AFLATOXIN G1UPTAKE BY CELLS OF FLAVOBACTERIUM AURANTIACUM

1967 ◽  
Vol 13 (6) ◽  
pp. 629-633 ◽  
Author(s):  
E. B. Lillehoj ◽  
A. Ciegler ◽  
H. H. Hall
Keyword(s):  
Incubation Period ◽  
Culture Media ◽  
Resting Cells ◽  
Liquid Cultures ◽  
Toxin Removal ◽  
Aflatoxin B

Aflatoxin G1was removed from liquid cultures by growing and resting cells of Flavobacterium aurantiacum NRRL B-184. In inoculated culture media containing toxin levels of 7.5 p.p.m. and above, there was a protracted growth lag which was subsequently overcome; toxin removal then occurred, concomitant with growth. Only a few cells demonstrated aberrant morphological forms when cultured in the presence of aflatoxin G1. A comparison of the effects of aflatoxin G1with B1on growth and morphology showed that B1was distinctly more toxic. Three hundred and thirty micrograms of aflatoxin G1was removed per 1 × 1013resting cells during a 4-hour incubation period. Preincubation of resting cells with aflatoxin B1did not interfere with subsequent uptake of G1.

Natural maize phytochemicals for control of maize mycoflora and aflatoxigenic fungi

2009 ◽  
Vol 2 (3) ◽  
pp. 305-312 ◽  
Author(s):  
A. Nesci ◽  
S. Marín ◽  
M. Etcheverry ◽  
V. Sanchis
Keyword(s):  
Ferulic Acid ◽  
Incubation Period ◽  
Cinnamic Acid ◽  
Inhibitory Effect ◽  
Aspergillus Section Flavi ◽  
Aflatoxigenic Fungi ◽  
Incubation Periods ◽  
Maize Grain ◽  
Aflatoxin B ◽  
Aspergillus Section

This research was undertaken to evaluate the effects of the natural phytochemicals trans-cinnamic acid (CA) alone at concentrations of 20 and 25 mM, ferulic acid (FA) at concentration of 30 mM and two mixtures, CA-FA (20+30 mM) and CA-FA (25+30 mM) on natural maize mycoflora, Aspergillus section Flavi population and aflatoxin B1 production. These studies were carried out in maize grain in relation to a water activity of 0.99, 0.97 and 0.94. CA at 25 mM and the mixture CA-FA (25+30 mM) were the most effective treatments at inhibiting natural maize mycoflora at all aw assayed after 11 and 35 days of incubation at 25 °C. In general, 20 mM CA caused complete inhibition of Aspergillus section Flavi population at all aw values tested during all incubation period without an additional inoculum. 20 mM CA and 25 mM CA showed the major inhibitory effect on aflatoxin B1 accumulation of control and Aspergillus section Flavi additionally inoculated during all incubation periods. The data showed that CA and FA could be considered as effective fungitoxicants for natural maize mycoflora and aflatoxigenic fungi in the aw range 0.99 to 0.94. The information obtained shows promise for controlling aflatoxigenic fungi in stored maize.

scholarly journals Cdk5 and GSK3β inhibit Fast Endophilin-Mediated Endocytosis

2020 ◽  
Author(s):  
Antonio P. A. Ferreira ◽  
Alessandra Casamento ◽  
Sara Carrillo Roas ◽  
James Panambalana ◽  
Shaan Subramaniam ◽  
...  
Keyword(s):  
Adrenergic Receptor ◽  
Culture Media ◽  
Growth Factor Receptor ◽  
Surface Proteins ◽  
Serum Starvation ◽  
Resting Cells ◽  
Local Regulation ◽  
Collapsin Response Mediator Protein ◽  
Mediator Protein ◽  
Do So

