Plastiklerin ve Mikroplastiklerin Mikrobiyal Biyodegredasyonu: Enzimatik Mekanizmalar, Biyoteknolojik Uygulamalar ve Ekotoksikolojik Perspektifler

Öz

Plastik üretimindeki küresel artış, mikroplastik ve nanoplastiklerin çevresel olarak yoğun bir şekilde birikmesine ve parçalanmasına yol açmıştır. Bu kalıcı parçacıklar artık sucul, karasal ve atmosferik ekosistemlerde bulunmakta ve toksik kimyasalları taşıyarak, mikrobiyal toplulukları bozarak ve besin zincirine girerek ekotoksikolojik riskler oluşturmakta ve potansiyel insan sağlığı etkilerine neden olmaktadır. Bu nedenle, mikroorganizmalar tarafından biyolojik olarak parçalanma, sürdürülebilir bir iyileştirme stratejisi olarak dikkat çekmektedir. Bu derleme, mikroorganizmaların plastik ve mikroplastiklerin parçalanmasındaki rolünü inceleyerek enzimatik mekanizmalara, biyoteknolojik uygulamalara ve ilişkili risklere odaklanmaktadır. Ideonella sakaiensis, Pseudomonas, Bacillus ve Rhodococcus gibi bakteriler, genellikle biyofilm oluşumuyla güçlendirilen PETaz, MHETaz, kütinazlar ve oksidazlar aracılığıyla güçlü parçalanma yetenekleri sergilemektedir. Aspergillus ve Penicillium dahil olmak üzere mantarlar ve mikroalgler, hücre dışı enzimlerin üretimi ve sinerjik etkileşimler yoluyla katkıda bulunmaktadır. Sıcaklık, pH, tuzluluk ve oksijen seviyeleri gibi çevresel koşullar, mikrobiyal aktiviteyi ve enzim performansını doğrudan etkilemektedir. Biyoteknolojik yaklaşımlar, mikrobiyal konsorsiyumlar, genetik mühendisliği ve omik tabanlı yeni enzim keşfi yoluyla bozunma verimliliğini artırmaktadır. Biyoreaktörler ve nanopartikül destekli sistemler de dahil olmak üzere laboratuvar ölçekli uygulamalar, tek suşlara kıyasla daha yüksek bozunma oranlarına ulaşmaktadır. Ancak, doğal ortamlarda mikrobiyal stabilite, ölçeklenebilirlik ve tereftalat ve etilen glikol gibi bozunma ara maddelerinin toksisitesi gibi önemli sınırlamalar devam etmektedir. Genel olarak, mikrobiyal biyolojik bozunma, geleneksel işlemlere umut verici bir alternatif sunmakla birlikte, ekolojik güvenlik ve ekonomik fizibilite açısından dikkatli bir değerlendirme gerektirmektedir. Bu derleme, plastik biyolojik bozunmasını ilerletmek ve sürdürülebilir atık yönetimini desteklemek için mikrobiyoloji, biyoteknoloji ve çevresel toksikolojiyi birleştiren disiplinlerarası stratejilerin önemini vurgulamaktadır.

Anahtar Kelimeler

• Kütinaz
• PETaz
• Tereftalat
• Atık yönetimi

Microbial Biodegradation of Plastics and Microplastics: Enzymatic Mechanisms, Biotechnological Applications, and Ecotoxicological Perspectives

Abstract

The global rise in plastic production has resulted in extensive environmental accumulation and fragmentation into microplastics and nanoplastics. These persistent particles are now found in aquatic, terrestrial, and atmospheric ecosystems, posing ecotoxicological risks by transporting toxic chemicals, disrupting microbial communities, and entering the food chain, with potential human health impacts. Biodegradation by microorganisms has therefore gained attention as a sustainable remediation strategy. This review examines the role of microorganisms in degrading plastic and microplastics, focusing on enzymatic mechanisms, biotechnological applications, and associated risks. Bacteria such as Ideonella sakaiensis, Pseudomonas, Bacillus, and Rhodococcus exhibit strong degradative abilities via PETase, MHETase, cutinases, and oxidases, often enhanced by biofilm formation. Fungi, including Aspergillus and Penicillium, as well as microalgae, contribute through the production of extracellular enzymes and synergistic interactions. Environmental conditions—such as temperature, pH, salinity, and oxygen levels—directly influence microbial activity and enzyme performance. Biotechnological approaches have improved degradation efficiency through microbial consortia, genetic engineering, and omics-based discovery of novel enzymes. Laboratory-scale applications, including bioreactors and nanoparticle-assisted systems, have achieved higher degradation rates compared to single strains. However, major limitations persist, including microbial stability in natural environments, scalability, and the toxicity of degradation intermediates such as terephthalate and ethylene glycol. Overall, microbial biodegradation offers a promising alternative to conventional treatments but requires careful evaluation of ecological safety and economic feasibility. This review emphasizes the importance of interdisciplinary strategies combining microbiology, biotechnology, and environmental toxicology to advance plastic biodegradation and support sustainable waste management.

Keywords

• Cutinase
• PETase
• Terephthalate
• Waste management

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