Extremophiles and Their Application in Bioremediation

2022 ◽  
pp. 188-206
Author(s):  
Himanshu Pandey ◽  
Devendra Singh ◽  
Vinay Kumar Dhiman ◽  
Vivek Kumar Dhiman ◽  
Devendra Pandey

A microorganism dwelling in severe environmental conditions is termed an extremophile. These unfavorable environmental conditions include high salinity, toxin compounds, heavy metals, unfavorable temperature, and extremely acidic and alkaline pH. Microorganisms belonging to prokaryotes include true bacteria and archaea bacteria which prevail in harsh environments. In recent years, extremophilic, basically, archaea bacteria have been reported for their immense potential application in the bioremediation process. Bioremediation is a technique that utilizes microorganisms for the decomposition of organic and inorganic pollutants; anthropogenic activities are the basic cause of soil pollution, water pollution, and air pollution globally. Extremophiles are capable of producing enzymes that are thermolabile and can function normally even in extreme conditions. These enzymes and proteins can be utilized in the bioremediation process under extreme pH, heavy metal stress, and unfavorable temperature conditions. In this chapter, the role of extremophiles in bioremediation is discussed.

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Abolghassem Emamverdian ◽  
Yulong Ding ◽  
Yinfeng Xie ◽  
Sirous Sangari

The increased contaminants caused by anthropogenic activities in the environment and the importance of finding pathways to reduce pollution caused the silicon application to be considered an important detoxification agent. Silicon, as a beneficial element, plays an important role in amelioration of abiotic stress, such as an extreme dose of heavy metal in plants. There are several mechanisms involved in silicon mediation in plants, including the reduction of heavy metal uptake by plants, changing pH value, formation of Si heavy metals, and stimulation of enzyme activity, which can work by chemical and physical pathways. The aim of this paper is to investigate the major silicon-related mechanisms that reduce the toxicity of heavy metals in plants and then to assess the role of silicon in increasing the antioxidant enzyme and nonenzyme activities to protect the plant cell.


2019 ◽  
Vol 70 (17) ◽  
pp. 4477-4488 ◽  
Author(s):  
Laura C Terrón-Camero ◽  
M Ángeles Peláez-Vico ◽  
Coral Del-Val ◽  
Luisa M Sandalio ◽  
María C Romero-Puertas

Abstract Anthropogenic activities, such as industrial processes, mining, and agriculture, lead to an increase in heavy metal concentrations in soil, water, and air. Given their stability in the environment, heavy metals are difficult to eliminate and can constitute a human health risk by entering the food chain through uptake by crop plants. An excess of heavy metals is toxic for plants, which have various mechanisms to prevent their accumulation. However, once metals enter the plant, oxidative damage sometimes occurs, which can lead to plant death. Initial production of nitric oxide (NO), which may play a role in plant perception, signalling, and stress acclimation, has been shown to protect against heavy metals. Very little is known about NO-dependent mechanisms downstream from signalling pathways in plant responses to heavy metal stress. In this review, using bioinformatic techniques, we analyse studies of the involvement of NO in plant responses to heavy metal stress, its possible role as a cytoprotective molecule, and its relationship with reactive oxygen species. Some conclusions are drawn and future research perspectives are outlined to further elucidate the signalling mechanisms underlying the role of NO in plant responses to heavy metal stress.


2021 ◽  
Author(s):  
Narin Printarakul ◽  
Weeradej Meeinkuirt

Abstract Huay Pah Lahd stream in Doi Suthep-Pui National Park, Thailand, is potentially vulnerable to nearby anthropogenic activities. In this study, we determined heavy metal accumulation in bryophyte tissue and their growth substrates. Enrichment factors (EFs) of heavy metals were employed to monitor concentrations in bryophyte tissue. Of eight bryophyte taxa investigated, Scopelophila cataractae showed the highest capacity to accumulate metals in tissue, particularly Fe, Zn, Cd and Cu in protonemata (8,026.7, 1,187.2, 16.9 and 530.1 mg kg-1, respectively). Furthermore, the endangered and rare bryophyte taxa S. cataractae and Porella acutifolia were found intermingled with other urban and common aquatic bryophytes. These taxa might be considered sensitive warning organisms for heavy metal stress in stream ecosystems induced by environmental pollution. Because EFs of all heavy metals were < 2, this suggests that natural processes are the key source of heavy metals; furthermore, the environment of this National Park was identified as being heathy, and an important ecosystem buffer and biodiversity haven.


