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Bioremediation of Polycyclic Aromatic Hydrocarbons (PAHs): An Overview
Published in M.H. Fulekar, Bhawana Pathak, Bioremediation Technology, 2020
However, for non-ligninolytic fungi, CYT P450 may also oxidize numerous PAH compounds into phenols (Pothuluri et al., 1996). Woody components containing a high-lignin content are mainly fragmented by extracellular enzymes produced by ligninolytic fungi/white rot fungi; similarly, PAHs may be oxidized by ligninolytic fungi to generate transient PAH diphenols and oxidized into quinones. PAH compounds are oxidized by lignin peroxidase in the presence of H2O2 and manganese peroxidase through Mn-dependent peroxidation (Liado et al., 2013). Lignin is a polymer with phenylpropane subunits that include linkages such as aryl ether and carbon-carbon bonds, which resemble with PAH compounds. Thus, ligninolytic fungi have been perceived as imminent PAH-degrading organisms. The ability of lignin-degrading fungi to break down PAH compounds depends on the production of multiple enzymatic systems such as lignin-peroxidase, manganese peroxidase, and laccase (Sevcan et al., 2017).
A Sustainable Approach to the Degradation and Detoxification of Textile Industry Wastewater for Environmental Safety
Published in Ram Naresh Bharagava, Sandhya Mishra, Ganesh Dattatraya Saratale, Rijuta Ganesh Saratale, Luiz Fernando Romanholo Ferreira, Bioremediation, 2022
Roop Kishor, Arpita Singh, Nandkishor More, Ram Naresh Bharagava
Several fungal/yeast species are well reported for the degradation of TIWW, as shown in Table 11.3. Different fungal species produce degradative enzymes, which degrade and decolourize textile dyes present in industrial wastewater (Sen et al., 2016; Haq et al., 2018). Degradative enzymes such as lignin peroxidase (LiP), manganese peroxidase (MnP) azoreductase and laccase catalyse or convert recalcitrant pollutants into non-toxic and mineralized compounds (Sen et al., 2016; Kishor et al., 2021a). For example, the Aspergillus strain has capabilities to degrade acid blue, Disperse Red 1 and Congo red dyes (Ameen et al., 2021).
Impact of Enzymes Based Treatment Methods on Biodegradation of Solid Wastes for Sustainable Environment
Published in Gunjan Mukherjee, Sunny Dhiman, Waste Management, 2023
Manganese peroxidase (EC 1.11.1.13; Mn2+:H2 O2 oxidoreductase) is another extracellular glycoproteinaceous enzyme used for oxidation of phenolic part of lignin molecule. It also acts on aromatic amines and textile dyes (Ten Have and Teunissen 2001, Zhang et al. 2016), and is being used for bioremediation of many pollutants such as decoloration and degradation of various dyes used in paper, pulp, textile industries, and distilleries. It was first time reported and retrieved from Phanerochaete chrysosporium (Paszczynski et al. 1986). It is isolated also from Basidiomycetes such as Bjerkandera sp. (Palma et al. 2000), Panus tigrinus (Lisov et al. 2003), and Nematoloma frowardii (Hilden et al. 2008). The molecular weight of MnP is around 38 to 62.5 kDa (Sigoillot et al. 2012). The catalytic mechanism of MnP is similar to LiP, but MnP uses Mn2+/Mn3+as redox pair. This enzyme initially oxidizes to form unstable compound I with the reduction of H2 O2 to water. Then, MnP(II) reduces to Mn(III) with the formation of compound II and diffuses out of the enzyme. A series of oxidation undergo chelation with different organic acids like oxalate, fumurate, malate, etc. (Martinez et al. 2005, Sigoillot et al. 2012). Later, Mn(III), the low molecular weight redox mediator with diffusible property, reacts with the substrate and oxidizes it (Goszczynski et al. 1994). The second molecule of Mn(III), along with oxidizing the substrate, reduces the compound II back to original enzyme form. On the other hand, the excess of H2 O2 leads to the formation of compound III which is an inactive form of the enzyme and needs to be converted into active form if next catalytic cycle has to be started (Manavalan et al. 2015) (Figure 2).
Impact of nanomaterials accumulation on the organic carbon associated enzymatic activities in soil
Published in Soil and Sediment Contamination: An International Journal, 2023
Gyan Datta Tripathi, Zoya Javed, Meghana Gattupalli, Kavya Dashora
Enzymes play a very important role in lignin degradation and divided into two main groups: Lignin modifying enzyme (LME), phenol oxidase (laccases) and heme containing peroxidases (POD), particularly lignin, manganese, and multifunctional (versatile) peroxidase, are two types of LME generated by bacteria and the next is lignin degrading auxiliary (LDA) are unable to breakdown lignin on their own (da Silva Coelho-Moreira et al. 2013). Lignin peroxidase (LiP, EC 1.11.1.14) is a glycosylated enzyme that uses hydrogen peroxide (H2O2) to catalyze the oxidation of non-phenolic lignin units and mineralize resistant aromatic chemicals. Lignin oxidation occurs through electron transfer, non-catalytic bond cleavages, and aromatic ring opening (Choinowski, T et al. 1999). . During the early phases of lignin breakdown, the enzyme Manganese peroxidase (MnP,EC 1.11.1.13) plays a critical role (Perez, J et al. 1990).Due to its larger redox potential, MnP promotes more phenolic lignin breakdown than laccase, resulting in the release of carbon dioxide (Ten Have, R., & Teunissen, P. J. 2001). Versatile Peroxidase (VP, EC 1.11.1.16) as the name implies, versatile peroxidase has both LiP and MnP catalytic capabilities. VP was originally extracted from the Bjerkandera fungi, and it was discovered that it could alter lignin without the use of an external mediator (Moreira, P. R et al.2007).
Insights into the catalytic mechanism of ligninolytic peroxidase and laccase in lignin degradation
Published in Bioremediation Journal, 2022
Pankaj Bhatt, Meena Tiwari, Prasoon Parmarick, Kalpana Bhatt, Saurabh Gangola, Muhammad Adnan, Yashpal Singh, Muhammad Bilal, Shakeel Ahmed, Shaohua Chen
Mutation on the active site of enzyme confirmed the possibility of lignin biodegradation, after docking we confirm the Manganese peroxidase contains the Asn131, Asn98, Met94, Glu95 (Figure S2) we replaced amino acids at position 131 and 98 in the enzyme sequence with Methionine (non-polar) and Glycine (non-polar) respectively. It was observed that binding energy and enzyme affinity are not changed, which suggested mutation would be disadvantageous for lignin biodegradation. Further analysis of mutation with different amino acids will give more beneficial results (Table ST3). White rot fungi produce the manganese peroxidase (MnP) found effective in lignin degradation. The Mn2+/Mn3+ redox system act as a mediator of substrate oxidation during lignin catalysis with MnP. The Mn3+ formed during catalysis diffuses away from the active site of MnP enzymes (Wariishi et al. 1989) and participates in oxidative reaction with the substrate (Paszczyński, Huynh, and Crawford 1986). The MnP and Lip both have different reducing substrate. In the presence of hydrogen peroxide Lip able to oxidize the veratryl alcohol into veratryl aldehyde (Kale and Desmukh 2016). The Lip, MnP and Laccase (Lac) were tested for their lignin degradation potential in agricultural waste and industrial pulp delignification. In our docking result, we have seen that the amino acid present in docking site of enzyme manganese peroxidase (Phanerochaete chrysosporium) were Asn131, Asn98, Met94, Glu95. The actual hydrogen bond was formed with Asn131 and Asn98 of manganese peroxidase and substrate lignin (Table ST4).