4.1.3.22	Co2+	Mn2+, Mg2+ or Co2+ required	
4.1.3.22	Mg2+	or an equivalent divalent cation is required	
4.1.3.22	Mg2+	Km for MgCl2: 0.1 mM	
4.1.3.22	Mn2+	Mn2+, Mg2+ or Co2+ required