scholarly journals Potential Application of Lactic Acid Bacteria to Reduce Aflatoxin B1 and Fumonisin B1 Occurrence on Corn Kernels and Corn Ears

Toxins ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 21 ◽  
Author(s):  
Tiago de Melo Nazareth ◽  
Carlos Luz ◽  
Raquel Torrijos ◽  
Juan Manuel Quiles ◽  
Fernando Bittencourt Luciano ◽  
...  

Fungal spoilage is an important issue for the food industry, leading to food sensory defects, food waste, economic losses and public health concern through the production of mycotoxins. Concomitantly, the search for safer natural products has gained importance since consumers began to look for less processed and chemically treated foods. In this context, the aim of this study was to evaluate the antifungal and antimycotoxigenic effect of seven strains of Lactobacillus plantarum. Lactic acid bacteria (LAB) were grown on Man Rogosa Sharpe (MRS) broth at 37 °C in anaerobic conditions. After that, the cell-free supernatant (CFS) were recovered to determine its antifungal activity by halo diffusion agar test. In addition, minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) was determined for each L. plantarum CFS by 96-well microplates method. Additionally, CFS was used as a natural biocontrol agent on corn kernels and corn ears contaminated with Aspergillus flavus and Fusarium verticillioides, respectively. The L. plantarum CECT 749 CFS showed the highest antifungal effect against all essayed strains. Moreover, the employment of this CFS in food reduced the mycotoxin production at a percentage ranging from 73.7 to 99.7%. These results suggest that the L. plantarum CECT 749 CFS could be promising for the biocontrol of corn.

2021 ◽  
Vol 8 ◽  
Author(s):  
Ilona Stefańska ◽  
Ewelina Kwiecień ◽  
Katarzyna Jóźwiak-Piasecka ◽  
Monika Garbowska ◽  
Marian Binek ◽  
...  

The spread of resistance to antibiotics is a major health concern worldwide due to the increasing rate of isolation of multidrug resistant pathogens hampering the treatment of infections. The food chain has been recognized as one of the key routes of antibiotic resistant bacteria transmission between animals and humans. Considering that lactic acid bacteria (LAB) could act as a reservoir of transferable antibiotic resistance genes, LAB strains intended to be used as feed additives should be monitored for their safety. Sixty-five LAB strains which might be potentially used as probiotic feed additives or silage inoculants, were assessed for susceptibility to eight clinically relevant antimicrobials by a minimum inhibitory concentration determination. Among antimicrobial resistant strains, a prevalence of selected genes associated with the acquired resistance was investigated. Nineteen LAB strains displayed phenotypic resistance to one antibiotic, and 15 strains were resistant to more than one of the tested antibiotics. The resistance to aminoglycosides and tetracyclines were the most prevalent and were found in 37 and 26% of the studied strains, respectively. Phenotypic resistance to other antimicrobials was found in single strains. Determinants related to resistance phenotypes were detected in 15 strains as follows, the aph(3″)-IIIa gene in 9 strains, the lnu(A) gene in three strains, the str(A)-str(B), erm(B), msr(C), and tet(M) genes in two strains and the tet(K) gene in one strain. The nucleotide sequences of the detected genes revealed homology to the sequences of the transmissible resistance genes found in lactic acid bacteria as well as pathogenic bacteria. Our study highlights that LAB may be a reservoir of antimicrobial resistance determinants, thus, the first and key step in considering the usefulness of LAB strains as feed additives should be an assessment of their antibiotic resistance. This safety criterion should always precede more complex studies, such as an assessment of adaptability of a strain or its beneficial effect on a host. These results would help in the selection of the best LAB strains for use as feed additives. Importantly, presented data can be useful for revising the current microbiological cut-off values within the genus Lactobacillus and Pediococcus.


2016 ◽  
Vol 82 (23) ◽  
pp. 6870-6880 ◽  
Author(s):  
Rosa Guarcello ◽  
Maria De Angelis ◽  
Luca Settanni ◽  
Sabino Formiglio ◽  
Raimondo Gaglio ◽  
...  

