Tyrosinase and laccase-producing Bacillus aryabhattai TFG5 and its role in the polymerization of phenols

Abstract

Background Tyrosinases and laccases are oxidoreductase enzymes that are used widely in the food, feed, textile, and biofuel industries. The rapidly growing industrial demand for bacterial oxido-reductases has encouraged research on this enzyme worldwide. These enzymes also play a key role in the formation of humic substances (HS) that are involved in controlling the biogeochemical carbon cycle, providing nutrients and bio-stimulants for plant growth, and interacting with inorganic and organic pollutants besides increasing carbon sequestration and mitigating greenhouse gas emission in the environment. The present study aimed to screen and characterize extracellular tyrosinase and laccase-producing soil bacteria that could be utilized in the polymerization of phenols. Results Twenty isolates from different soil samples collected from forest ecosystems were characterized through ARDRA using restriction digestion with AluI, HpaII, and HaeIII restriction enzymes. The results of Hierarchical Cluster Analysis (HCA) revealed a 60 % similarity coefficient among 13 out of 20 isolates, of which, the isolate TFG5 exhibited only 10 % similarity when compared to all the other isolates. The isolate TFG5 exhibited both tyrosinase (1.34 U.mL− 1) and laccase (2.01 U.mL− 1) activity and was identified as Bacillus aryabhattai. The increased polymerization activity was observed when B. aryabhattai TFG5 was treated with phenols. The monomers such as catechol, p-Hydroxy benzoic acid, ferulic acid, and salicylic acid were polymerized efficiently, as evidenced by their FT-IR spectra depicting increased functional groups compared to the standard mushroom tyrosinase. Conclusions The polymerization ability of B. aryabhattai TFG5 could be applied to phenol-rich wastewater treatment for efficient precipitation of phenols. Furthermore, tyrosinases can be used for enhancing the synthesis of HS in soil.

The Novel Role of Tyrosinase Enzymes in the Storage of Globally Significant Amounts of Carbon in Wetland Ecosystems

“…124 The sampling sites of Verrucomicrobium spinosum (freshwater lake), 124 Rhizobium etli (agricultural soil as a plant symbiont 109 ), and Burkholderia thailandensis (environmental samples 99 ) demonstrate that TYRs of the second general architecture are commonly present in soil samples. The TYRs from Bacillus megaterium (MW ∼ 31 kDa) 95 and Bacillus aryabhattai (MW ∼ 34 kDa) 138 exemplify a third general TYR architecture. They are produced in their active forms, without a caddie protein or a C-terminal extension and are, therefore, permanently active and secreted into the environment (Figure S4, III).…”

“…The TYRs from Bacillus megaterium (MW ∼ 31 kDa) and Bacillus aryabhattai (MW ∼ 34 kDa) exemplify a third general TYR architecture. They are produced in their active forms, without a caddie protein or a C-terminal extension and are, therefore, permanently active and secreted into the environment (Figure S4, III) .…”

“…They are produced in their active forms, without a caddie protein or a C-terminal extension and are, therefore, permanently active and secreted into the environment (Figure S4, III) . Since Bacillus megaterium and Bacillus aryabhattai have been isolated from soil samples, , a possible involvement of these enzymes in soil carbons storage can be suggested, as well. Due to the natural habitats of their respective host organisms, all three general TYR architectures have been demonstrated to be present in soil and, therefore, to potentially impact soil geochemistry, in concert with other phenol oxidases.…”

Agriculture Waste Management - A Case study on Bowenpally Mandi

“…Laccases have also been used in the delignification of pulp, bleaching of textiles and carcinogenic dyes, detoxification of water and soils, removal of phenolics from wines, improving adhesive properties of lignocellulosic products, determination of bilirubin levels in serum, and transformation of antibiotics and steroids (Dougherty et al, 2012;Sakurai and Kataoka, 2007). Furthermore, tyrosinase and laccaseproducing Bacillus aryabhattai TFG5 known to enhance the synthesis of humic substances from coir pith waste (Muniraj et al, 2021a;2021b). In addition, laccases have demonstrated potential for use in biosensors, bioreactors, and biofuel cells (Shleev et al, 2005).…”

Immobilization of Biomass Materials for Removal of Refractory Organic Pollutants from Wastewater

“…Currently, the desired bioremediation materials can be obtained from various sources, such as the plants Acalypha indica [ 10 ], Saccharomyces [ 11 ], Aspergillus [ 12 ], white-rot fungi [ 13 ], and algae [ 14 , 15 ], which have been widely used for the removal of organic pollutants from wastewater. In addition, it has been reported that peroxidases [ 16 ] and laccases [ 17 , 18 ] among biological enzymes also degrade organic pollutants; however, existing studies have shown that free microorganisms/enzymes have low stability, short service lives, and are not easy to separate and recover, which limits their further industrial application [ 19 ].…”