ABSTRACTEndocytosis mediates the cellular uptake of micronutrients and cell surface proteins. Parallel to Clathrin-mediated endocytosis, additional Clathrin-independent endocytic routes exist, including fast Endophilin-mediated endocytosis (FEME). The latter is not constitutively active but requires the activation of selected receptors. In cell culture, however, the high levels of growth factors in the regular culture media induce spontaneous FEME, which can be suppressed upon serum starvation. Thus, we predicted a role for protein kinases in this growth factor receptor-mediated regulation of the pathway. Using chemical and genetic inhibition, we found that Cdk5 and GSK3β are negative regulators of FEME. Their inhibition was sufficient to activate FEME promptly in resting cells and boosted the production of endocytic carriers containing β 1-adrenergic receptor, following dobutamine addition. We established that the kinases suppress FEME at several levels. They control Dynamin-1 and Dynein recruitment and sorting of cargo receptors such as Plexin A1 and ROBO1 into FEME carriers. They do so by antagonizing the binding of Endophilin to Dynamin-1 as well as to Collapsin response mediator protein 4 (CRMP4), a Plexin A1 adaptor. Cdk5 and GSK3β also hamper the binding and recruitment of Dynein onto FEME carriers by Bin1. Interestingly, we found that GSK3β binds to Endophilin, thus imposing a local regulation of FEME. Collectively, these findings place the two kinases as key regulators of FEME, licensing cells for rapid uptake by the pathway only upon when Cdk5 and GSK3β activity is low.

In vitro effect of Lactobacillus rhamnosus GG on reduction of aflatoxin B1

2014 ◽  
Vol 44 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Parya Rahnama Vosough ◽  
Ali Mohamadi Sani ◽  
Masoumeh Mehraban ◽  
Reza Karazhyan
Keyword(s):  
Binding Capacity ◽  
Lactobacillus Rhamnosus ◽  
Content Type ◽  
Significant Difference ◽  
Toxin Removal ◽  
Viable Bacteria ◽  
Elisa Technique ◽  
Aflatoxin B ◽  
Vitro Effect

Purpose – Since a sound detoxification method is needed for controlling aflatoxin B1 (AFB1), as one of the most harmful mycotoxins in animal production and food industry, this study was performed. The paper aims to discuss these issues. Design/methodology/approach – This study was conducted to examine the ability of Lactobacillus rhamnosus strain GG to remove AFB1 from liquid media. The binding of AFB1 to Lb. rhamnosus GG was studied for viable, heat-killed and acid-killed bacteria. AFB1 at concentrations (5, 10 and 20 μg/l) was added to the bacterial culture (109 cfu/ml) in MRS broth medium and incubated at 25°C for 4, 12 and 24 h. The aflatoxin-binding capacity of the strain was quantified by the amount of unbound AFB1 using ELISA technique. Findings – Results showed the AFB1-binding capacity of viable, heat-killed and acid-killed bacteria was about 43, 49 and 50 percent, respectively. The percentage of AFB1 removed was the highest amount in low (5 μg/l) and high (20 μg/l) concentrations, and there was no significant difference between them (p=0.05). These findings suggest that lactic acid bacteria can be exploited as an approach to detoxification of aflatoxins from foods. Practical implications – This method is safe because non-viable bacteria have more ability to remove toxin than viable bacteria, and also it is an effective method with 50 percent approximately toxin removal. Originality/value – Since there has been no research on the ability of this strain on the removal of AFB1, the authors assessed the ability of the strain in high levels of AFB1.

scholarly journals Factors Affecting the Production of Poly Methyl Galacturonase Enzyme by Sclerotium rolfsii Sacc

2015 ◽  
Vol 3 (1) ◽  
pp. 89-95
Author(s):  
Shridha Chaurasia ◽  
Amit Kumar Chaurasia ◽  
Subha Chaurasia ◽  
Sushmita Chaurasia
Keyword(s):  
Incubation Period ◽  
Culture Media ◽  
Sclerotium Rolfsii ◽  
Culture Conditions ◽  
Experimental Results ◽  
Factors Affecting ◽  
Maximum Production ◽  
Wide Range

