title: Role of the gerA operon in L-alanine germination of Bacillus licheniformis spores.
abstract: BACKGROUND
  The genome of Bacillus licheniformis DSM 13 harbours three neighbouring open reading frames showing protein sequence similarities to the proteins encoded from the Bacillus subtilis subsp. subtilis 168 gerA operon, GerAA, GerAB and GerAC. In B. subtilis, these proteins are assumed to form a germinant receptor involved in spore germination induced by the amino acid L-alanine.
  
  
  RESULTS
  In this study we show that disruption of the gerAA gene in B. licheniformis MW3 hamper L-alanine and casein hydrolysate-triggered spore germination, measured by absorbance at 600 nm and confirmed by phase contrast microscopy. This ability was restored by complementation with a plasmid-borne copy of the gerA locus. Addition of D-alanine in the casein hydrolysate germination assay abolished germination of both B. licheniformis MW3 and the complementation mutant. Germination of both B. licheniformis MW3 and the gerA disruption mutant was induced by the non-nutrient germinant Ca2+-Dipicolinic acid.
  
  
  CONCLUSIONS
  These results demonstrate that the B. licheniformis MW3 gerA locus is involved in germination induced by L-alanine and potentially other components present in casein hydrolysate.
authors.affiliation: Nofima AS, Department of Process Technology, Måltidets hus, Richard Johnsens gate 4, P Box 8034, N-4068 Stavanger, Norway.
authors.forename: Irene S
authors.initials: IS
authors.lastname: Løvdal
authors.forename: Cecilie
authors.initials: C
authors.lastname: From
authors.forename: Elisabeth H
authors.initials: EH
authors.lastname: Madslien
authors.forename: Kristin Cecilia S
authors.initials: KC
authors.lastname: Romundset
authors.forename: Elin
authors.initials: E
authors.lastname: Klufterud
authors.forename: Jan Thomas
authors.initials: JT
authors.lastname: Rosnes
authors.forename: Per Einar
authors.initials: PE
authors.lastname: Granum
mesh_terms: D000409:Alanine / Q000378:metabolism*; D001407:Bacillus / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002364:Caseins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009876:Operon; D013171:Spores, Bacterial / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D002364:Caseins; D008565:Membrane Proteins; C475729:casein hydrolysate; D000409:Alanine