ABSTRACTAccumulation of biogenic amines (BAs) in cheese and other foods is a matter of public health concern. The aim of this study was to identify the enzyme activities responsible for BA degradation in lactic acid bacteria which were previously isolated from traditional Sicilian and Apulian cheeses. The selected strains would control the concentration of BAs during cheese manufacture. First, 431 isolates not showing genes encoding the decarboxylases responsible for BA formation were selected using PCR-based methods. Ninety-four out of the 431 isolates degraded BAs (2-phenylethylamine, cadaverine, histamine, putrescine, spermine, spermidine, tyramine, or tryptamine) during cultivation on chemically defined medium. As shown by random amplification of polymorphic DNA-PCR and partial sequencing of the 16S rRNA gene, 78 of the 94 strains wereLactobacillusspecies (Lactobacillus casei,Lb. fermentum,Lb. parabuchneri,Lb. paracasei,Lb. paraplantarum, andLb. rhamnosus),Leuconostocspecies (Leuconostoc lactisandLn. mesenteroides),Pediococcus pentosaceus,Lactococcus lactis,Streptococcusspecies (StreptococcusgallolyticusandS. thermophilus),Enterococcus lactis, andWeissella paramesenteroides. A multicopper oxidase-hydrolyzing BA was purified from the most active strain,Lb. paracaseisubsp.paracaseiCB9CT. The gene encoding the multicopper oxidase was sequenced and was also detected in other amine-degrading strains ofLb. fermentum,Lb. paraplantarum, andP. pentosaceus.Lb. paracaseisubsp.paracaseiCB9CT and another strain (CACIO6CT) of the same species that was able to degrade all the BAs were singly used as adjunct starters for decreasing the concentration of histamine and tyramine in industrial Caciocavallo cheese. The results of this study disclose a feasible strategy for increasing the safety of traditional cheeses while maintaining their typical sensorial traits.IMPORTANCEBecause high concentrations of the potentially toxic biogenic amines may be found in traditional/typical cheeses, the safety of these food items should be improved. Lactic acid bacteria selected for the ability to degrade biogenic amines may be used during cheese making to control the concentrations of biogenic amines.


2021 ◽  
Author(s):  
Li Chen ◽  
Linlin Wang ◽  
Jianke Li ◽  
Guowei Shu

Hypertension has been rising health concern since it takes a major risk for cardiovascular disease. Synthetic antihypertensive drugs, including angiotensin-converting enzyme (ACE) inhibitors, effectively controls the high blood pressure but...


Toxins ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 699
Author(s):  
Jinyang Li ◽  
Wenbo Wang ◽  
Sifan Chen ◽  
Tao Shao ◽  
Xuxiong Tao ◽  
...  

This study was conducted to evaluate the effect of lactic acid bacteria (LAB) on fermentation quality, mycotoxin concentrations, and microbial communities of whole-crop corn silages infested with mycotoxigenic fungi. Cultured spores (106 cfu/mL) of mycotoxigenic Aspergillus flavus and Fusarium graminearum were sprayed (5 mL) on corn forage on 27 July and 10 August 2018. On 21 August 2018, sprayed (FI; 3 plots) and unsprayed (NFI; 3 plots) corn forage were harvested at the 1/2 kernel milk line stage, followed by chopping and ensiling without inoculants (CON), or with Lactobacillus buchneri (LB, 1 × 106 cfu/g FW), Lactobacillus plantarum (LT, 1 × 106 cfu/g FW), or L. buchneri + L. plantarum (BT: both L. buchneri and L. plantarum applied at 0.5 × 106 cfu/g FW). After 90 d of ensiling, FI silages had a higher (p < 0.05) pH value and higher acetic acid (ACA), ethanol, and ammonia nitrogen (ammonia N) concentrations, but lower (p < 0.05) lactic acid (LA) concentrations than NFI silage. The inoculants decreased pH and increased LA concentration and LA/ACA compared with CON. The aflatoxin B1 (AFB1) was only detected in FI fresh corn and silages; ensiling decreased (p < 0.05) AFB1 concentration compared with fresh corn, and LB and BT decreased AFB1 concentration compared with CON. The zearalenone (ZEN), deoxynivalenol (DON), and fumonisin B1 (FB1) concentrations were similar (p < 0.05) for NFI silages, while ZEN concentration in BT was the lowest (p < 0.05) among all FI silages; DON and FB1 concentrations in LB, LT, and BT silages were significantly lower (p < 0.05) than those of CON in FI silages. The fungal infestation increased the bacterial and fungal diversity of silages compared with NFI silages. The FI silages had a higher relative abundance (RA) of Lactobacillus, Weissella, Wickerhamomyces, Pichia, and Epicoccum than the corresponding NFI silages. The RA of Aspergillus and Fusarium markedly decreased after 90 d of ensiling, and the inoculation expanded this trend irrespective of fungal infestation. The Penicillium in FI silages survived after 90 d of ensiling, while the inoculants decreased the RA of Penicillium. Inoculants mitigate the adverse effects of fungal infestation on corn silage quality by changing the bacterial and fungal communities.