The aim of this work was to investigate the effects of different culture conditions on the production of poly methyl galacturonase enzyme bySclerotium rolfsii and their optimization. Activity of poly methyl galacturonase enzyme was assayed by viscometric method. Culture conditionslike culture media, incubation period, temperature and pH greatly influenced the production of poly methyl galacturonase enzyme. Out of tenculture media, only six media were proved to be producer of poly methyl galacturonase enzyme. Amongst them, Elliot’s medium was foundto be the best for the maximum production of poly methyl galacturonase enzyme. Analyzing the different incubation period, the production ofpoly methyl galacturonase enzyme was found rapid (3 days incubation) in Sclerotium rolfsii. Whereas, production of poly methyl galacturonaseenzyme, gradually increased with increasing the length of incubation period up to 18 days and further increase in length of incubation up to 10days, did not show any effect on the production of poly methyl galacturonase. The nine days incubation has found to be the best incubationperiod for the maximum production of poly methyl galacturonase enzyme. The Sclerotium rolfsii was also able to produce the poly methylgalacturonase enzyme at wide range of temperatures (from 15ºC to 35ºC), but 30ºC temperature was found to be the best suitable for themaximum production of poly methyl galacturonase enzyme. Among the wide range of pH tested (pH 3.0 to 9.0), the pH 5.0 was proved to bethe best for the maximum production of poly methyl galacturonase enzyme in Sclerotium rolfsii when it was cultured in the same medium. Onthe basis of overall experimental results it could be concluded that Sclerotium rolfsii has potential to produce poly methyl galacturonase enzymeconstitutively.DOI: http://dx.doi.org/10.3126/ijasbt.v3i1.12200     Int J Appl Sci Biotechnol, Vol. 3(1): 89-95   

Follicle-stimulating hormone–testosterone interaction in modulating steroidogenesis in bovine granulosa cells. I. Effect on progesterone production

1995 ◽  
Vol 132 (6) ◽  
pp. 759-764 ◽  
Author(s):  
Francesca Grasselli ◽  
Giuseppina Basini ◽  
Simona Bussolati ◽  
Carlo Tamanini
Keyword(s):  
Incubation Period ◽  
Granulosa Cells ◽  
Culture Media ◽  
Follicle Stimulating Hormone ◽  
Inhibitory Effect ◽  
Combined Effects ◽  
Dibutyryl Camp ◽  
Progesterone Production ◽  
Camp Formation ◽  
Stimulating Hormone

Grasselli F, Basini G, Bussolati S, Tamanini C. Follicle-stimulating hormone–testosterone interaction in modulating steroidogenesis in bovine granulosa cells. I. Effect on progesterone production. Eur J Endocrinol 1995;132:759–64. ISSN 0804–4643 The aim of this study was to investigate the effects of testosterone on basal and follicle-stimulating hormone (FSH)-induced progesterone production by cultured bovine granulosa cells. Granulosa cells were isolated from small (< 5 mm) and large (>8 mm) follicles and cultured for 48 h in 1 ml of Medium-199 with different concentrations of FSH (0.1, 1, 10 and 35 mg/l). In addition, the combined effects of different amounts of testosterone (1 nmol–10 μmol) and 1 mg/l FSH for 48 h on progesterone production by granulosa cells of both groups of follicles were studied; progesterone production during the subsequent 24-h incubation period was evaluated in the absence of hormones. In a third experiment, granulosa cells were treated with 500 μg of dibutyryl-cAMP and 10 μmol of testosterone for 48 h. At the end of each incubation period, the progesterone content in the culture media was determined by a validated radioimmunoassay. Basal progesterone release during the 48-h incubation period was higher in granulosa cells from small as compared to cells from large follicles; in both groups of cells, progesterone production was stimulated maximally by 1 mg/l FSH. The treatment with 10 μmol of testosterone induced a decrease of progesterone production in both groups of cells, while lower amounts exerted an inhibitory effect only in cells from large follicles. Furthermore, 10 μmol of testosterone inhibited FSH-induced progesterone release, while lower dosages were ineffective. Dibutyryl-cAMP stimulated significantly the progesterone output by granulosa cells of both groups and testosterone was effective in suppressing this increase. Our data demonstrate that testosterone plays an important role in regulating progesterone production by granulosa cells in that it inhibits (at high dosages) both basal and FSH-induced progesterone output. These data also suggest that the site of inhibition is distal to cAMP formation. Carlo Tamanini, Istituto di Fisiologia Veterinaria. Via del Taglio 8, 43100 Parma, Italy

