title: Use of proteomic analysis to elucidate the role of calcium in acetone-butanol-ethanol fermentation by Clostridium beijerinckii NCIMB 8052.
abstract: Calcium carbonate increases growth, substrate utilization, and acetone-butanol-ethanol (ABE) fermentation by Clostridium beijerinckii NCIMB 8052. Toward an understanding of the basis for these pleiotropic effects, we profiled changes in the C. beijerinckii NCIMB 8052 proteome that occur in response to the addition of CaCO(3). We observed increases in the levels of different heat shock proteins (GrpE and DnaK), sugar transporters, and proteins involved in DNA synthesis, repair, recombination, and replication. We also noted significant decreases in the levels of proteins involved in metabolism, nucleic acid stabilization, sporulation, oxidative and antibiotic stress responses, and signal transduction. We determined that CaCO(3) enhances ABE fermentation due to both its buffering effects and its ability to influence key cellular processes, such as sugar transport, butanol tolerance, and solventogenesis. Moreover, activity assays in vitro for select solventogenic enzymes revealed that part of the underpinning for the CaCO(3)-mediated increase in the level of ABE fermentation stems from the enhanced activity of these catalysts in the presence of Ca(2+). Collectively, these proteomic and biochemical studies provide new insights into the multifactorial basis for the stimulation of ABE fermentation and butanol tolerance in the presence of CaCO(3).
authors.affiliation: Department of Animal Sciences, The Ohio State University, and Ohio State Agricultural Research and Development Center (OARDC), Wooster, Ohio, USA.
authors.forename: Bei
authors.initials: B
authors.lastname: Han
authors.forename: Victor
authors.initials: V
authors.lastname: Ujor
authors.forename: Lien B
authors.initials: LB
authors.lastname: Lai
authors.forename: Venkat
authors.initials: V
authors.lastname: Gopalan
authors.forename: Thaddeus Chukwuemeka
authors.initials: TC
authors.lastname: Ezeji
mesh_terms: D000096:Acetone / Q000378:metabolism*; D000440:Butanols / Q000378:metabolism*; D002119:Calcium Carbonate / Q000378:metabolism*; D046970:Clostridium beijerinckii / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D053858:Metabolic Networks and Pathways; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods
chemical_list: D000440:Butanols; D020543:Proteome; D000096:Acetone; D000431:Ethanol; D002119:Calcium Carbonate