2005 ◽  
Vol 68 (10) ◽  
pp. 2095-2099 ◽  
Author(s):  
MDUDUZI P. MOKOENA ◽  
PAUL K. CHELULE ◽  
NCEBA GQALENI

Fusarium species are fungi that infect maize products worldwide and elaborate mycotoxins, which have been associated with cancer. This study was carried out to investigate the potential of lactic acid bacteria fermentation in reducing mycotoxin concentration and toxicity in maize meal products. Maize meal was spiked separately with fumonisin B1 and zearalenone and then allowed to ferment for 4 days. The potential cytotoxicity of the mycotoxin-spiked fermented extracts was also investigated using the SNO human esophageal carcinoma cell line (the SNO cell line was explanted from a cancer patient, S.N., a 62-year-old Zulu man, in July 1972). A significant decrease (P &lt; 0.05) in the concentration of the two mycotoxins was observed, with a 56 to 67% and a 68 to 75% reduction in the third and fourth days, respectively. The two mycotoxins were not detectable in commercially fermented maize meal (amahewu) samples. After fermentation, mycotoxin-spiked maize meal samples containing lactic acid bacteria culture were comparatively less toxic to SNO cells than were samples without lactic acid bacteria. However, this difference in toxicity was not significant (P &gt; 0.05). These results indicate that lactic acid bacteria fermentation can significantly reduce the concentration of mycotoxins in maize. However, such a reduction may not significantly alter the possible toxic effects of such toxins. The exact mechanism of toxin reduction warrants further investigation.


2021 ◽  
Vol 17 (1) ◽  
pp. 1-11
Author(s):  
O.J. Ojobo ◽  
J.O. Ugwuanyi

Palm wine produced traditionally and consumed by many people in the South eastern part of Nigeria is a whitish liquid formed by naturally fermenting the sugary sap from various palm plants. In this study, we evaluated the population of yeast and lactic acid bacteria in palm wine with regards to its ethanol concentration from three communities in Enugu Ezike, Enugu State. We monitored the isolation of microbial population as well as biochemical characteristics of fermenting palm wine samples using culture-dependent and culture-independent methods. The fermentation step was performed within time interval and completed after 48hrs. Its acidity increasedprogressively with the production of lactic and acetic acids by bacteria.During the fermentation, palm wine microbial  numbers (log10 CFU/ml) varied between 1.6 x104 to 7.6 x107 for yeast and 4.5 x 104 to 7.8 x 107 for lactic acid bacteria respectively. Similarly, pH and alcohol level of palm wine samples during the fermentation varied between 3.0 to 5.8 and 0.2 to 5.3 respectively. Statistical analysis revealed that there was no significant difference in both yeast and lactic acid bacteria population at 24hrs. At this time, there was an increased metabolic activity, leading to an increase in ethanol production. At 36-48hrs, there was a slight decrease in both the lactic acid bacteria and the yeast, indicating a reduction in source of carbon.The analysis of the yeast and the lactic acid bacterial population revealed different yeast and bacterial population. Bacteria compete with yeast for nutrients during ethanol  production process, potentially causing economic losses. Therefore, it is important to have a better understanding of the abundance and the change in population of lactic acid bacteria and yeast throughout the bio-ethanol process in order to achieve design a more efficient relationship in lactic acid, yeast and ethanol production processes. Keywords: Bacteria, ethanol, lactic acid, palm wine, yeast


2001 ◽  
Vol 67 (4) ◽  
pp. 1607-1612 ◽  
Author(s):  
Won-Bo Shim ◽  
Charles P. Woloshuk

ABSTRACT Fumonisins are a group of mycotoxins produced in corn kernels by the plant-pathogenic fungus Fusarium verticillioides. A mutant of the fungus, FT536, carrying a disrupted gene namedFCC1 (for Fusarium cyclin C1) resulting in altered fumonisin B1 biosynthesis was generated. FCC1 contains an open reading frame of 1,018 bp, with one intron, and encodes a putative 319-amino-acid polypeptide. This protein is similar to UME3 (also called SRB11 or SSN8), a cyclin C of Saccharomyces cerevisiae, and contains three conserved motifs: a cyclin box, a PEST-rich region, and a destruction box. Also similar to the case for C-type cyclins, FCC1was constitutively expressed during growth. When strain FT536 was grown on corn kernels or on defined minimal medium at pH 6, conidiation was reduced and FUM5, the polyketide synthase gene involved in fumonisin B1 biosynthesis, was not expressed. However, when the mutant was grown on a defined minimal medium at pH 3, conidiation was restored, and the blocks in expression ofFUM5 and fumonisin B1 production were suppressed. Our data suggest that FCC1 plays an important role in signal transduction regulating secondary metabolism (fumonisin biosynthesis) and fungal development (conidiation) inF. verticillioides.


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