scholarly journals Pressure and Temperature Combined With Microbial Supernatant Effectively Inactivate Bacillus subtilis Spores

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingyu Li ◽  
Yaxin Sun ◽  
Fang Chen ◽  
Xiaosong Hu ◽  
Li Dong

Spores from the Bacillus species pose a challenge to the food industry because of their ubiquitous nature and extreme resistance. Accumulated evidence indicates that it is effective to induce spore germination homogenously before killing them. However, it is difficult to obtain and apply exogenous germination factors, which will affect food composition. Therefore, this study screened endogenous germinants from microorganisms by assessing the effect of Escherichia coli, Bacillus subtilis, Saccharomyces cerevisiae, Lactiplantibacillus plantarum, and Streptococcus thermophilus cultures (cell-free) on B. subtilis spore germination. The results showed that the supernatants from these five microorganisms induced spore germination instead of sediments. Moreover, the supernatants of E. coli, B. subtilis, and S. cerevisiae exhibited higher germination rates than L. plantarum and S. thermophilus, and the induction effects were concentration-dependent. Furthermore, plate counting confirmed that the microbial supernatants induced the lowest spore germination ratio on strains B. subtilis FB85 [germination receptors (GRs) mutant] but not strains B. subtilis PB705 (PrkC mutant). In addition, B. subtilis and S. cerevisiae supernatants, combined with pressure and temperature, were effective in spore inactivation. The findings suggested that microbial supernatants may include agents that induce spore germination and may be used for spore inactivation.

1978 ◽  
Vol 24 (11) ◽  
pp. 1431-1433 ◽  
Author(s):  
William J. Page ◽  
Wendy G. Martin

Air-dried films of Escherichia coli, Saccharomyces cerevisiae, and Bacillus subtilis spores on membrane filters, exposed to 10 min full power (650 W, 2450 MHz) irradiation in a Toshiba model ER776BT microwave oven, showed a 5-, 2-, and 0-log reduction of viable organisms respectively. Suspensions of cells or spores in phosphate buffer treated under similar conditions showed 8 logs of killing within 30 s (S. cerevisiae), 45 s (E. coli), and by 10 min (B. subtilis spores) of exposure.


2008 ◽  
Vol 32 (3) ◽  
pp. 875-881 ◽  
Author(s):  
Lúcia Péret-Almeida ◽  
Cristina da Cunha Naghetini ◽  
Elzíria de Aguiar Nunan ◽  
Roberto Gonçalves Junqueira ◽  
Maria Beatriz Abreu Glória

Este trabalho teve como objetivo avaliar a atividade antimicrobiana da cúrcuma em pó, da curcumina disponível no comércio, dos pigmentos curcuminóides purificados e dos óleos essenciais da cúrcuma. As amostras foram analisadas quanto aos teores de pigmentos curcuminóides por cromatografia líquida de alta eficiência. O óleo essencial foi também analisado quanto à densidade, índice de refração e perfil das substâncias voláteis por cromatografia gasosa e detector de ionização de chamas. A atividade antimicrobiana in vitro foi determinada pelo método de difusão em ágar com discos de papel estéreis, impregnados com os extratos, sendo os diâmetros dos halos de inibição medidos com paquímetro. Os extratos etanólicos da cúrcuma, da curcumina comercial, e dos pigmentos curcumina e desmetoxicurcumina não inibiram o crescimento de Staphylococcus aureus, Bacillus subtilis, Salmonella choleraesuis, Escherichia coli, Aspergillus niger, Saccharomyces cerevisiae, e Candida albicans. Apenas o extrato etanólico da bisdesmetoxicurcumina apresentou atividade antimicrobiana em relação ao B. subtilis. O óleo essencial da cúrcuma apresentou atividade antimicrobiana para o B. subtilis, S. choleraesuis, E. coli, A. niger e S. cerevisiae, sendo que essa atividade aumentou em função do aumento da concentração. Os halos de inibição, obtidos com o óleo essencial, foram significativos, quando comparados aos respectivos antibióticos tradicionais, cloranfenicol e anfotericina, indicando ser o óleo essencial da cúrcuma um agente antimicrobiano em potencial.


