[1] Univ Gottingen, Inst Microbiol & Genet, Gottingen Genom Lab, D-37077 Gottingen, Germany
[2] Univ Gottingen, Inst Microbiol & Genet, Dept Mol Genet & Preparat Mol Biol, D-37077 Gottingen, Germany
[3] Univ Gottingen, Inst Microbiol & Genet, Dept Gen & Appl Microbiol, D-37077 Gottingen, Germany
[4] Univ Regensburg, D-93053 Regensburg, Germany