2,4-Dichlorophenol biotransformation using immobilized marine halophilic Bacillus subtilis culture and laccase enzyme: application in wastewater treatment

Abstract

Background 2,4-Dichlorophenol (2,4-DCP) is a very toxic aromatic compound for humans and the environment and is highly resistant to degradation. Therefore, it is necessary to develop efficient remediation and cost-effective approaches to this pollutant. Microbial enzymes such as laccases can degrade phenols, but limited information is known about immobilized bacterial laccase and their reuse. Methods Immobilization of marine halophilic Bacillus subtilis AAK cultures via entrapment and adsorption techniques and degradation of different phenolic compounds by immobilized cells were estimated. Partial purification and immobilization of laccase enzymes were carried out. In addition, the biodegradation of 2,4-DCP and others contaminated by wastewater was investigated. Results Immobilization of cells and partially purified laccase enzymes by adsorption into 3% alginate increased 2,4-DCP biotransformation compared with free cells and free enzymes. In addition, the reuse of both the immobilized culture and laccase enzymes was evaluated. The highest removal of 2,4-DCP from pulp and paper wastewater samples inoculated by immobilized cells and the immobilized enzyme was 90% and 95%, respectively, at 50 h and 52 h of incubation, compared to free cells and free enzyme. Conclusion The results of this study have revealed the immobilization of a biocatalyst and its laccase enzyme as a promising technique for enhancing the degradation of 2,4-DCP and other toxic phenolic and aromatic compounds. The reuse of the biocatalyst and its laccase enzyme enabled the application of this cost-effective bioremediation strategy.

Oxidoreductase enzymes: Characteristics, applications, and challenges as a biocatalyst

“…The marine halophilic Bacillus subtilis AAK bacteria were immobilized by entrapment and adsorption on 3% alginate, and used for biodegradation of the toxic aromatic compound 2,4-diclorophenol by intracellular laccase, with a 90% removal at 50 h incubation, compared to free cells. 96 Laccase enzymes have also been used as biosensors for the detection of dopamine for biomedical purposes, using silica nanoparticles functionalized with phytic acid as support. 97 Despite their versatility and ability to transform a large number of compounds, laccase has not been widely used on a large scale.…”

“…The discoloration percentages toward this compound were ≥95% after five bioconversion cycles. The marine halophilic Bacillus subtilis AAK bacteria were immobilized by entrapment and adsorption on 3% alginate, and used for biodegradation of the toxic aromatic compound 2,4‐diclorophenol by intracellular laccase, with a 90% removal at 50 h incubation, compared to free cells 96 . Laccase enzymes have also been used as biosensors for the detection of dopamine for biomedical purposes, using silica nanoparticles functionalized with phytic acid as support 97 …”

L-glutaminase Production from New Halophilic Marine Streptomyces griseorubens NAHE Isolated from Mangrove Sediment, Red Sea, Egypt

“…These advantages include increased cell density, continuous utilization, improved cell activity, retention of plasmid-bearing cells, prevention of interfacial inactivation, enhanced productivity, safeguarding against shear forces and acidification in the environment, and resistance to many environmental conditions (Bayat et al, 2015;Mitra & Mukhopadhyay, 2016). Various immobilization techniques have been employed to produce organic acids, enzymes, and amino acids and to carry out the bioremediation of hazardous pollutants (Farag et al, 2022).…”

A Highly Purified L-Glutaminase From Immobilized Pseudomonas Sp. Ras123 Cultures With Antitumor and Antibacterial Activities

“…Previous research has shown that marine habitats are a suitable source for the creation of a variety of enzymes with unique qualities such as stability in severe conditions and salt tolerance (Pandian et al, 2014). Immobilized cell systems have been increasingly popular for a variety of biotechnological applications, including bioremediation (Farag et al, 2022), and the production of metabolites such as organic acids, alcohols, antibiotics, and enzymes (El-Borai et al, 2022). Immobilization of whole cell methods has sparked a lot of interest because of its potential to improve bioprocesses and increase product output.…”