title: High pressure germination of Bacillus subtilis spores with alterations in levels and types of germination proteins.
abstract: OBJECTIVE
  Examine effects of different levels and types of nutrient germinant receptors (GRs) and other germination proteins on Bacillus subtilis spore germination by a moderate high pressure (mHP) (150 megaPascals (MPa)) that triggers germination through GRs, and a very high pressure (vHP) (550 MPa) that triggers spore germination independent of GRs.
  
  
  RESULTS
  The Moderate HP (mHP) and vHP germination kinetics of B. subtilis spores with large variations in levels of GRs and other germination proteins, including the GerD protein and the SpoVA proteins that comprise a spore membrane channel that is likely opened by vHP were measured.
  
  
  CONCLUSIONS
  GR levels were the major factor determining mHP germination rates. However, other factors modulated mHP germination rates including (i) relative levels of individual GRs (GerA, GerB, GerK), as mHP affected different GRs differently; (ii) levels of a recently identified small protein that may be a GR subunit; and (iii) a dominant negative mutation in gerD that eliminates GR-dependent nutrient germination. In contrast, the alterations in germination proteins had no major effect on vHP germination, except for reduction of SpoVA protein levels.
  
  
  CONCLUSIONS
  With the increasing use of HP for food processing, this study provides new information on factors that modulate HP germination of spores for potential application of HP technology to achieve food sterility.
authors.affiliation: US Army-Natick Soldier RD&E Center, Warfighter Directorate, Natick, MA, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Doona
authors.forename: S
authors.initials: S
authors.lastname: Ghosh
authors.forename: F F
authors.initials: FF
authors.lastname: Feeherry
authors.forename: A
authors.initials: A
authors.lastname: Ramirez-Peralta
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
authors.forename: H
authors.initials: H
authors.lastname: Chen
authors.forename: P
authors.initials: P
authors.lastname: Setlow
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D011312:Pressure; D013171:Spores, Bacterial / Q000254:growth & development; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D014157:Transcription Factors
keywords: Bacillus; germinant receptor; high pressure; spore germination; spores