title: Effects of carbon dioxide on growth of proteolytic Clostridium botulinum, its ability to produce neurotoxin, and its transcriptome.
abstract: The antimicrobial gas carbon dioxide is frequently used in modified atmosphere packaging. In the present study, the effects of CO2 (10 to 70%, vol/vol) on gene expression (measured using quantitative reverse transcription-PCR and a whole-genome DNA microarray) and neurotoxin formation (measured using an enzyme-linked immunosorbent assay [ELISA]) by proteolytic Clostridium botulinum type A1 strain ATCC 3502 were studied during the growth cycle. Interestingly, in marked contrast to the situation with nonproteolytic C. botulinum types B and E, CO2 had little effect on any of these parameters. At all CO2 concentrations, relative expression of neurotoxin cluster genes peaked in the transition between exponential and stationary phases, with evidence of a second rise in expression in late stationary phase. Microarray analysis enabled identification of coding sequences whose expression profiles matched those of the neurotoxin cluster. Further research is needed to determine whether these are connected to neurotoxin formation or are merely growth phase associated.
authors.affiliation: Institute of Food Research, Norwich, United Kingdom.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Artin
authors.forename: David R
authors.initials: DR
authors.lastname: Mason
authors.forename: Carmen
authors.initials: C
authors.lastname: Pin
authors.forename: Jenny
authors.initials: J
authors.lastname: Schelin
authors.forename: Michael W
authors.initials: MW
authors.lastname: Peck
authors.forename: Elisabet
authors.initials: E
authors.lastname: Holst
authors.forename: Peter
authors.initials: P
authors.lastname: Rådström
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Carter
mesh_terms: D001483:Base Sequence; D001905:Botulinum Toxins / Q000096:biosynthesis* / Q000235:genetics; D001906:Botulism / Q000209:etiology; D002245:Carbon Dioxide / Q000494:pharmacology*; D003014:Clostridium botulinum / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D005516:Food Microbiology; D018857:Food Packaging; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D005798:Genes, Bacterial; D006801:Humans; D005810:Multigene Family; D009498:Neurotoxins / Q000096:biosynthesis* / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis
chemical_list: D017931:DNA Primers; D009498:Neurotoxins; D002245:Carbon Dioxide; D001905:Botulinum Toxins