ENZYME DISTRIBUTION AS A FACTOR IN THE INDEPENDENCE OF BACILLUS CEREUS SPORE GERMINATION FROM L- AND D-CYSTEINE DESULFHYDRASE ACTIVITY

1965 ◽  
Author(s):  
Bernard J. Krask ◽  
George E. Fulk
Keyword(s):  
Bacillus Cereus ◽  
Spore Germination ◽  
Enzyme Distribution ◽  
Cysteine Desulfhydrase

scholarly journals Impact of temperature on Bacillus cereus spore germination in ultra-high temperature chocolate milk

Food Research ◽  
2019 ◽  
pp. 808-813
Author(s):  
Ubong A. ◽  
C.Y. New ◽  
L.C. Chai ◽  
Nur Fatihah A. ◽  
Nur Hasria K. ◽  
...  
Keyword(s):  
High Temperature ◽  
Bacillus Cereus ◽  
Incubation Time ◽  
Spore Germination ◽  
Infection Risk ◽  
Effect Of Temperature ◽  
Harsh Environment ◽  
Chocolate Milk ◽  
Data Gap ◽  
Germination And Growth

Bacillus cereus spores are capable of surviving the harsh environment and more often, they cause great concern to the dairy industry. The current research was conducted to study the effect of temperature on germination and growth of B. cereus spores in UHT chocolate milk; the study was carried out at 8°C, 25°C and 35°C over a span of seven days. The results showed that no growth was observed at 8°C. At 25°C, a rapid increase in growth was observed as early as Day 1, from an initial count of ten spores to 4.01 log10 CFU/mL. Meanwhile, at 35°C, the growth on Day 1 was more rapid in which the count promptly increased to 8.07 log10 CFU/mL. Analysis of graph trend showed that the number of vegetative cells decreased while the number of spores increased with incubation time due to nutrients exhaustion. This study fills up the data gap towards understanding the possible issues that might arise in the actual scenario and at the same time, suggests a suitable approach to minimize infection risk caused by B. cereus spores.

scholarly journals Analysis of Germination Capacity and Germinant Receptor (Sub)clusters of Genome-Sequenced Bacillus cereus Environmental Isolates and Model Strains

2016 ◽  
Vol 83 (4) ◽  
Author(s):  
Alicja K. Warda ◽  
Yinghua Xiao ◽  
Jos Boekhorst ◽  
Marjon H. J. Wells-Bennik ◽  
Masja N. Nierop Groot ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Spore Germination ◽  
Brain Heart Infusion ◽  
Whole Genome Sequence ◽  
Single Spore ◽  
Content Type ◽  
Germination Response ◽  
Natural Isolates ◽  
Heat Activation ◽  
Different Strains

ABSTRACT Spore germination of 17 Bacillus cereus food isolates and reference strains was evaluated using flow cytometry analysis in combination with fluorescent staining at a single-spore level. This approach allowed for rapid collection of germination data under more than 20 conditions, including heat activation of spores, germination in complex media (brain heart infusion [BHI] and tryptone soy broth [TSB]), and exposure to saturating concentrations of single amino acids and the combination of alanine and inosine. Whole-genome sequence comparison revealed a total of 11 clusters of operons encoding germinant receptors (GRs): GerK, GerI, and GerL were present in all strains, whereas GerR, GerS, GerG, GerQ, GerX, GerF, GerW, and GerZ (sub)clusters showed a more diverse presence/absence in different strains. The spores of tested strains displayed high diversity with regard to their sensitivity and responsiveness to selected germinants and heat activation. The two laboratory strains, B. cereus ATCC 14579 and ATCC 10987, and 11 food isolates showed a good germination response under a range of conditions, whereas four other strains (B. cereus B4085, B4086, B4116, and B4153) belonging to phylogenetic group IIIA showed a very weak germination response even in BHI and TSB media. Germination responses could not be linked to specific (combinations of) GRs, but it was noted that the four group IIIA strains contained pseudogenes or variants of subunit C in their gerL cluster. Additionally, two of those strains (B4086 and B4153) carried pseudogenes in the gerK and gerR I (sub)clusters that possibly affected the functionality of these GRs. IMPORTANCE Germination of bacterial spores is a critical step before vegetative growth can resume. Food products may contain nutrient germinants that trigger germination and outgrowth of Bacillus species spores, possibly leading to food spoilage or foodborne illness. Prediction of spore germination behavior is, however, very challenging, especially for spores of natural isolates that tend to show more diverse germination responses than laboratory strains. The approach used has provided information on the genetic diversity in GRs and corresponding subclusters encoded by B. cereus strains, as well as their germination behavior and possible associations with GRs, and it provides a basis for further extension of knowledge on the role of GRs in B. cereus (group member) ecology and transmission to the host.