Removal of aflatoxin b1 and t-2 toxin by bacteria isolated from commercially available probiotic dairy foods

2021 ◽  
pp. 108201322098791
Author(s):  
Walter Ondiek ◽  
Yaling Wang ◽  
Lijun Sun ◽  
Langhua Zhou ◽  
Stephen LW On ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Bacterial Cells ◽  
Toxin Concentration ◽  
Dairy Foods ◽  
Heat Treated ◽  
Toxin Removal ◽  
Bacterial Cell Viability ◽  
Aflatoxin B ◽  
Live Bacterial Cells

This study isolated lactic acid bacteria from commercially available probiotic foods to determine their capacity to remove aflatoxin B1 (AFB1) and trichothecene-2 (T-2). The removal rates by original live and heat-treated cells of lactic acid bacteria (LAB) were compared to test the effect of heat treatment on efficacy. LAB is capable to remove up to 46% of AFB1 and up to 45% of T-2 toixn. The toxin removal capability increased as toxin concentration increased despite bacterial cell viability declining. Surprisingly, the denatured LAB removed greater percentages of AFB1 (up to 62%) and T-2 (up to 52%) than live bacterial cells ( P < 0.05), lending support to the hypothesis that there is higher binding of toxins to the cell membrane of nonviable cells. The research provided practical evidences, which suggest that when ingested into the gut biota, LAB could likely reduce absorption of AFB1 and T-2 from contaminated foods.

Accumulation of Volatile Flavour Compounds in Liquid Cultures of Kluyveromyces lactis Strains

1984 ◽  
Vol 39 (11-12) ◽  
pp. 1030-1033 ◽  
Author(s):  
Hans-Peter Hanssen ◽  
Ewald Sprecher ◽  
Andreas Klingenberg
Keyword(s):  
Gas Chromatography ◽  
Culture Medium ◽  
Culture Media ◽  
Kluyveromyces Lactis ◽  
Gas Chromatography Mass Spectrometry ◽  
Nitrogen Compounds ◽  
Liquid Cultures ◽  
Volatile Flavour ◽  
Defined Culture ◽  
Strain Dependent

Abstract The accumulation of volatile flavour constituents in liquid cultures of three Kluyveromyces lactis strains was studied after cultivation on defined culture media containing glucose as carbon source, yeast extract, vitamines, and different additional nitrogen compounds. Besides short-chain alcohols and esters (fruit esters), 2-phenylethyl alcohol, phenylacetaldehyde, and 2-phenylethyl esters could be identified by gas chromatography and coupled gas chromatography-mass spectrometry. Although the composition of these compounds was qualitatively comparable within the three strains investigated, quantitative differences were significant and strain-dependent reactions to the culture medium could be observed.

Studies on the transformation of selected polychlorinated biphenyl congeners by Pseudomonas strain LB 400

1997 ◽  
Vol 43 (8) ◽  
pp. 782-788 ◽  
Author(s):  
K. A. Billingsley ◽  
O. P. Ward ◽  
S. M. Backus
Keyword(s):  
Carbon Source ◽  
Polychlorinated Biphenyls ◽  
Incubation Period ◽  
Polychlorinated Biphenyl ◽  
Carbon Sources ◽  
Lag Phase ◽  
Resting Cells ◽  
Major Objective ◽  
Pcb Congeners ◽  
Degradation Medium