2018 ◽  
Vol 8 (2) ◽  
pp. 354-364
Author(s):  
A. N. Irkitova ◽  
A. V. Grebenshchikova ◽  
A. V. Matsyura

<p>An important link in solving the problem of healthy food is the intensification of the livestock, poultry and fish farming, which is possible only in the adoption and rigorous implementation of the concept of rational feeding of animals. In the implementation of this concept required is the application of probiotic preparations. Currently, there is an increased interest in spore probiotics. In many ways, this can be explained by the fact that they use no vegetative forms of the bacilli and their spores. This property provides spore probiotics a number of advantages: they are not whimsical, easily could be selected, cultivated, and dried. Moreover, they are resistant to various factors and could remain viable during a long period. One of the most famous spore microorganisms, which are widely used in agriculture, is <em>Bacillus subtilis</em>. Among the requirements imposed to probiotic microorganisms is mandatory – antagonistic activity to pathogenic and conditional-pathogenic microflora. The article presents the results of the analysis of antagonistic activity of collection strains of <em>B. subtilis</em>, and strains isolated from commercial preparations. We studied the antagonistic activity on agar and liquid nutrient medias to trigger different antagonism mechanisms of <em>B. subtilis</em>. On agar media, we applied three diffusion methods: perpendicular bands, agar blocks, agar wells. We also applied the method of co-incubating the test culture (<em>Escherichia coli</em>) and the antagonist (or its supernatant) in the nutrient broth. Our results demonstrated that all our explored strains of <em>B. subtilis</em> have antimicrobial activity against a wild strain of <em>E. coli</em>, but to varying degrees. We identified strains of <em>B. subtilis</em> with the highest antagonistic effect that can be recommended for inclusion in microbial preparations for agriculture.</p><p><em><br /></em><em></em></p>


2020 ◽  
Vol 15 (6) ◽  
pp. 665-679
Author(s):  
Alok K. Srivastava ◽  
Lokesh K. Pandey

Background: [1, 3, 4]oxadiazolenone core containing chalcones and nucleosides were synthesized by Claisen-Schmidt condensation of a variety of benzaldehyde derivatives, obtained from oxidation of substituted 5-(3/6 substituted-4-Methylphenyl)-1, 3, 4-oxadiazole-2(3H)-one and various substituted acetophenone. The resultant chalcones were coupled with penta-O-acetylglucopyranose followed by deacetylation to get [1, 3, 4] oxadiazolenone core containing chalcones and nucleosides. Various analytical techniques viz IR, NMR, LC-MS and elemental analysis were used to confirm the structure of the synthesised compounds.The compounds were targeted against Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and Aspergillus flavus, Aspergillus niger and Fusarium oxysporum for antifungal activity. Methods: A mixture of Acid hydrazides (3.0 mmol) and N, Nʹ- carbonyl diimidazole (3.3 mmol) in 15 mL of dioxane was refluxed to afford substituted [1, 3, 4]-oxadiazole-2(3H)-one. The resulted [1, 3, 4]- oxadiazole-2(3H)-one (1.42 mmol) was oxidized with Chromyl chloride (1.5 mL) in 20 mL of carbon tetra chloride and condensed with acetophenones (1.42 mmol) to get chalcones 4. The equimolar ratio of obtained chalcones 4 and β -D-1,2,3,4,6- penta-O-acetylglucopyranose in presence of iodine was refluxed to get nucleosides 5. The [1, 3, 4] oxadiazolenone core containing chalcones 4 and nucleosides 5 were tested to determined minimum inhibitory concentration (MIC) value with the experimental procedure of Benson using disc-diffusion method. All compounds were tested at concentration of 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, 0.62 mg/mL, 0.31 mg/mL and 0.15 mg/mL for antifungal activity against three strains of pathogenic fungi Aspergillus flavus (A. flavus), Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum) and for antibacterial activity against Gram-negative bacterium: Escherichia coli (E. coli), and two Gram-positive bacteria: Staphylococcus aureus (S. aureus) and Bacillus subtilis(B. subtilis). Result: The chalcones 4 and nucleosides 5 were screened for antibacterial activity against E. coli, S. aureus and B. subtilis whereas antifungal activity against A. flavus, A. niger and F. oxysporum. Compounds 4a-t showed good antibacterial activity whereas compounds 5a-t containing glucose moiety showed better activity against fungi. The glucose moiety of compounds 5 helps to enter into the cell wall of fungi and control the cell growth. Conclusion: Chalcones 4 and nucleosides 5 incorporating [1, 3, 4] oxadiazolenone core were synthesized and characterized by various spectral techniques and elemental analysis. These compounds were evaluated for their antifungal activity against three fungi; viz. A. flavus, A. niger and F. oxysporum. In addition to this, synthesized compounds were evaluated for their antibacterial activity against gram negative bacteria E. Coli and gram positive bacteria S. aureus, B. subtilis. Compounds 4a-t showed good antibacterial activity whereas 5a-t showed better activity against fungi.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 585
Author(s):  
Marie-Louise Heymich ◽  
Laura Nißl ◽  
Dominik Hahn ◽  
Matthias Noll ◽  
Monika Pischetsrieder

