Abdelmageed M. Othman
Tahar Mechichi
Pankaj Chowdhary
Waleed B. Suleiman- 1Microbial Chemistry Department, Biotechnology Research Institute, National Research Centre, Giza, Egypt
- 2Laboratoire de Biochimie et de Génie Enzymatique des Lipases, Ecole Nationale d'Ingénieurs de Sfax, University of Sfax, Sfax, Tunisia
- 3Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research (IITR), Lucknow, India
- 4Botany and Microbiology Department, Faculty of Science, Al-Azhar University, Cairo, Egypt
Editorial on the Research Topic
Ligninolytic enzymes and their potential applications
Versatile peroxidase, manganese peroxidase, lignin peroxidase, and laccase are ligninolytic enzymes that have lately achieved substantial economic importance in a variety of sectors including biosensors, pulp, paper, food, textile, detergent, removing endocrine disruptors, and pharmaceutical industries, cosmetics, synthetic chemistry, bioremediation, and biodegradation (Daâssi et al., 2016; Mtibaà et al., 2020; Ben Ayed et al., 2022). Ligninolytic enzymes have played an important role in biotechnological and environmental processes throughout the last few decades. Because of that, ligninolytic microorganisms have piqued the interest of researchers during screening efforts to find unique microbial producers. Ligninolytic enzymes are important players in the global carbon cycle in addition to their commercial uses. Due to the fact that they may be used in a variety of procedures, ligninolytic enzyme complexes are becoming increasingly popular for use in industry and biotechnology (Paul et al., 2023).
Researchers are looking toward enzymatic methods for developing eco-green chemistry technologies because of the drawbacks of chemical and physical methods, growing eco-friendly considerations, legal restrictions, and the increasing body of knowledge in science. Particularly since they frequently benefit the environment and have several potential uses, enzyme-assisted reactions are the focus of a lot of studies (Gad et al., 2022; Hendy et al., 2023). Recent attempts to modify enzymes may help improve the enzyme's stability and activity. As a result, efforts to enhance immobilization techniques must also be increased. Though various methods for immobilizing enzymes have been developed, many of them have the serious drawback of quickly deactivating the enzyme. Innovative immobilization techniques have been developed to create chemically bonded immobilized enzymes superior to free enzymes in terms of stability and activity (Othman et al., 2021, 2023). The ligninolytic enzymes are being researched as prospective environmental enzymes to exchange the conventional mechanical and chemical courses in several industries, comprising nanoparticle-based bio-devices, pharmaceuticals, pulp and paper, and textile industries (Singh et al., 2023). In light of this background, this particular Research Topic has been created to concentrate on innovative, cutting-edge, and promising advancements in the study of microbial ligninolytic enzymes. Twenty-three authors have contributed articles to this Research Topic. In order to meet the demands of the readers, this Research Topic contains four peer-reviewed original research articles, all of which address many aspects of this subject.
Considering that biodelignification is typically sluggish and hard to manage, it is commonly viewed as a low-efficiency process. Li et al. examined the ability of Pleurotus ostreatus to delignify cotton stalks present in the growth medium to increase its effectiveness and comprehend its process. The outcomes showed that all the P. ostreatus strains were capable of preferential lignin degradation in cotton stalks. P. ostreatus generated two liginiolytic enzymes, namely manganese-dependent peroxidase and laccase, with distinguished enzymatic activity levels of 62.39 and 70.17 U/ml, correspondingly; however, no lignin peroxidase could be found. It destroyed lignin by up to 54.04%, largely during the development of its mycelium. Guaiacyl (G) lignin units had a lower G/S ratio than syringyl (S) lignin units, which were more degraded, according to spectroscopic investigations showing major changes in lignin structure. These discoveries will increase the effectiveness of biodelignification and deepen our comprehension of its process.
Microorganisms that break down wood are a rich source of newly discovered enzymes. Different decomposing wood samples were examined by Ali et al., who also found a promising γ-proteobacterial strain known as Serratia proteamaculans AORB19 that naturally released a considerable quantity of laccase enzyme. Both qualitative and quantitative tests were performed to validate the laccase activity of strain AORB19 in the culture medium. Using the one-factor-at-a-time (OFAT) technique, significant cultural factors for laccase synthesis in submerged settings were found. The study's findings point to the strain's and its enzymes' intriguing potential for valorizing lignocellulosic wastes.
The majority of existing techniques for evaluating lytic polysaccharide monooxygenase (LPMO) activity rely on measuring H2O2, a byproduct of LPMO; however, due to H2O2's poor thermostability, most techniques cannot measure the LPMO function in thermophilic fungi. Thermoascus aurantiacus, a thermophilic fungus, was measured for its LPMO activity by Yu et al. using a high-performance liquid chromatography-refractive index detector (HPLC-RID) approach. They examined the oxidation performance of Pichia pastoris-expressed recombinant and three of its mutants. They came to the conclusion that the technique offers an efficient activity test method for LPMOs of thermophilic fungi.
