3.4.23.18	-20°C, in 50 mM sodium acetate, pH 5, stable	
3.4.23.18	20-25°C, pH 2.7, 16 h	
3.4.23.18	4, 7 and 9% of the enzyme's initial activity are lost after 40 days at 4, 28 and -20°C, respectively