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Mycotoxins are secondary metabolites of some fungal species and represent important contaminants of food and feed. This study aimed to explore the biological control activity of Bacillus megaterium BM344-1 volatile organic compounds (VOCs) on the growth and mycotoxin production of single representatives of the toxigenic species Aspergillus flavus, Aspergillus carbonarius, Penicillium verrucosum, and Fusarium verticillioides. In vitro co-incubation experiments indicated the P. verrucosum isolate as the most sensitive one, with a growth inhibition ratio of 66.7%, followed by A. flavus (29.4%) and F. verticillioides (18.2%). Exposure of A. flavus, P. verrucosum, and F. verticillioides to BM344-1 VOCs resulted in complete inhibition of aflatoxins (AFB1, AFG1, and AFG2), ochratoxin A, and fumonisin B1 (FB1) synthesis on artificial media, respectively. In vivo experiments on maize kernels showed 51% inhibition of fungal growth on ears simultaneously infected with A. flavus spores and exposed to BM344-1 volatiles. Likewise, AF synthesis by A. flavus was significantly (p < 0.05) inhibited (25.34 ± 6.72 μg/kg) by bacterial volatiles as compared to that in control maize ears (91.81 ± 29.10 μg/kg). Gas chromatography–tandem mass spectrometry-based analysis of headspace volatiles revealed hexadecanoic acid methyl ester (palmitic acid) and tetracosane as bioactive compounds in the BM344-1 volatilome. Bacterial volatiles have promising potential to control the growth and mycotoxin synthesis of toxigenic fungi and may present valuable aid in the efforts to warrant food and feed safety.
Aya Ehab Saleh; Zahoor Ul-Hassan; Randa Zeidan; Noora Al-Shamary; Thoraya Al-Yafei; Hajer Alnaimi; Nayla Salah Higazy; Quirico Migheli; Samir Jaoua. Biocontrol Activity of Bacillus megaterium BM344-1 against Toxigenic Fungi. ACS Omega 2021, 6, 10984 -10990.
AMA StyleAya Ehab Saleh, Zahoor Ul-Hassan, Randa Zeidan, Noora Al-Shamary, Thoraya Al-Yafei, Hajer Alnaimi, Nayla Salah Higazy, Quirico Migheli, Samir Jaoua. Biocontrol Activity of Bacillus megaterium BM344-1 against Toxigenic Fungi. ACS Omega. 2021; 6 (16):10984-10990.
Chicago/Turabian StyleAya Ehab Saleh; Zahoor Ul-Hassan; Randa Zeidan; Noora Al-Shamary; Thoraya Al-Yafei; Hajer Alnaimi; Nayla Salah Higazy; Quirico Migheli; Samir Jaoua. 2021. "Biocontrol Activity of Bacillus megaterium BM344-1 against Toxigenic Fungi." ACS Omega 6, no. 16: 10984-10990.
Along with Aspergillus and Penicillium spp., mycotoxins produced by Fusarium species are important contaminants in food and feed industry. This study was designed to investigate the biodegradation potential of a collection of Bacillus spp. in different substrates artificially contaminated with single or multiple Fusarium mycotoxins. B. megaterium BM344-1 and B. pumilus BP344-3 showed the highest degradation (100%) of zearalenone (ZEN) on liquid Luria Bertani (LB) medium. Bacillus cereus BC344-2, Bacillus cereus BC399-2, Bacillus simplex BS350-3 and Paenibacillus favisporus PF341, showed significant biodegrading capacity on T-2 toxin, leading to 72, 70, 71 and 88% decontamination, respectively. Complete degradation (100%) of ZEN was observed at a contamination level of 0.375 μg/ml in LB, while showing a decreasing trend of degradation (87 and 84%) at increasing levels of mycotoxins (0.750 and 1.50 μg/ml LB medium, respectively). Likewise, BM344-1 showed a decreasing degradation trend (81, 78% and 55%) at increasing T-2 contamination levels (0.3, 0.6 and 1.2 μg/ml, respectively). The ability of BM344-1 to degrade fumonisin B1 (FB1) and fumonisin B2 (FB2) was 14 and 12%, respectively. In LB medium concurrently contaminated with multiple mycotoxins (ZEN+T-2+HT-2+FB1+FB2), the degradation ability of BM344-1 was not affected by low-to-medium levels of each mycotoxin, while it was significantly lowered upon addition of each toxin at higher levels. In vivo mycotoxin degradation potential of BM344-1 tested on artificially contaminated maize showed 25-44% reduction of ZEN and 15-19% reduction of T-2, with a non-significant effect in case of combined mycotoxins contamination. B. megaterium BM344-1, having significant biodegrading properties on multiple Fusarium mycotoxins, can be considered for its potential application as a mycotoxin decontamination agent in the food industry.