Resting cells of Pseudomonas strain LB400 are known to transform polychlorinated biphenyls (PCBs) when the cells are previously grown on biphenyl. In this study, PCB transformation was also observed in resting cells grown on other substrates such as glucose and glycerol. The presence of PCB congeners in the growth medium increased the lag phase for the growth of cells on a biphenyl substrate but not on a glycerol substrate. Supplementation of the degradation medium with biphenyl dramatically decreased the rate of PCB congener transformation, while the presence of glycerol or glucose had little or no effect on PCB transformation rates. Removal rates with biphenyl-grown cells in the standard degradation medium for 2,4,2′,4′-tetrachlorobiphenyl, 2,4,5,2′,5′-pentachlorobiphenyl, and 2,3-dichlorobiphenyl were 1.06, 1.66, and 224 μmol/(L∙h), respectively. Relative rates of transformation of 2,3-dichlorobiphenyl by biphenyl-, glucose-, and glycerol-grown cells were 100:36:36 and were similar to the relative rates of transformation of 2,4,5,2′,5′-pentachlorobiphenyl (100:33:42). The presence of PCBs adversely affected cell viability of biphenyl-grown cells over a 48-h incubation period and may explain the decline observed in PCB conversion capacity over the same incubation period. A major objective of this study was to investigate the significance of using biphenyl as the carbon source for growth of Pseudomonas strain LB400 cells capable of PCB transformation. Our findings indicate that, whereas higher rates of transformation of PCBs are observed with biphenyl-grown cells, cells grown on other carbon sources retain PCB-transforming enzymes. In addition, it has been demonstrated that biphenyl inhibits transformation of PCBs by the organism, whereas glycerol or glucose does not.Key words: Pseudomonas strain LB400, polychlorinated biphenyls, degradation, biphenyl.

Aflatoxin B 1 degradation by liquid cultures and lysates of three bacterial strains

2016 ◽  
Vol 233 ◽  
pp. 11-19 ◽  
Author(s):  
Oluwafemi Ayodeji Adebo ◽  
Patrick Berka Njobeh ◽  
Sibusiso Sidu ◽  
Matsobane Godfrey Tlou ◽  
Vuyo Mavumengwana
Keyword(s):  
Bacterial Strains ◽  
Liquid Cultures ◽  
Aflatoxin B

scholarly journals Comparison of Four Different Culture Media for Isolation and Growth of Type II and Type I/III Mycobacterium avium subsp. paratuberculosis Strains Isolated from Cattle and Goats

2006 ◽  
Vol 72 (9) ◽  
pp. 5927-5932 ◽  
Author(s):  
Luc�a de Juan ◽  
Julio �lvarez ◽  
Beatriz Romero ◽  
Javier Bezos ◽  
Elena Castellanos ◽  
...  
Keyword(s):  
Incubation Period ◽  
Mycobacterium Avium ◽  
Culture Media ◽  
Egg Yolk ◽  
Disease Diagnosis ◽  
Type I ◽  
Type Ii ◽  
Sodium Pyruvate ◽  
Tissue Samples ◽  
Solid Media

ABSTRACT Culture is considered the definitive technique for Johne's disease diagnosis, and it is essential for later applications of certain molecular typing techniques. In this study, we have tested four solid media (Herrold's egg yolk medium [HEYM] with sodium pyruvate and mycobactin [HEYMm-SP], HEYM with mycobactin and without sodium pyruvate [HEYMm], Middlebrook 7H11 with mycobactin [Mm], and L�wenstein-Jensen with mycobactin [LJm]) for isolation of Mycobacterium avium subsp. paratuberculosis strains in 319 tissue samples from cattle herds and goat flocks. We have shown that each of the two main groups of M. avium subsp. paratuberculosis (type II and type I/III) has different requirements for growth in the culture media studied. The recommended solid media for isolation of type I/III strains are LJm and Mm, since the combination of both media allowed the recovery of all these strains. The most widespread culture medium, HEYM, is not suitable for the isolation of this group of M. avium subsp. paratuberculosis strains. Regarding the type II strains, HEYMm-SP was the medium where more strains were isolated, but the other three media are also needed in order to recover all type II strains. The incubation period is also related to the strain type. In conclusion, because the type of strain cannot be known in advance of culture, coupled with the fact that cattle and goats can be infected with both groups of strains, we recommend the use of the four solid media and the prolongation of the incubation period to more than 6 months to detect paratuberculous herds/flocks and to determine the true prevalence of the infection.

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