title: Unravelling the genetic basis for competence development of auxotrophic Bacillus licheniformis 9945A strains.
abstract: Bacterial natural genetic competence - well studied in Bacillus subtilis - enables cells to take up and integrate extracellularly supplied DNA into their own genome. However, little is known about competence development and its regulation in other members of the genus, although DNA uptake machineries are routinely encoded. Auxotrophic Bacillus licheniformis 9945A derivatives, obtained from repeated rounds of random mutagenesis, were long known to develop natural competence. Inspection of the colony morphology and extracellular enzyme secretion of two of these derivatives, M28 and M18, suggested that regulator genes are collaterally hit. M28 emerged as a 14 bp deletion mutant concomitantly displaying a shift in the reading frame of degS that encodes the sensor histidine kinase, which is part of the molecular switch that directs cells to genetic competence, the synthesis of extracellular enzymes or biofilm formation, while for M18, sequencing of the suspected gene revealed a 375 bp deletion in abrB, encoding the major transition state regulator. With respect to colony morphology, enzyme secretion and competence development, both of the mutations, when newly generated on the wild-type B. licheniformis 9945A genetic background, resulted in phenotypes resembling M28 and M18, respectively. All of the known naturally competent B. licheniformis representatives, hitherto thoroughly investigated in this regard, carry mutations in regulator genes, and hence genetic competence observed in domesticated strains supposedly results from deregulation.
authors.affiliation: Westfälische Wilhelms-Universität Münster, Institut für Molekulare Mikrobiologie und Biotechnologie, Corrensstrasse 3, 48149 Münster, Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Jakobs
authors.affiliation: Westfälische Wilhelms-Universität Münster, Institut für Molekulare Mikrobiologie und Biotechnologie, Corrensstrasse 3, 48149 Münster, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hoffmann
authors.affiliation: Westfälische Wilhelms-Universität Münster, Institut für Molekulare Mikrobiologie und Biotechnologie, Corrensstrasse 3, 48149 Münster, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Grabke
authors.affiliation: Georg-August-University Goettingen, Department of Genomic and Applied Microbiology, Goettingen Genomics Laboratory, Grisebachstrasse 8, 37077 Göttingen, Germany.
authors.forename: Stefania
authors.initials: S
authors.lastname: Neuber
authors.affiliation: Georg-August-University Goettingen, Department of Genomic and Applied Microbiology, Goettingen Genomics Laboratory, Grisebachstrasse 8, 37077 Göttingen, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Liesegang
authors.affiliation: Georg-August-University Goettingen, Department of Genomic and Applied Microbiology, Goettingen Genomics Laboratory, Grisebachstrasse 8, 37077 Göttingen, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Volland
authors.affiliation: Westfälische Wilhelms-Universität Münster, Institut für Molekulare Mikrobiologie und Biotechnologie, Corrensstrasse 3, 48149 Münster, Germany.
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Meinhardt
mesh_terms: D001407:Bacillus / Q000235:genetics* / Q000302:isolation & purification; D061269:DNA Transformation Competence; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D050505:Mutant Proteins