Zahoor Ul Hassan; Roda Al Thani; Mohammed Alsafran; Quirico Migheli; Samir Jaoua. Selection of Bacillus spp. with decontamination potential on multiple Fusarium mycotoxins. Food Control 2021, 127, 108119 .
AMA StyleZahoor Ul Hassan, Roda Al Thani, Mohammed Alsafran, Quirico Migheli, Samir Jaoua. Selection of Bacillus spp. with decontamination potential on multiple Fusarium mycotoxins. Food Control. 2021; 127 ():108119.
Chicago/Turabian StyleZahoor Ul Hassan; Roda Al Thani; Mohammed Alsafran; Quirico Migheli; Samir Jaoua. 2021. "Selection of Bacillus spp. with decontamination potential on multiple Fusarium mycotoxins." Food Control 127, no. : 108119.
Mycotoxins, the metabolites of toxigenic fungi are important contaminants of food and agriculture industry throughout the world. Among the different strategies to minimize the mycotoxins synthesis and decontamination of food; yeasts and their derivatives are used as efficient biological control agents. In this study, cell walls (CW) of six yeast strains; two commercial baking {Saccharomyces cerevisiae (Sc 1 and Sc2)}, two low-fermenting (Candida intermedia and Lachancea thermotolerans), and two non-fermenting (Cyberlindnera jadinii and Candida friedrichii) were explored to inhibit A. flavus growth, aflatoxin (AF) synthesis and remove mycotoxins from contaminated buffers (at pH 3, 5 and 7) and milk. The volatiles of non-fermenting yeasts showed a significant inhibitory effect on of A. flavus growth (up to 79%) and aflatoxin synthesis potential. The highest mycotoxins binding activities of Sc strains were noted against ochratoxin A (92%), AFB2 (66%), AFG2 (59%) and AFB1 (31%). The highest and lowest binding activities occurred at pH 7 and pH 3, respectively. On the other hand, all yeast CWs significantly (44%–54%) reduced aflatoxin M1 (AFM1) from contaminated milk. These results show clearly that yeasts (particularly Sc) can be used as efficient biocontrol and decontamination agents in food industry or the management of mycotoxin contamination.
Zahoor Ul Hassan; Roda Al Thani; Fathy A. Atia; Mohammed Alsafran; Quirico Migheli; Samir Jaoua. Application of yeasts and yeast derivatives for the biological control of toxigenic fungi and their toxic metabolites. Environmental Technology & Innovation 2021, 22, 101447 .
AMA StyleZahoor Ul Hassan, Roda Al Thani, Fathy A. Atia, Mohammed Alsafran, Quirico Migheli, Samir Jaoua. Application of yeasts and yeast derivatives for the biological control of toxigenic fungi and their toxic metabolites. Environmental Technology & Innovation. 2021; 22 ():101447.
Chicago/Turabian StyleZahoor Ul Hassan; Roda Al Thani; Fathy A. Atia; Mohammed Alsafran; Quirico Migheli; Samir Jaoua. 2021. "Application of yeasts and yeast derivatives for the biological control of toxigenic fungi and their toxic metabolites." Environmental Technology & Innovation 22, no. : 101447.
