# _Bacillus_ sp. GLN Laccase Characterization: Industry and Biotechnology Implications
## 4 Discussion  
Bacterial lacases have shown a wealth of potential in sustainable development owing to their versatility. These enzymes demonstrated enhanced biocatalytic tendencies towards a broad range of substrates, high thermal stability, salt tolerance, optimal functionality at various pH conditions, organic solvent, and surfactant compatibility [24, 25]. Due to the possible influence of environmental factors on the metabolic diversity of the microbial community, researchers have explored various habitats, including but not limited to wastewater samples [19], paper mills [26], decomposed wood samples [27, 28], sawdust, dairy effluent soil samples [29], and textile industry effluent samples [30] for the isolation of bacteria with high license activities. This study used decaying wood biomass to isolate bacteria capable of secreting lacase in the extracellular medium. The exo-production of enzymes is advantageous economically, as it subsidizes downstream processing, while enhancing copious enzyme recovery. The qualitative assay has been considered relevant in evaluating multiple bacterial strains, as it identifies potential isolates and minimizes time and resource wastage. Studies on the lacase production potential of bacterial isolates have employed one substrate [30] or multiple substrates [27] when evaluating extracellular lacase activity using plate assay. The ability of the bacterial strains to oxidize more than one substrate during the qualitative screening is evidence of their broad substrate specificity \begin{table}
\begin{tabular}{c c c} \hline
**Metal Ions** & **Concentration (mM)** & **Residual Activity (\%) a** \\ \hline Control & - & 100 \(\pm\) 2.65 \\ CaCl\({}_{2}\) & 1 & 86.37 \(\pm\) 3.337 \\ MgCl\({}_{2}\) & 1 & 96.42 \(\pm\) 6.34 \\ FeCl\({}_{2}\) & 1 & 104.32 \(\pm\) 1.53 \\ MnSO\({}_{4}\) & 1 & 96.76 \(\pm\) 0.32 \\ ZnSO\({}_{4}\) & 1 & 92.67 \(\pm\) 0.56 \\ CuSO\({}_{4}\) & 1 & 110.68 \(\pm\) 2.17 \\ NiCl & 1 & 93.87 \(\pm\) 0.64 \\ KCl & 1 & 93.70 \(\pm\) 6.02 \\ \hline \end{tabular} \({}^{\ddagger}\) The results were presented as mean values of three experimental analyses.  
\end{table} 
Table 4: Metal ions’ influence on the GLN lacase stability. \begin{table}
\begin{tabular}{c c c} \hline
**Chemical Agents** & **Concentration (mM)** & **Residual Activity (\%) a** \\ \hline Control & - & 100 \(\pm\) 0.76 \\ SDS & 100 & 53.67 \(\pm\) 0.13 \\ EDTA & 100 & 58.33 \(\pm\) 0.51 \\ NaN\({}_{3}\) & 100 & 65.14 \(\pm\) 1.26 \\ Urea & 100 & 63.08 \(\pm\) 3.17 \\ NaCl & 100 & 63.98 \(\pm\) 0 \\ \hline \end{tabular} \({}^{\text{a}}\) The results were presented as mean values of three experimental analyses.  
\end{table} 
Table 3: Influence of enzyme inhibitors on GLN lacase stability. and multifaceted application potential. Different substrates have been employed for the assessment of extracellular lactose production on solid media, and they include guaiacol, 1-naphthol, 2, 6-dimethoxy phenol, ABTS, syringalazine, lignin, ferbamine, and tannic acid, among others [19; 31; 32; 33]. The substrate oxidation pattern on the plate assay by the bacterial strains under investigation suggests their metabolic diversity. The extracellular lactose production by the bacterial strains that oxidized both guaiacol and \(\alpha\)-naphthol on solid media further demonstrated the isolates' peculiarity and their distinct enzyme machinery. WP-2 showed a robust expression system by displaying copious lacase titer in a submerged state fermentation. The isolate WP-2 was identified as _Bacillus_ sp. GLN based on its high percentage of sequence similarity with the _B. cereus_ sensu lato group. This group of bacteria has been reported to possess numerous mobile genetic elements, which enhance their adaptation and versatility [34]. Consequently, this group has been implicated in numerous ecological functions due to their diverse metabolic capacities, contributing to environmental sustainability [35].