Catalyzes the FAD-dependent oxidative deamination of glycine, leading to glyoxylate, ammonia and hydrogen peroxide (PubMed:26920475). Is also able to act on various amines and D-amino acids to yield the corresponding alpha-keto acids, ammonia/amine, and hydrogen peroxide (By similarity). Can also oxidize the herbicide glyphosate (N-phosphonomethylglycine), and thus may be involved in the degradation pathway that allows B.licheniformis J33-8 to grow with glyphosate as the sole source of carbon (PubMed:26920475). Is essential for thiamine biosynthesis since the oxidation of glycine catalyzed by ThiO generates the glycine imine intermediate (dehydroglycine) required for the biosynthesis of the thiazole ring of thiamine pyrophosphate (By similarity). glycine + H2O + O2 = glyoxylate + H2O2 + NH4(+) glyphosate + H2O + O2 = aminomethylphosphonate + glyoxylate + H(+) + H2O2 H2O + N-ethylglycine + O2 = ethylamine + glyoxylate + H2O2 H2O + O2 + sarcosine = glyoxylate + H2O2 + methylamine D-alanine + H2O + O2 = H2O2 + NH4(+) + pyruvate Binds 1 FAD per subunit. kcat is 0.31 sec(-1) with glycine as substrate. kcat is 0.08 sec(-1) with glyphosate as substrate. Optimum pH is 8.5. Displays over 60% of maximum activity at pH 8.0-10. Optimum temperature is 40 degrees Celsius. Retains 60% of the maximum activity at 0 degree Celsius, suggesting it is a cold-adapted enzyme. Cofactor biosynthesis; thiamine diphosphate biosynthesis. Homotetramer. This glyphosate-degrading enzyme could be of potential use in agricultural biotechnology for the development of new-generation herbicide-resistant plants. The SCF-4 mutant obtained by engineering shows significant improved catalytic efficiency towards glyphosate, and a better affinity to glyphosate than that reported for glyphosate oxidoreductase GOX in a Monsanto's patent. Belongs to the DAO family. ThiO subfamily.