Bacillus thuringiensis (Bt) is a Gram-positive soil bacterium that has been recognized as an effective bioinsecticide active against plant, animal and human pathogenic and disease vector insects. During its sporulation phase, Bt produces crystals consisting of δ-endotoxins, which upon ingestion kill specifically insect larvae. Bt subsp. israelensis (Bti) is very active against dipteran insects. Bti based bioinsecticides are considered as a sustainable solution to control the Dipteran insects responsible of plant, animal and human diseases. In this study, Bti strains isolated from Qatar soil were analyzed for their insecticidal activities against the dipteran insect Aedes aegypti Bora Bora (Culicidae, Diptera) and for their δ-endotoxins yields per cell. Among the local Bti strains, four exceptional strains producing spherical crystals, were found to be more insecticidal than the reference strain Bti H14. When tested for their δ-endotoxin yield, the Bti QBT217 strain, producing typical spherical crystals and having the best insecticidal activity, was recognized as the best candidate strain for potential bioinsecticide production and biological control of dipteran insects, particularly the disease vector insect A. aegypti.
Kavita Nair; Roda Al-Thani; Carole Ginibre; Fabrice Chandre; Mohammed Alsafran; Samir Jaoua. Bacillus thuringiensis strains isolated from Qatari soil, synthesizing δ-endotoxins highly active against the disease vector insect Aedes aegypti Bora Bora. Heliyon 2020, 6, e05003 .
AMA StyleKavita Nair, Roda Al-Thani, Carole Ginibre, Fabrice Chandre, Mohammed Alsafran, Samir Jaoua. Bacillus thuringiensis strains isolated from Qatari soil, synthesizing δ-endotoxins highly active against the disease vector insect Aedes aegypti Bora Bora. Heliyon. 2020; 6 (10):e05003.
Chicago/Turabian StyleKavita Nair; Roda Al-Thani; Carole Ginibre; Fabrice Chandre; Mohammed Alsafran; Samir Jaoua. 2020. "Bacillus thuringiensis strains isolated from Qatari soil, synthesizing δ-endotoxins highly active against the disease vector insect Aedes aegypti Bora Bora." Heliyon 6, no. 10: e05003.
This study was designed to investigate the antifungal activity of Bacillus pumilus 344-3 against toxigenic fungi. In vitro co-incubation assay revealed that A. carbonarius AC82, A. niger AN8 and P. digitatum PD43 are most sensitive fungi to bacterial antifungal compounds with zone of inhibition of 29.2 mm, 27.7 mm and 27.1 mm, respectively. The addition of Bacillus pumilus 344-3 culture supernatant at low concentration in the fungal growth medium stimulated A. carbonarius biomass, but inhibited ochratoxin A (OTA) synthesis significantly (p ≤ 0.05). Conidial germination of A. carbonarius was not affected in a medium containing 10% and 20% of the bacterial culture supernatant, while it was completely inhibited in 100% bacterial extract. Storage of bacterial culture supernatant at temperature ranging from −20 °C to 100 °C for 1 h, didn't affect its antifungal potential. In vivo application of bacterial extract on the maize kernels, showed 95% protection against A. carbonarius infection. Application of B. pumilus 344-3 culture supernatant on the surface of maize kernels provided 99% reduction in OTA production potential of A. carbonarius AC82. Because of its strong activities against the growth of A. carbonarius AC82 and OTA-synthesis, B. pumilus 344-3 can be considered as a very promising biocontrol agent.
Nayla Salah Higazy; Aya Ehab Saleh; Zahoor Ul Hassan; Roda Al Thani; Quirico Migheli; Samir Jaoua. Investigation and application of Bacillus pumilus QBP344-3 in the control of Aspergillus carbonarius and ochratoxin A contamination. Food Control 2020, 119, 107464 .
AMA StyleNayla Salah Higazy, Aya Ehab Saleh, Zahoor Ul Hassan, Roda Al Thani, Quirico Migheli, Samir Jaoua. Investigation and application of Bacillus pumilus QBP344-3 in the control of Aspergillus carbonarius and ochratoxin A contamination. Food Control. 2020; 119 ():107464.
