1. Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i., Vídeňská 1083, 142 20 Prague, Czech Republic, Institute of Chemical Technology, Technická 5, 166 28 Prague, Czech Republic, Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, 128 40 Prague, Czech Republic, and Department of Analytical Chemistry, Palacky University, 17.listopadu 12, 771 46 Olomouc, Czech Republic