In Vitro Aflatoxin B1 Binding by the Cell Wall and (1→3)-β-d-Glucan of Baker's Yeast

2018 ◽  
Vol 81 (4) ◽  
pp. 670-676 ◽  
Author(s):  
MOHAMMAD HADI AAZAMI ◽  
MOHAMMAD HASAN FATHI NASRI ◽  
MOHSEN MOJTAHEDI ◽  
SHAHLA ROUDBAR MOHAMMADI

ABSTRACT The aim of this study was to evaluate the ability of heat-killed baker's yeast (HKBY), the cell wall of baker's yeast (CWBY), and cell wall (1→3)-β-d-glucan of baker's yeast (BGBY) to bind aflatoxin B1 (AFB1) in phosphate-buffered saline (PBS) spiked with 0.5 μg/mL AFB1. Baker's yeast (Saccharomyces cerevisiae) was heat killed by autoclaving at 121°C for 10 min. The cell wall was physically extracted, and (1→3)-β-d-glucan was extracted by a modified method. The concentration of AFB1 was determined by high-performance liquid chromatography after exposure to binders for three contact times, 30 min, 5 h, and 24 h, at room temperature. AFB1 binding by HKBY, CWBY, and BGBY was 6.30 to 46.34%. The lowest binding capacity was found for HKBY with a contact time of 30 min, and the highest binding capacity was found for BGBY with a contact time of 24 h. Among binders, CWBY had the highest binder-AFB1 complex stability during washing with PBS, and the lowest stability was found for HKBY complexes. Results of this study indicated that BGBY was the most effective binder, and more exposure to BGBY removes more AFB1 from PBS.

2016 ◽  
Vol 194 ◽  
pp. 1149-1155 ◽  
Author(s):  
Chema Borchani ◽  
Fabienne Fonteyn ◽  
Guilhem Jamin ◽  
Michel Paquot ◽  
Philippe Thonart ◽  
...  

2014 ◽  
Vol 3 (2) ◽  
pp. 35 ◽  
Author(s):  
Fernanda Bovo ◽  
Larissa Tuanny Franco ◽  
Roice Eliana Rosim ◽  
Carmen Silvia Favaro Trindade ◽  
Carlos Augusto Fernandes de Oliveira

<p>Aflatoxin B<sub>1</sub> (AFB<sub>1</sub>) can cause carcinogenic, mutagenic, teratogenic and immunosuppressive effects in humans and animals. Several lactic acid bacteria species have the ability to bind AFB<sub>1 </sub><em>in vitro</em>, showing a potential application for reducing the bioavailability of AFB<sub>1</sub> in contaminated products. Thus, the aim of this study was to evaluate the capacity of <em>Lactobacillus rhamnosus</em>, non-viable and dried, in removing the AFB<sub>1</sub> from a contaminated medium. <em>L. rhamnosus</em> were cultured in MRS broth, sterilized (121 ºC, 15 min.) to inactivate their metabolism and then dried by spray-drying or freeze-drying (lyophilization). Binding assays using AFB<sub>1</sub> (1.0 µg/ml) and <em>L. rhamnosus</em> cells (1×10<sup>10</sup> cells, in suspension or spray-dried or freeze-dried) were conducted at pH 3.0 and 6.0, room temperature and contact time of 60 min. Quantification of AFB<sub>1</sub> was achieved by high performance liquid chromatography. Scanning electron microscope was also performed in order to analyze the drying effect on the atomized and lyophilized <em>L. rhamnosus</em> cells. For pH 3.0 and 6.0, there were no significant differences between AFB<sub>1</sub> binding efficiency by <em>L. rhamnosus</em> cells in solution (45.9 ± 8.8% and 35.8 ± 7.7%, respectively) or freeze-dried (36.6 ± 7.1% and 27.2 ± 4.0%, respectively). However, the spray-dried cells lost completely the AFB<sub>1</sub> binding capacity during atomization, which damaged the structural and functional properties of the bacterial cell wall. In conclusion, <em>L. rhamnosus</em> retained its AFB<sub>1</sub> binding ability only when its cell wall remained intact as observed in the lyophilization procedure. Lyophilized <em>L. rhamnosus</em> cells therefore can be a practicable alternative for decontamination of food products susceptible to aflatoxin contamination.</p>


