaf Dehydration Tolerance and Post-Drought Rehydration in Kentucky Bluegrass. Crop Science, 51(1), pp.273–281. doi:https://doi.org/10.2135/cropsci2010.06.0368.

    Zhang, X., Zhang, S., Xu, X., Li, T., Gong, G., Jia, Y., Li, Y. and Deng, L. (2010). Tolerance and accumulation characteristics of cadmium in Amaranthus hybridus L. 180(1-3), pp.303–308. doi:https://doi.org/10.1016/j.jhazmat.2010.04.031.

How Chromium affects soil microorganisms:

  1. Toxicity: High concentrations of chromium, particularly in its hexavalent form (Cr(VI)), can be toxic to soil microorganisms. Chromium toxicity can disrupt microbial cell membranes, enzymes, and DNA, leading to reduced microbial activity, growth inhibition, and even cell death.

  2. Changes in Microbial Community Structure: Chromium contamination can alter the composition and diversity of soil microbial communities. Certain microbial groups may be more sensitive to chromium, leading to a decrease in their abundance. This can disrupt the balance of microbial populations and affect soil ecosystem functions.

  3. Impaired Microbial Metabolism: Chromium can interfere with microbial metabolic processes. It can inhibit enzyme activities involved in nutrient cycling, organic matter decomposition, and other crucial microbial-mediated transformations in the soil. This disruption can impact nutrient availability, organic matter breakdown, and overall soil fertility.

  4. Reduced Nutrient Cycling: Soil microorganisms play a vital role in nutrient cycling by decomposing organic matter, mineralizing nutrients, and participating in nutrient transformations. Chromium toxicity can impede these processes, leading to decreased nutrient cycling efficiency and nutrient availability for plants.

  5. Disruption of Symbiotic Relationships: Chromium contamination can affect symbiotic relationships between microorganisms and plants. For example, arbuscular mycorrhizal fungi, which form beneficial associations with plant roots, may be negatively impacted by chromium. This can reduce nutrient uptake efficiency and compromise plant-microbe interactions.

  6. Production of Reactive Oxygen Species (ROS): Chromium-induced oxidative stress can lead to the generation of reactive oxygen species (ROS) in soil. ROS can damage microbial cells, enzymes, and genetic material, impairing microbial function and survival.

  7. Altered Soil Enzyme Activities: Soil enzymes produced by microorganisms are essential for organic matter decomposition, nutrient cycling, and various biochemical reactions. Chromium can inhibit soil enzyme activities, including cellulases, proteases, and dehydrogenases, thereby disrupting the decomposition and nutrient cycling processes.

  8. Shifts in Microbial Functions: Chromium contamination can cause shifts in microbial community functions. Certain chromium-tolerant microbial species or strains may dominate under chromium-stressed conditions, potentially altering the functional capacities of the microbial community.

  • Ertani, A., Mietto, A., Borin, M. and Nardi, S. (2017). Chromium in Agricultural Soils and Crops: a Review. Water, Air, & Soil Pollution, 228(5). doi:https://doi.org/10.1007/s11270-017-3356-y.

    HUANG, S., PENG, B., YANG, Z., CHAI, L. and ZHOU, L. (2009). Chromium accumulation, Microorganism Population and Enzyme Activities in Soils around chromium-containing Slag Heap of Steel Alloy Factory. Transactions of Nonferrous Metals Society of China, 19(1), pp.241–248. doi:https://doi.org/10.1016/s1003-6326(08)60259-9.

    L, D.M., Rajendiran, S., D, M.V., K, S.J., Vassanda, C.M., Kundu, S. and K, P.A. (2017). Influence of Chromium Contamination on Carbon Mineralization and Enzymatic Activities in Vertisol. Agricultural Research, [online] 6(1), pp.91–96. doi:https://doi.org/10.1007/s4000301602426.

    Ross, D., Sjogren, R.E. and Bartlett, R.H. (1981). Behavior of Chromium in Soils: IV. Toxicity to Microorganisms. 10(2), pp.145–148. doi:https://doi.org/10.2134/jeq1981.00472425001000020004x.

    Viti, C. and Giovannetti, L., 2001. The impact of chromium contamination on soil heterotrophic and photosynthetic microorganisms. Annals of microbiology, 51(2), pp.201-214.

    Viti, C. and Giovannetti, L. (2014). The Impact of Chromium Contamination on Soil Heterotrophic and Photosynthetic Microorganisms BIOHYPO (Confronting the Clinical Relevance of Biocide Induced Antibiotic resistance) View Project Bacterial Symbioses in the Olive Fruit Fly View Project.

    Wyszkowska, J., Kucharski, J., Jastrzębska, E. and Hlasko, A. (2001). The Biological Properties of Soil as Influenced by Chromium Contamination. Polish Journal of Environmental Studies, 10(1), pp.37–42.

    Zhu, Y., Song, K., Cheng, G., Xu, H., Wang, X., Qi, C., Zhang, P., Liu, Y. and Liu, J. (2023). Changes in the bacterial communities in chromium-contaminated soils. Frontiers in Veterinary Science, [online] 9. doi:https://doi.org/10.3389/fvets.2022.1066048.

  1. DNA Damage: Chromium can enter cells whereupon its reduction to Cr(V), Cr(IV), Cr(III), and reactive oxygen species is facilitated by enzymatic activities. These reductions lead to several notable damages to DNA including, base modification, single and double-strand breaks, and Cr-DNA or protein adducts.

  2. Formation of DNA Adducts: Chromium can form covalent bonds with DNA, resulting in the formation of DNA adducts. Cr(VI) can bind to DNA bases, particularly guanine, forming stable adducts. These adducts can disrupt the normal structure and function of DNA, potentially interfering with DNA replication, transcription, and repair processes.

  3. Inhibition of DNA Repair: Chromium exposure can inhibit DNA repair mechanisms in cells. The DNA repair machinery, which is responsible for detecting and correcting DNA damage, may be impaired by chromium-induced oxidative stress or direct interference with DNA repair enzymes. This can lead to the accumulation of DNA lesions and compromised genome integrity.

  4. Genomic Instability: Chromium-induced DNA damage and impaired DNA repair can contribute to genomic instability, which refers to an increased propensity for genetic alterations and mutations. Genomic instability can lead to the accumulation of DNA mutations and chromosomal aberrations, increasing the risk of genetic diseases, cancer development, and other adverse health effects.

  5. Epigenetic Modifications: Chromium exposure can influence epigenetic modifications, which are heritable changes in gene expression that do not involve alterations in the DNA sequence. Chromium can affect DNA methylation patterns and histone modifications, potentially leading to changes in gene expression profiles and cellular function.

  6. Altered Gene Expression: Chromium exposure can modulate gene expression patterns through various mechanisms, including direct interaction with transcription factors or chromatin remodelling proteins. Changes in gene expression can disrupt normal cellular processes and contribute to cellular dysfunction or disease development.

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    TY - JOUR AU - Hossain, Mohammad AU - HASAN, ZUBAIR PY - 2014/08/31 SP - 1 EP - 10 T1 - EXCESS AMOUNT OF CHROMIUM TRANSPORT FROM TANNERY TO HUMAN BODY THROUGH POULTRY FEED IN BANGLADESH AND ITS CARCINOGENIC EFFECTS VL - 4 JO - International Journal of Civil, Structural, Environmental and Infrastructure Engineering Research and Development (IJCSEIERD) ER -

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