Inhibition of l-alanine triggered Bacillus cereus T spore germination and outgrowth by fatty acids and glyceryl monododecanoate

1994 ◽  
Vol 11 (5) ◽  
pp. 385-396 ◽  
Author(s):  
L.H. Ababouch ◽  
F. Bouquartacha ◽  
F.F. Busta
Keyword(s):  
Fatty Acids ◽  
Bacillus Cereus ◽  
Spore Germination

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.

Self-inhibition of arthrospore germination in Geotrichum candidum

1973 ◽  
Vol 19 (8) ◽  
pp. 943-947 ◽  
Author(s):  
S. D. Steele
Keyword(s):  
Fatty Acids ◽  
Oxygen Uptake ◽  
Spore Germination ◽  
Vegetative Growth ◽  
Carbon Sources ◽  
Somatic Growth ◽  
Geotrichum Candidum ◽  
The Self ◽  
Spore Concentration ◽  
Inhibitor Concentration

An attempt to isolate a self-inhibitor of spore germination in Geotrichum candidum Link was unsuccessful because of the instability of the self-inhibitor. The ability of different carbon sources to stimulate germination and support somatic growth was tested in self-inhibitory conditions. Acetate, fructose, galactose, and glycerol supported both germination and somatic growth. All the fatty acids tested allowed germination but were unable to support vegetative growth; conversely mannitol could not induce germination but did support vegetative growth. Measurements of oxygen uptake by germinating arthrospores at various arthrospore concentrations showed a decrease in oxygen uptake per spore as the spore concentration (= self-inhibitor concentration) increased. Oxygen uptake per spore by dormant arthrospores also decreased with increasing spore concentration. Spore age was another factor influencing oxygen uptake by dormant spores; oxygen uptake per spore decreased with increasing spore age up to 7 days. Continued aging did not decrease the rate of oxygen uptake any further.

scholarly journals Phytochemical Investigations of Lonchocarpus Bark Extracts from Monteverde, Costa Rica

2014 ◽  
Vol 9 (4) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Caitlin E. Deskins ◽  
Bernhard Vogler ◽  
Noura S. Dosoky ◽  
Bhuwan K. Chhetri ◽  
William A. Haber ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Antioxidant Activity ◽  
Costa Rica ◽  
Bacillus Cereus ◽  
Cytotoxic Activity ◽  
Antioxidant Activities ◽  
Antimicrobial Activities ◽  
Mcf 7

The acetone bark extracts of three species of Lonchocarpus from Monteverde, Costa Rica, L. atropurpureus, L. oliganthus, and L. monteviridis, were screened for antibacterial, cytotoxic, and antioxidant activities. L. orotinus extract was antibacterial against Bacillus cereus (MIC = 39 μg/mL), while L. monteviridis exhibited the most antioxidant activity. None of the Lonchocarpus extracts showed cytotoxic activity against MCF-7 cells. Fatty acids and atraric acid were isolated and purified from L. atropurpureus bark, fatty acids and loliolide from L. oliganthus bark, and leonuriside A and β-D-glucopyranos-1-yl N-methylpyrrole-2-carboxylate from L. monteviridis bark. Atraric acid showed cytotoxic and antimicrobial activities.

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.

Factors affecting the relative ratio of fatty acids in Bacillus cereus

1971 ◽  
Vol 17 (2) ◽  
pp. 269-275 ◽  
Author(s):  
Toshi Kaneda
Keyword(s):  
Fatty Acids ◽  
Bacillus Cereus ◽  
Culture Medium ◽  
Acid Synthesis ◽  
Growth Conditions ◽  
Factors Affecting ◽  
Normal Series ◽  
Branched Chain Fatty Acids ◽  
Branched Chain ◽  
Chain Fatty Acids

Factors affecting relative proportions of long-chain fatty acids produced by the growing cells of Bacillus cereus have been studied. The organism produces nine branched (i-C12, i-C13, i-C14, i-C15, i-C16, i-C17, a-C13, a-C15, and a-C17), two normal (n-C14 and n-C16), and four monounsaturated (i-C161−, i-C17−1, a-C171−, and n-C161−), in addition to some minor fatty acids. On the basis of biosynthetic relationships these are grouped into four series: anteiso odd-numbered, iso odd-numbered, iso even-numbered, and normal even-numbered. The proportion of the normal series of fatty acids is generally not changed by varying growth conditions. The proportions of the three series of branched-chain fatty acids, however, are greatly affected depending upon growth phase and culture medium used. Younger cells tend to produce the four series in a closer ratio (1.5/1.8/0.8/1.0), whereas older cells produce four series in a wider ratio (1/2.2/0.8/1.0).The precursors of the terminal portions of branched-chain fatty acids, L-leucine, L-isoleucine, L-valine, and the related substrates, affected greatly the ratio of the three series of branched-chain fatty acids. Apparently the synthesis of iso odd-numbered acids is more tightly controlled than the synthesis of the two other series of fatty acids. Data suggest that this regulation is very likely to be due to the substrate specificity of the enzyme(s) involved in the fatty acid synthesis, rather than the relative availability of the precursors.

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