Author(s):  
Ida N Jamal ◽  
Reiny A Tumbol ◽  
Remy E.P Mangindaan

Motile Aeromonas Septicaemia disease (MAS) attacking tilapia has increased in recent years as a consequence of intensive aquaculture activities, which led to losses in aquaculture industry. The agent causing MAS disease is Aeromonas hydrophila. The disease can be controlled with the β-glucan. As immunostimulants, β-glucans can also increase resistance in farmed tilapia. Studies on the use of β-glucan extracted from baker's yeast Saccharomyces cerevisiae was intended to evaluate the non-specific immune system of tilapia that were challenged with Aeromonas hydrophila. The method used was an experimental method with a completely randomized design consisting of four treatments with three replicats. The dose of β-glucan used as treatments were 0 mg.kg-1 fish (Control), 5 mg.kg-1 fish (B), 10 mg.kg-1 fish (C) and 20 mg.kg-1 fish (D), each treatment as injected three times at intervals of 3 days, the injection volume of 0.5 ml/fish for nine days and resistance surveillance for seven days. The results showed that the difference in the amount of β-glucan and the frequency of the injected real influence on total leukocytes, phagocytic activity and resistance. Total leukocytes, phagocytic activity and resistance to treatment was best achieved by the administration of C a dose of  10 mg.kg-1 of the fish© Penyakit Motil Aeromonas Septicaemia (MAS) yang menyerang ikan nila mengalami peningkatan selama beberapa tahun terakhir sebagai konsekuensi dari kegiatan akuakultur intensif, yang menyebabkan kerugian dalam industri budidaya. Agen utama penyebab penyakit MAS adalah Aeromonas hydrophila. Untuk mengendalikan penyakit tersebut dapat dilakukan dengan pemberian β-glukan. Sebagai imunostimulan, β-glukan juga dapat  meningkatkan resistensi pada ikan nila yang dibudidayakan. Pengkajian mengenai pemanfaatan β-glukan yang diekstrak dari ragi roti Saccharomyces cerevisiae dimaksudkan untuk menguji sistem imun non spesifik ikan nila yang diuji tantang dengan bakteri Aeromonas hydrophila. Metode yang digunakan yaitu metode eksperimen dengan rancangan acak lengkap yang terdiri dari empat perlakuan dan tiga ulangan. Dosis β-glukan  yang digunakan sebagai perlakuan sebesar 0 mg.kg-1 ikan (Kontrol), 5 mg.kg-1 ikan (B), 10 mg.kg-1 ikan (C) dan 20 mg.kg-1 ikan (D), masing-masing perlakuan diinjeksi sebanyak 3 kali dengan interval waktu 3 hari selama 9 hari, volume injeksi 0,5 mL/ekor ikan dan pengamatan resistensi selama tujuh hari. Hasil penelitian menunjukkan perbedaan jumlah β-glukan dan frekuensi pemberian yang diinjeksikan memberikan pengaruh nyata terhadap total leukosit, aktivitas fagositosis dan resistensi. Total leukosit, aktivitas fagositosis dan resistensi terbaik dicapai pada perlakuan C dengan dosis 10 mg.kg-1 ikan©


2011 ◽  
Vol 1 (1) ◽  
pp. 4 ◽  
Author(s):  
Hansen W. Murcia ◽  
Gonzalo J. Díaz ◽  
Sandra Milena Cepeda

Cytochrome P450 enzymes (CYP) are a group of monooxygenases able to biotransform several kinds of xenobiotics including aflatoxin B1 (AFB1), a highly toxic mycotoxin. These enzymes have been widely studied in humans and others mammals, but there is not enough information in commercial poultry species about their biochemical characteristics or substrate specificity. The aim of the present study was to identify CYPs from avian liver microsomes with the use of prototype substrates specific for human CYP enzymes and AFB1. Biochemical characterization was carried out in vitro and biotransformation products were detected by high-performance liquid chromatography (HPLC). Enzymatic constants were calculated and comparisons between turkey, duck, quail and chicken activities were done. The results demonstrate the presence of four avian ortholog enzyme activities possibly related with a CYP1A1, CYP1A2, CYP2A6 (activity not previously identified) and CYP3A4 poultry orthologs, respectively. Large differences in enzyme kinetics specific for prototype substrates were found among the poultry species studied. Turkey liver microsomes had the highest affinity and catalytic rate for AFB1 whereas chicken enzymes had the lowest affinity and catalytic rate for the same substrate. Quail and duck microsomes showed intermediate values. These results correlate well with the known in vivo sensitivity for AFB1 except for the duck. A high correlation coefficient between 7-ethoxyresorufin-Odeethylase (EROD) and 7-methoxyresorufin- O-deethylase (MROD) activities was found in the four poultry species, suggesting that these two enzymatic activities might be carried out by the same enzyme. The results of the present study indicate that four prototype enzyme activities are present in poultry liver microsomes, possibly related with the presence of three CYP avian orthologs. More studies are needed in order to further characterize these enzymes.


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