Displays some glucuronoyl esterase activity in vitro, since it is able to hydrolyze methyl 4-O-methyl-D-glucopyranosyluronate, allyl D-glucuronate, benzyl D-glucuronate and D-glucuronic acid methyl ester. However, esters of glucuronic acid are probably not its biological substrate, as they are not present in the marine environment. Can also hydrolyze a range of other esters, including p-nitrophenyl acetate. More likely biologically-relevant substrates for MZ0003 and other marine bacterial CE15s are algal cell wall polysaccharides, as these would be readily available in this environment and could be used as energy sources. Does not require metal ions for activity. Is inhibited by PMSF and by NaF in vitro, which is consistent with the catalytic nucleophile being a serine. kcat is 8.9 sec(-1) with p-nitrophenyl acetate as substrate (in the absence of NaCl). kcat is 12.78 sec(-1) with p-nitrophenyl acetate as substrate (in the presence of 1M NaCl). Optimum pH is 8.0. Shows more than 60% of its maximum activity in the pH range of 7.0-9.5. 20% of the activity is retained at low pH range and at pH 10.5, while no catalytic activity is found at pH 5.0 or 10.5. Optimum temperature is 35 degrees Celsius with p-nitrophenyl acetate as substrate. Above 35 degrees Celsius, activity significantly decreases, while 30% of the maximum activity is recorded at 10 degrees Celsius. Belongs to the carbohydrate esterase 15 (CE15) family.