2021 ◽  
Vol 21 (No 1) ◽  
Author(s):  
Aaliya Ashraf ◽  
Savita Bhardwaj ◽  
Hammad Ishtiaq ◽  
Yendrembam K. Devi ◽  
Dhriti Kapoor

The issues of heavy metal adulteration are becoming common in world. Heavy metal toxicity cases are prevailing in mining industries, smelters, power plants based on coal burning, agriculture, etc. There are several heavy metals, such as Cd, Cu, Pb, Cr, Hg, Ar, etc. These heavy metals are major pollutants of environment, particularly in areas with increasing anthropogenic activities. The cumulation of heavy metal in soils is of great concern in agriculture because of the deleterious effects on food safety, crop growth and soil organisms’ health. Heavy metals affect several physiological and biochemical processes in plants. They diminish crop yield by bringing toxic effects to several physiological processes in plants such as, seed chlorophyll reduced by the production of reactive oxygen species, affecting the redox balance and instigating oxidative stress. Lead (Pb) is one of the looming heavy metal which is neither essential nor plays any part in the course of cell metabolism. Pb has toxic effects on plant which may include inhibition of photosynthesis, disruption of mineral nutrition and water balance, and disturbs membrane structure and permeability. Its phytotoxicity can also affect human health and can prove detrimental through food chain. However, in order to combat the effects generated by heavy metal stress particularly by Pb, several amelioratives can be used. Pb phytotoxicity can be ameliorated by the application of certain phytohormones which can be a part of signal transduction pathway, or they may trigger reactions and causative agents to respond to stress. Various signaling molecules such as NO, H2 S, CO, etc. enhance the activity of antioxidant enzymes, level of secondary metabolites and osmolytes, hence scavenge the oxidative stress due to generation of free radicals in response to heavy metal stress


This chapter highlights the role of cascade for remediation of heavy metals, their mechanism of action, and their applications approach of hyperaccumulation. Further, it also highlights the role of uptake and detoxification of metals by cellular mechanisms that facilitate the bioremediation of heavy metals from contaminated areas.


Author(s):  
Sangeetha Annam ◽  
Anshu Singla

Abstract: Soil is a major and important natural resource, which not only supports human life but also furnish commodities for ecological and economic growth. Ecological risk has posed a serious threat to the ecosystem by the degradation of soil. The high-stress level of heavy metals like chromium, copper, cadmium, etc. produce ecological risks which include: decrease in the fertility of the soil; reduction in crop yield & degradation of metabolism of living beings, and hence ecological health. The ecological risk associated, demands the assessment of heavy metal stress levels in soils. As the rate of stress level of heavy metals is exponentially increasing in recent times, it is apparent to assess or predict heavy metal contamination in soil. The assessment will help the concerned authorities to take corrective as well as preventive measures to enhance the ecological and hence economic growth. This study reviews the efficient assessment models to predict soil heavy metal contamination.


Cosmetics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 78
Author(s):  
Claire Tubia ◽  
Alfonso Fernández-Botello ◽  
Jan Dupont ◽  
Eni Gómez ◽  
Jérôme Desroches ◽  
...  

As an external appendage, hair is exposed to multiple stresses of different origins such as particles and gases in air, or heavy metals and chemicals in water. So far, little research has addressed the impact of water pollution on hair. The present study describes a new ex vivo model that allowed us to document the adverse effects of water pollutants on the structure of hair proteins, as well as the protective potential of active cosmetic ingredients derived from a biomimetic exopolysaccharide (EPS). The impact of water pollution was evaluated on hair from a Caucasian donor repeatedly immersed in heavy metal-containing water. Heavy metal retention in and on hair was then quantified using Inductively Coupled Plasma Spectrometry (ICP/MS). The adverse effects of heavy metals on the internal structure of hair and its prevention by the EPS were assessed through measurement of keratin birefringence. Notably, the method allows the monitoring of the organization of keratin fibers and therefore the initial change on it in order to modulate the global damage in the hair. Results revealed an increasing amount of lead, cadmium and copper, following multiple exposures to polluted water. In parallel, the structure of keratin was also altered with exposures. However, heavy metal-induced keratin fiber damage could be prevented in the presence of the tested EPS, avoiding more drastic hair problems, such as lack of shine, or decrease in strength, due to damage accumulation.


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