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Günümüzde ağır metal kirliliği önemli çevre sorunlarından biri haline gelmiştir. Kadmiyum, kurşun ve krom gibi ağır metallerin düşük konsantrasyonları canlılar için toksiktir. Krom (Cr), dünyadaki en toksik ağır metallerden biridir ve endüstriyel olarak salınan yaygın bir çevresel kirleticilerdendir. Cr metal iyonu; biyolojik olarak parçalanmayan ve doğada biriken bir ağır metaldir. Krom, biyolojik olarak gerekli değildir ve alıcı ortamlara (su ve toprak gibi) yapılan deşarjlar sonucunda besin zinciri boyunca birikerek insanlara kadar aktarılır. Kromun ana kaynakları; tabakhaneler, elektrokaplama, madencilik, tekstil, metal işleme, gübre, boyalar ve pigment imalat sanayi gibi çeşitli endüstrilerdir. İnsan sağlığı ve su ekosistemleri üzerinde olumsuz etkileri olan krom metal iyonları, farklı arıtma teknolojileri ile su ve atık sudan uzaklaştırılmalıdır. Krom giderimin de yaygın kullanılan metotlar; ters osmoz, elektrokimyasal prosesler, iyon değişimi, aktif karbona adsorpsiyon ve katılaştırma/stabilizasyondur. Bu yöntemlerin pahalı olmaları, yan ürün oluşumu ve çevre dostu olmamaları gibi bazı dezavantajları vardır. Biyoremediasyon prosesleri ise tüm bu sorunlara bir çözüm getirmiş ve çevre, ekonomi ve enerji açısından fayda sağlamıştır. Bakterilerin ağır metallere karşı geliştirdikleri direnç mekanizmaları sayesinde, ağır metallerin yüksek derişimlerinin olduğu ortamlarda hayatta kalırlar. Bakterilerin krom metal iyonunu bağlama kapasitelerini artırmak için biyoremediasyon umut verici bir prosestir. Yabanıl bakterilere, metalotiyonein, poli-histidinler veya poli-sisteinler gibi peptidler eksprese edilerek metal bağlama kapasitesini artırılabilmektedir. Bu derlemede; hücre içine metal girişinin engellenmesi, metalin proteinlere bağlanarak hücre içinde tutulması, metallerin hücrenin dışında tutulması, enzimlerle metalin daha az toksik forma dönüştürülmesi gibi direnç mekanizmalarına yer verilmiştir. Bu çalışmada, bazı yabanıl ve rekombinant bakteri türlerinin krom metal iyonunu giderimleri araştırılmıştır. Bu derlemenin amacı kromu etkili bir şekilde bağlayan bakterileri ve proteinleri özetlemektir.
Today, heavy metal pollution has become one of the major environmental problems. Low concentrations of heavy metals such as cadmium, bullet and chromium are toxic to animals. Chromium (Cr) is one of the most toxic heavy metals in the world and is one of the widespread environmental pollutants that are industrially released. Cr metal ion is a heavy metal that is not biodegraded and accumulated in nature. Chromium is not biologically necessary and is transferred to humans as a result of discharges to the receptor environments (such as water and soil) and accumulated throughout the nutritional chain. The main sources of chromium are various industries such as layers, electro-covering, mining, textile, metal processing, fertilizer, painting and pigment manufacturing. Chromium metal ions, which have adverse effects on human health and water ecosystems, should be removed from water and waste water with different processing technologies. The methods of chrom removal are also commonly used: reverse osmosis, electrochemical processes, ion change, active carbon adsorption and rigidity/stabilization. These methods have some disadvantages, such as being expensive, the formation of side products and not environmentally friendly. The non-mediation processes have brought a solution to all these problems and have provided benefits in terms of environmental, economic and energy. Thanks to the resistance mechanisms that bacteria develop against heavy metals, they survive in environments where heavy metals have a high skin. Mediation is a hopeful processist to increase bacteria’s capacity to connect the chromium metal ion. Peptides such as wild bacteria, metalotionein, poly-histidines or poly-cysteins can be expressed to increase the metal bonding capacity. In this collection, it is included in resistance mechanisms such as blocking the entrance of metal into the cell, holding the metal inside the cell by connecting to the proteins, holding the metals outside the cell, enzymes converting the metal into less toxic form. In this study, some wild and recombinant bacteria types of chromium metal ions are studied. The purpose of this aggregation is to summarize the bacteria and proteins that effectively bind chromium.
Today, heavy metal pollution has become one of the most important environmental problems. Low concentrations of heavy metals such as cadmium, lead and chromium are toxic to living things. Chromium (Cr) is one of the most toxic heavy metals in the world and is a common industrially released environmental pollutant. Chromium is a heavy metal that is non-biodegradable and accumulated in nature. For this reason, it is very important to treat chromium metal ion by making it suitable for discharge limits. Chromium is not biologically necessary and accumulates along the food chain as a result of discharges to receiving environments (such as water and soil) and transferred to humans. The main sources of chromium are various industries such as tanneries, electroplating, mining, textile, metal processing, fertilizer, dyes and pigment manufacturing industry. Chromium metal ions, which has negative effects on human health and water ecosystems, should be removed from water and wastewater with different treatment technologies. The most widely used methods are for chromium removal conventional physicochemical processes such as reverse osmosis, electrochemical process, ion exchange, adsorption on activated carbon, and solidification/stabilization, etc. These disadvantages, such as being expensive, waste product formation and being not environmentally friendly, limit their use. Bioremediation processes have brought a solution to all these problems and have benefited in terms of environment, economy and energy. Thanks to the resistance mechanisms developed by bacterias against heavy metals, they survive in environments with high concentrations of heavy metals. Bioremediation is a promising process to increase the capacity of bacteria to bind chromium metal ion. In this review; Resistance mechanisms such as preventing the entry of metal into the cell, keeping the metal in the cell by binding to proteins, keeping the metals out of the cell, and turning the metal into less toxic form with enzymes are included. In this study, the efficiencies of some wild and recombinant bacterial species on the removal of chromium will be investigated. The purpose of this review is to summarize bacteria and proteins that bind chromium metal ions effectively.
Alan : Fen Bilimleri ve Matematik; Mühendislik
Dergi Türü : Uluslararası
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