Chicago/Turabian StyleNayla Salah Higazy; Aya Ehab Saleh; Zahoor Ul Hassan; Roda Al Thani; Quirico Migheli; Samir Jaoua. 2020. "Investigation and application of Bacillus pumilus QBP344-3 in the control of Aspergillus carbonarius and ochratoxin A contamination." Food Control 119, no. : 107464.
To overcome the economic losses associated with fungi and their toxic metabolites, environmentally safe and efficient approaches are needed. To this end, biological control using yeasts and safe bacterial strains and their products are being explored to replace synthetic fungicides. In the present study, the biocontrol effect of a yeast strain of Kluyveromyces marxianus, QKM-4, against the growth and mycotoxin synthesis potential of key toxigenic fungi was evaluated. In vitro assays were performed to find the application of yeast volatile organic compounds (VOCs) against fungal contamination on important agricultural commodities. The removal of ochratoxin A (OTA) and deoxynivalenol (DON) by living and heat-inactivated yeast cells was also explored. VOCs produced by strain QKM-4 were able to significantly limit the fungal growth of 17 fungal species belonging to genera Aspergillus, Penicillium, and Fusarium. Yeast VOCs were able to reduce OTA biosynthesis potential of Penicillium verrucosum and Aspergillus carbonarius by 99.6 and 98.7%, respectively. In vivo application of QKM-4 VOCs against Fusarium oxysporum and A. carbonarius infection on tomatoes and grapes, respectively, determined a complete inhibition of fungal spore germination. GC/MS-based analysis of yeast VOCs identified long-chain alkanes, including nonadecane, eicosane, docosane, heptacosane, hexatriacontane, and tetracosane. In vitro testing of the mycotoxin-binding potential of the living and heat-inactivated QKM-4 cells showed a reduction of OTA and DON up to 58 and 49%, respectively, from artificially contaminated buffers. Our findings clearly demonstrate the strong antifungal potential of K. marxianus QKM-4 and propose this strain as a strong candidate for application in agriculture to safeguard food and feed products.
Reem Alasmar; Zahoor Ul-Hassan; Randa Zeidan; Roda Al-Thani; Noora Al-Shamary; Hajer Alnaimi; Quirico Migheli; Samir Jaoua. Isolation of a Novel Kluyveromyces marxianus Strain QKM-4 and Evidence of Its Volatilome Production and Binding Potentialities in the Biocontrol of Toxigenic Fungi and Their Mycotoxins. ACS Omega 2020, 5, 17637 -17645.
AMA StyleReem Alasmar, Zahoor Ul-Hassan, Randa Zeidan, Roda Al-Thani, Noora Al-Shamary, Hajer Alnaimi, Quirico Migheli, Samir Jaoua. Isolation of a Novel Kluyveromyces marxianus Strain QKM-4 and Evidence of Its Volatilome Production and Binding Potentialities in the Biocontrol of Toxigenic Fungi and Their Mycotoxins. ACS Omega. 2020; 5 (28):17637-17645.
Chicago/Turabian StyleReem Alasmar; Zahoor Ul-Hassan; Randa Zeidan; Roda Al-Thani; Noora Al-Shamary; Hajer Alnaimi; Quirico Migheli; Samir Jaoua. 2020. "Isolation of a Novel Kluyveromyces marxianus Strain QKM-4 and Evidence of Its Volatilome Production and Binding Potentialities in the Biocontrol of Toxigenic Fungi and Their Mycotoxins." ACS Omega 5, no. 28: 17637-17645.