Control of Bacillus cereus spore germination and outgrowth in cooked rice during chilling by nonorganic and organic apple, orange, and potato peel powders

2017 ◽  
Vol 42 (3) ◽  
pp. e13558 ◽  
Author(s):  
Vijay K. Juneja ◽  
Mendel Friedman ◽  
Tim B. Mohr ◽  
Meryl Silverman ◽  
Sudarsan Mukhopadhyay
Keyword(s):  
Bacillus Cereus ◽  
Spore Germination ◽  
Potato Peel ◽  
Cooked Rice

scholarly journals The Bacillus cereus GerN and GerT Protein Homologs Have Distinct Roles in Spore Germination and Outgrowth, Respectively

2008 ◽  
Vol 190 (18) ◽  
pp. 6148-6152 ◽  
Author(s):  
Adam Senior ◽  
Anne Moir
Keyword(s):  
Amino Acid ◽  
Bacillus Cereus ◽  
Significant Role ◽  
Spore Germination ◽  
Amino Acid Identity ◽  
Wild Type ◽  
Acid Identity ◽  
Germination Response ◽  
Alkaline Conditions ◽  
Spore Outgrowth

ABSTRACT The GerT protein of Bacillus cereus shares 74% amino acid identity with its homolog GerN. The latter is a Na+/H+-K+ antiporter that is required for normal spore germination in inosine. The germination properties of single and double mutants of B. cereus ATCC 10876 reveal that unlike GerN, which is required for all germination responses that involve the GerI germinant receptor, the GerT protein does not have a significant role in germination, although it is required for the residual GerI-mediated inosine germination response of a gerN mutant. In contrast, GerT has a significant role in outgrowth; gerT mutant spores do not outgrow efficiently under alkaline conditions and outgrow more slowly than the wild type in the presence of high NaCl concentrations. The GerT protein in B. cereus therefore contributes to the success of spore outgrowth from the germinated state during alkaline or Na+ stress.

scholarly journals GerN, an Endospore Germination Protein ofBacillus cereus, Is an Na+/H+-K+ Antiporter

2001 ◽  
Vol 183 (20) ◽  
pp. 5896-5903 ◽  
Author(s):  
Thomas W. Southworth ◽  
Arthur A. Guffanti ◽  
Anne Moir ◽  
Terry A. Krulwich
Keyword(s):  
Escherichia Coli ◽  
Bacillus Cereus ◽  
Spore Germination ◽  
Membrane Vesicles ◽  
E Coli ◽  
Channel Proteins ◽  
Partial Inhibition ◽  
Cation Transporters ◽  
Energy Dependent ◽  
Ofbacillus Cereus

ABSTRACT GerN, a Bacillus cereus spore germination protein, exhibits homology to a widely distributed group of putative cation transporters or channel proteins. GerN complemented the Na+-sensitive phenotype of an Escherichia coli mutant that is deficient in Na+/H+ antiport activity (strain KNabc). GerN also reduced the concentration of K+ required to support growth of an E. coli mutant deficient in K+ uptake (strain TK2420). In a fluorescence-based assay of evertedE. coli KNabc membrane vesicles, GerN exhibited robust Na+/H+ antiport activity, with a Km for Na+ estimated at 1.5 mM at pH 8.0 and 25 mM at pH 7.0. Li+, but not K+, served as a substrate. GerN-mediated Na+/H+ antiport was further demonstrated in everted vesicles as energy-dependent accumulation of 22Na+. GerN also used K+ as a coupling ion without completely replacing H+, as indicated by partial inhibition by K+ of H+ uptake into right-side-out vesicles loaded with Na+. K+translocation as part of the antiport was supported by the stimulatory effect of intravesicular K+ on22Na+ uptake by everted vesicles and the dependence of GerN-mediated86Rb+ efflux on the presence of Na+ in trans. The inhibitory patterns of protonophore and thiocyanate were most consistent with an electrogenic Na+/H+-K+antiport. GerN-mediated Na+/H+-K+antiport was much more rapid than GerN-mediated Na+/H+ antiport.

Sign in / Sign up

Export Citation Format

Share Document