Involved in the degradation and detoxification of 5-(hydroxymethyl)furfural (HMF) by mediating its oxidation to furan-2,5-dicarboxylate (FDCA), a biobased platform chemical for the production of polymers. Active with a wide range of aromatic and aliphatic primary alcohols and aldehydes: acts on alcohol groups and requires the spontaneous hydration of aldehyde groups for their oxidation (PubMed:24271187, PubMed:24802551). To a lesser extent, is also able to catalyze the oxidation of thiols that are structurally similar to its alcohol substrates, yielding the corresponding thiocarbonyls (PubMed:25284255). 5-hydroxymethylfurfural + 2 H2O + 3 O2 = 2,5-dicarboxyfuran + 2 H(+) + 3 H2O2 benzylthiol + O2 = benzothialdehyde + H2O2 kcat is 9.9 sec(-1) with 5-(hydroxymethyl)furfural as substrate. kcat is 21.1 sec(-1) with 1,4-benzenedimethanol as substrate. kcat is 14.0 sec(-1) with 1,3-benzenedimethanol as substrate. kcat is 13.5 sec(-1) with benzyl alcohol as substrate. kcat is 7.2 sec(-1) with 4-hydroxybenzyl alcohol as substrate. kcat is 17.1 sec(-1) with 4-aminobenzyl alcohol as substrate. kcat is 9.5 sec(-1) with 4-chlorobenzyl alcohol as substrate. kcat is 17.0 sec(-1) with cinnamyl alcohol as substrate. kcat is 13.3 sec(-1) with 2,4-hexadien-1-ol as substrate. kcat is 21.0 sec(-1) with vanillyl alcohol as substrate (PubMed:24271187). kcat is 2.1 sec(-1) with phenylmethanethiol as substrate. kcat is 3.0 sec(-1) with (4-nitrophenyl)phenylmethanethiol as substrate. kcat is 4.5 sec(-1) with (4-nitrophenyl)methanol as substrate (PubMed:25284255). Optimum pH is 8.0. Optimum temperature is 55 degrees Celsius. Monomer. Because 5-hydroxymethylfurfural can be derived from sugars, the enzyme is of particular interest for the production of biobased plastic materials in an environmentally friendly industrial process. At pH 7.0, phenylmethanethiol is oxidized to the corresponding aromatic thioaldehyde, benzothialdehyde, and no formation of 1,2-dibenzyldisulfane is observed, demonstrating that HMFO does not catalyze the formation of disulfide bonds. At pH 8.0, two products are formed, benzothialdehyde and benzaldehyde; this suggests that the thioaldehyde is slowly hydrated, yielding the aldehyde as the final product. Belongs to the GMC oxidoreductase family.