Aflatoxins are naturally occurring, highly poisonous secondary metabolites that seriously endanger human health, pollute the environment across the world, and squander food and feed resources. Aflatoxin detoxification techniques and technology are desperately needed in the long run. The development of three recombinant Kluyveromyces lactis strains, followed by the production of the three manganese peroxidases in these bacteria and the degradation of aflatoxin B1 (AFB1) utilizing the Fermentation supernatants, were all described by Xia et al.. After two treatments, the recombinant strain GG799 (pKLAC1-Phcmnp) supernatants destroyed more than 90% of the AFB1 in the peanut samples. The findings declare the possibility of using the food-grade recombinant yeast strain and its enzyme in the feed or food sectors.
In conclusion, ligninolytic enzymes are now more economically valuable across a range of businesses. Due to their versatility in a range of processes, ligninolytic enzyme complexes are being used increasingly often in biotechnology and industry. This Research Topic is an effort to focus on new, cutting-edge, and intriguing advances in our understanding of microbial ligninolytic enzymes. Future economic and environmental considerations should take into account the low cost of ligninolytic enzyme synthesis using trash found all around us to help address various environmental challenges. In order to increase the potential for enzyme immobilization, studies about using new functional immobilization supports with various functional groups should be taken into consideration. Using green and environmentally friendly alternatives can be a promising area for further research and new potential applications.
Author contributions
All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher's note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
References
Ben Ayed, A., Akrout, I., Albert, Q., Greff, S., Simmler, C., Armengaud, J., et al. (2022). Biotransformation of the fluoroquinolone, levofloxacin, by the white-rot fungus Coriolopsis gallica. J. Fungi 8, 965. doi: 10.3390/jof8090965
Daâssi, D., Prieto, A., Zouari-Mechichi, H., Martínez, M. J., Nasri, M., and Mechichi, T. (2016). Degradation of bisphenol A by different fungal laccases and identification of its degradation products. Int. Biodeterior. Biodegrad. 110, 181–188. doi: 10.1016/j.ibiod.2016.03.017
Gad, A. M., Suleiman, W. B., El-Sheikh, H. H., Elmezayen, H. A., and Beltagy, E. A. (2022). Characterization of cellulase from Geotrichum candidum strain Gad1 approaching bioethanol production. Arab. J. Sci. Eng. 47, 6837–6850. doi: 10.1007/s13369-021-06391-z
Hendy, M. H., Hashem, A. H., Suleiman, W. B., Sultan, M. H., and Abdelraof, M. (2023). Purification, Characterization and anticancer activity of L-methionine γ-lyase from thermo-tolerant Aspergillus fumigatus. Microb. Cell Fact. 22, 8. doi: 10.1186/s12934-023-02019-z
Mtibaà, R., Ezzanad, A., Aranda, E., Pozo, C., Ghariani, B., Moraga, J., et al. (2020). Biodegradation and toxicity reduction of nonylphenol, 4-tert-octylphenol and 2,4-dichlorophenol by the ascomycetous fungus Thielavia sp HJ22: Identification of fungal metabolites and proposal of a putative pathway. Sci. Total Environ. 708, 135129. doi: 10.1016/j.scitotenv.2019.135129
Othman, A. M., Sanromán, Á., and Moldes, D. (2023). Laccase multi-point covalent immobilization: characterization, kinetics, and its hydrophobicity applications. Appl. Microbiol. Biotechnol. 107, 719–733. doi: 10.1007/s00253-022-12352-9
Othman, A. M., Sanromán, M. Á., and Moldes, D. (2021). Kinetic and thermodynamic study of laccase cross-linked onto glyoxyl Immobead 150P carrier: characterization and application for beechwood biografting. Enzyme Microb. Technol. 150, 109865. doi: 10.1016/j.enzmictec.2021.109865
Paul, M., Pandey, N. K., Banerjee, A., Shroti, G. K., Tomer, P., Gazara, R. K., et al. (2023). An insight into omics analysis and metabolic pathway engineering of lignin-degrading enzymes for enhanced lignin valorization. Bioresour. Technol. 379, 129045. doi: 10.1016/j.biortech.2023.129045
Singh, A. K., Iqbal, H. M. N., Cardullo, N., Muccilli, V., Fernández-Lucas, J., Schmidt, J. E., et al. (2023). Structural insights, biocatalytic characteristics, and application prospects of lignin-modifying enzymes for sustainable biotechnology—A review. Int. J. Biol. Macromol. 242, 124968. doi: 10.1016/j.ijbiomac.2023.124968
Keywords: microbial technology, bio-nanotechnology, manganese peroxidase, lignin peroxidase, laccase, ligninolytic enzymes
Citation: Othman AM, Mechichi T, Chowdhary P and Suleiman WB (2023) Editorial: Ligninolytic enzymes and their potential applications. Front. Microbiol. 14:1235206. doi: 10.3389/fmicb.2023.1235206
Received: 05 June 2023; Accepted: 26 June 2023;
Published: 10 July 2023.
Edited and reviewed by: Eric Altermann, Massey University, New Zealand
Copyright © 2023 Othman, Mechichi, Chowdhary and Suleiman. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Abdelmageed M. Othman, othmanam_nrc@yahoo.com; am.othman@nrc.sci.eg