Enzymatic halogenation captures scientific interest considering its feasibility in modifying compounds for chemical diversity. Currently, majority of flavin-dependent halogenases (F-Hals) were reported from bacterial origin, and as far as we know, none from lichenized fungi. Fungi are well-known producers of halogenated compounds, so using available transcriptomic dataset of Dirinaria sp., we mined for putative gene encoding for F-Hal. Phylogenetic-based classification of the F-Hal family suggested a non-tryptophan F-Hals, similar to other fungal F-Hals, which mainly act on aromatic compounds. However, after the putative halogenase gene from Dirinaria sp., dnhal was codon-optimized,cloned, and expressed in Pichia pastoris, the similar to 63 kDa purified enzymeshowed biocatalytic activity towards tryptophan and an aromatic compound methylhaematommate, which gave the tell-tale isotopic pattern of a chlorinated product atm/z 239.0565 and 241.0552; and m/z 243.0074 and 245.0025, respectively. This study is the start of understanding thecomplexities of lichenized fungal F-hals and its ability to halogenate tryptophan andother aromatic. compounds which can be used as green alternatives forbiocatalysis of halogenated compounds. Biocatalysis, Chlorination, Halogenating enzymes, Lichen, Recombinant proteins, Phenolic compounds, PICHIA-PASTORIS, TRYPTOPHAN 6-HALOGENASE, BIOCATALYTIC SCOPE, PROTEIN, BIOSYNTHESIS, MECHANISM, ATRANORIN, PEPTIDE, OXIDASE