The fight against food waste benefits from novel agents inhibiting spoilage. The present study investigated the preservative potential of the antimicrobial peptides Leg1 (RIKTVTSFDLPALRFLKL) and Leg2 (RIKTVTSFDLPALRWLKL) recently identified in chickpea legumin hydrolysates. Checkerboard assays revealed strong additive antimicrobial effects of Leg1/Leg2 with sodium benzoate against Escherichia coli and Bacillus subtilis with fractional inhibitory concentrations of 0.625 and 0.75. Additionally, Leg1/Leg2 displayed antifungal activity with minimum inhibitory concentrations of 500/250 µM against Saccharomyces cerevisiae and 250/125 µM against Zygosaccharomyces bailii. In contrast, no cytotoxic effects were observed against human Caco-2 cells at concentrations below 2000 µM (Leg1) and 1000 µM (Leg2). Particularly Leg2 showed antioxidative activity by radical scavenging and reducing mechanisms (maximally 91.5/86.3% compared to 91.2/94.7% for the control ascorbic acid). The present results demonstrate that Leg1/Leg2 have the potential to be applied as preservatives protecting food and other products against bacterial, fungal and oxidative spoilage.


2008 ◽  
Vol 190 (18) ◽  
pp. 6048-6059 ◽  
Author(s):  
Carine Robichon ◽  
Glenn F. King ◽  
Nathan W. Goehring ◽  
Jon Beckwith

ABSTRACT Bacterial cell division is mediated by a set of proteins that assemble to form a large multiprotein complex called the divisome. Recent studies in Bacillus subtilis and Escherichia coli indicate that cell division proteins are involved in multiple cooperative binding interactions, thus presenting a technical challenge to the analysis of these interactions. We report here the use of an E. coli artificial septal targeting system for examining the interactions between the B. subtilis cell division proteins DivIB, FtsL, DivIC, and PBP 2B. This technique involves the fusion of one of the proteins (the “bait”) to ZapA, an E. coli protein targeted to mid-cell, and the fusion of a second potentially interacting partner (the “prey”) to green fluorescent protein (GFP). A positive interaction between two test proteins in E. coli leads to septal localization of the GFP fusion construct, which can be detected by fluorescence microscopy. Using this system, we present evidence for two sets of strong protein-protein interactions between B. subtilis divisomal proteins in E. coli, namely, DivIC with FtsL and DivIB with PBP 2B, that are independent of other B. subtilis cell division proteins and that do not disturb the cytokinesis process in the host cell. Our studies based on the coexpression of three or four of these B. subtilis cell division proteins suggest that interactions among these four proteins are not strong enough to allow the formation of a stable four-protein complex in E. coli in contrast to previous suggestions. Finally, our results demonstrate that E. coli artificial septal targeting is an efficient and alternative approach for detecting and characterizing stable protein-protein interactions within multiprotein complexes from other microorganisms. A salient feature of our approach is that it probably only detects the strongest interactions, thus giving an indication of whether some interactions suggested by other techniques may either be considerably weaker or due to false positives.


1993 ◽  
Vol 21 (2) ◽  
pp. 151-155
Author(s):  
Gustaw Kerszman

The toxicity of the first ten MEIC chemicals to Escherichia coli and Bacillus subtilis was examined. Nine of the chemicals were toxic to the bacteria, with the minimal inhibitory concentration (MIC) ranging from 10-3 to 4.4M. The sensitivities of both organisms were similar, but the effect on E. coli was often bactericidal, while it was bacteriostatic for B. subtilis. Digoxin was not detectably toxic to either bacterial species. Amitriptyline and FeSO4 were relatively less toxic to the bacteria than to human cells. For seven chemicals, a highly significant linear regression was established between log MIC in bacteria and log of blood concentration, giving lethal and moderate/mild toxicity in humans, as well as with toxicity to human lymphocytes.


