## 5 Applications of Laccases  
According to Business Communication Company (BCC) Research, the market for enzymes for industrial applications is expected to grow from USD 5.5 billion in 2018 to USD 7.0 billion in 2023 [82]. Laccase was first used industrially in the 1990s, and several lacases are now commercially available. Commercially available lacases come from _Tranetes versicolor, Agarus bisporus, Pleurotus ostreatus_ and _Rhus verniciifera_[40,83]. Due to the simplicity of production and purification, the amount of enzyme produced in relation to the costs incurred (the possibility of culturing on agricultural and food industry waste in the presence of readily available and cheap inducers), almost all commercially available lacases come from fungi [6]. Although these organisms have a fairly slow growth rate and the enzymes they produce are unstable under conditions of high temperatures, alkaline stress and high salt contents, they are used in most industrial processes. The reason for this is that fungal lacases have a much higher redox potential than bacterial lacases. New lacases of bacterial origin are currently being sought as they show better stability in a wide range of pH, less susceptibility to inhibitory factors, such as salinity or the presence of metal ions, and are resistant to hot temperatures. In addition, bacterial lacases, compared to fungal lacases, are quite easily subjected to all genetic and protein engineering treatments [84]. White rot fungi (WRF) are a significant source of lacases. Lacase, along with lignin peroxidase and manganese peroxidase, is the main enzyme associated with the ability of WRF to degrade lignin [85,86]. Lignocellulose is the most common source of carbon on earth and accounts for more than 60% of total plant biomass [82]. This includes but is not limited to sawdust and paper mill waste, waste paper, agricultural residues (straw, peelings, cobs, stems, nutshells, nonfood seeds and bagasse), household waste (including sewage), residues from the food industry and solid municipal waste. Lignocellosic feeds are renewable resources that can potentially be used to synthesize fine chemicals, such as biofuels, cellulose and paper, enzymes, composites and animal feed [87]. Unfortunately, lignocellulosiculose is a polymer material with high resistance to degradation, thanks to lignin, a polymer composed of aromatic alcohol monomers [88]. Enzymatic delignification with lacases depolymerizes the lignin, which increases the bioavailability of the resulting biomass for cellulolytic enzymes at a later stage. The advantages of the enzymatic pre-treatment of lignin compared to other methods include the production of fewer by-products, including those toxic to the environment, low energy input, significant biomass conversion and mild operating conditions [87,89,90]. The lacases of the halophilic bacteria _Aquisalibacillus elongatus_ and _Chromolobacter salezicgens_ showed the ability to delignify beet pulp and almond shell biowaste, respectively. The enzymes were highly stable extracellular lacases, resistant to the presence of organic solvents, salts, metals, inhibitors and surfactants in the reaction environment and showed high catalytic efficiency in a wide range of phenolic and nonphenolic substrates differentiated in terms of structure and redox potential. Lacases can be an alternative to chemical methods of lignocellulosic fiber processing, the extraction of lignocellulosic biowaste or the delignification of lignin and lignin-derived industrial waste [91,92]. The processing of plant biomass and delignification of agro-industrial materials leads to the simultaneous production of glucose, which can be further used to produce bioethanol [87,90]. During the production of bioethanol from lignocellulosic, in addition to a mixture of sugars, phenolic compounds are also formed that inhibit yeast fermentation and, thus, the production of alcohol. To increase fuel ethanol production from renewable feedstocks, _T. versicolor_ lacase was expressed under the control of the PGK1 promoter in _S.