2019 ◽  
Vol 201 (20) ◽  
Author(s):  
Charles T. Lauhon

ABSTRACT In bacteria, tRNAs that decode 4-fold degenerate family codons and have uridine at position 34 of the anticodon are typically modified with either 5-methoxyuridine (mo5U) or 5-methoxycarbonylmethoxyuridine (mcmo5U). These modifications are critical for extended recognition of some codons at the wobble position. Whereas the alkylation steps of these modifications have been described, genes required for the hydroxylation of U34 to give 5-hydroxyuridine (ho5U) remain unknown. Here, a number of genes in Escherichia coli and Bacillus subtilis are identified that are required for wild-type (wt) levels of ho5U. The yrrMNO operon is identified in B. subtilis as important for the biosynthesis of ho5U. Both yrrN and yrrO are homologs to peptidase U32 family genes, which includes the rlhA gene required for ho5C synthesis in E. coli. Deletion of either yrrN or yrrO, or both, gives a 50% reduction in mo5U tRNA levels. In E. coli, yegQ was found to be the only one of four peptidase U32 genes involved in ho5U synthesis. Interestingly, this mutant shows the same 50% reduction in (m)cmo5U as that observed for mo5U in the B. subtilis mutants. By analyzing the genomic context of yegQ homologs, the ferredoxin YfhL is shown to be required for ho5U synthesis in E. coli to the same extent as yegQ. Additional genes required for Fe-S biosynthesis and biosynthesis of prephenate give the same 50% reduction in modification. Together, these data suggest that ho5U biosynthesis in bacteria is similar to that of ho5C, but additional genes and substrates are required for complete modification. IMPORTANCE Modified nucleotides in tRNA serve to optimize both its structure and function for accurate translation of the genetic code. The biosynthesis of these modifications has been fertile ground for uncovering unique biochemistry and metabolism in cells. In this work, genes that are required for a novel anaerobic hydroxylation of uridine at the wobble position of some tRNAs are identified in both Bacillus subtilis and Escherichia coli. These genes code for Fe-S cluster proteins, and their deletion reduces the levels of the hydroxyuridine by 50% in both organisms. Additional genes required for Fe-S cluster and prephenate biosynthesis and a previously described ferredoxin gene all display a similar reduction in hydroxyuridine levels, suggesting that still other genes are required for the modification.


2016 ◽  
Vol 8 (3) ◽  
pp. 333 ◽  
Author(s):  
Abdullahi Aliyu ◽  
Alkali BR ◽  
Yahaya MS ◽  
Garba A ◽  
Adeleye SA ◽  
...  

<p>The aqueous and ethanol extracts of the bark of<em> Khaya senegalensis</em> were screened for their phytochemical constituents and preliminary antibacterial activity against <em>Bacillus subtilis, Escherichia coli</em> and<em> Proteus mirabilis. </em>The minimum inhibitory concentration (MIC) of the plant on the tested organisms was determined using multiple tubes method.</p><p>Alkaloids, anthraquinones, glycosides, tannins and steroids were detected in both extracts.</p><p>The ethanol and aqueous extracts of the plant showed antibacterial activity against <em>B. subtilis and E. coli,</em> with the aqueous extracts having more activity than those of ethanol. However the growth of<em> P. mirabilis</em> was not inhibited by either of the extracts. The MIC value was determined to be 50 mg/ml for<em> B. subtilis </em>and<em> E. coli. </em>The results are suggestive of considerable antibacterial activity of<em> K. senegalensis </em>and may justify its use in the treatment of bacterial diseases by herbalists or traditional healers.</p>


1984 ◽  
Vol 4 (11) ◽  
pp. 2535-2539
Author(s):  
W Y Chooi ◽  
E Otaka

Specific antibodies directed against Drosophila melanogaster acidic ribosomal protein S14 were used in a comparative study of eucaryotic and procaryotic ribosomes by immunoblotting and enzyme-linked immunosorbent assays. Common antigenic determinants and, thus, structural homology were found between D. melanogaster, Saccharomyces cerevisiae (S25), rabbit liver (S12), Bacillus subtilis (S6), and Escherichia coli (S6) ribosomes.


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