Studies have demonstrated that microbes facilitate the incorporation of Mg2+ into carbonate minerals, leading to the formation of potential dolomite precursors. Most microbes that are capable of mediating Mg-rich carbonates have been isolated from evaporitic environments in which temperature and salinity are higher than those of average marine environments. However, how such physicochemical factors affect and concur with microbial activity influencing mineral precipitation remains poorly constrained. Here, we report the results of laboratory precipitation experiments using two mineral-forming Virgibacillus strains and one non-mineral-forming strain of Bacillus licheniformis, all isolated from the Dohat Faishakh sabkha in Qatar. They were grown under different combinations of temperature (20°, 30°, 40 °C), salinity (3.5, 7.5, 10 NaCl %w/v), and Mg2+:Ca2+ ratios (1:1, 6:1 and 12:1). Our results show that the incorporation of Mg2+ into the carbonate minerals is significantly affected by all of the three tested factors. With a Mg2+:Ca2+ ratio of 1, no Mg-rich carbonates formed during the experiments. With a Mg2+:Ca2+ ratios of 6 and 12, multivariate analysis indicates that temperature has the highest impact followed by salinity and Mg2+:Ca2+ ratio. The outcome of this study suggests that warm and saline environments are particularly favourable for microbially mediated formation of Mg-rich carbonates and provides new insight for interpreting ancient dolomite formations.
Zulfa Ali Al Disi; Tomaso R. R. Bontognali; Samir Jaoua; Essam Attia; Hamad Al Saad Al-Kuwari; Nabil Zouari. Influence of temperature, salinity and Mg2+:Ca2+ ratio on microbially-mediated formation of Mg-rich carbonates by Virgibacillus strains isolated from a sabkha environment. Scientific Reports 2019, 9, 19633 -12.
AMA StyleZulfa Ali Al Disi, Tomaso R. R. Bontognali, Samir Jaoua, Essam Attia, Hamad Al Saad Al-Kuwari, Nabil Zouari. Influence of temperature, salinity and Mg2+:Ca2+ ratio on microbially-mediated formation of Mg-rich carbonates by Virgibacillus strains isolated from a sabkha environment. Scientific Reports. 2019; 9 (1):19633-12.
Chicago/Turabian StyleZulfa Ali Al Disi; Tomaso R. R. Bontognali; Samir Jaoua; Essam Attia; Hamad Al Saad Al-Kuwari; Nabil Zouari. 2019. "Influence of temperature, salinity and Mg2+:Ca2+ ratio on microbially-mediated formation of Mg-rich carbonates by Virgibacillus strains isolated from a sabkha environment." Scientific Reports 9, no. 1: 19633-12.
Mycotoxins are secondary metabolites produced by certain filamentous fungi, causing human and animal health issues upon the ingestion of contaminated food and feed. Among the safest approaches to the control of mycotoxigenic fungi and mycotoxin detoxification is the application of microbial biocontrol agents. Burkholderia cepacia is known for producing metabolites active against a broad number of pathogenic fungi. In this study, the antifungal potential of a Qatari strain of Burkholderia cepacia (QBC03) was explored. QBC03 exhibited antifungal activity against a wide range of mycotoxigenic, as well as phytopathogenic, fungal genera and species. The QBC03 culture supernatant significantly inhibited the growth of Aspergillus carbonarius, Fusarium culmorum and Penicillium verrucosum in PDA medium, as well as A. carbonarius and P. verrucosum biomass in PDB medium. The QBC03 culture supernatant was found to dramatically reduce the synthesis of ochratoxin A (OTA) by A. carbonarius, in addition to inducing mycelia malformation. The antifungal activity of QBC03’s culture extract was retained following thermal treatment at 100 °C for 30 min. The findings of the present study advocate that QBC03 is a suitable biocontrol agent against toxigenic fungi, due to the inhibitory activity of its thermostable metabolites.
Randa Zeidan; Zahoor Ul-Hassan; Roda Al-Thani; Quirico Migheli; Samir Jaoua. In-Vitro Application of a Qatari Burkholderia cepacia strain (QBC03) in the Biocontrol of Mycotoxigenic Fungi and in the Reduction of Ochratoxin A biosynthesis by Aspergillus carbonarius. Toxins 2019, 11, 700 .
AMA StyleRanda Zeidan, Zahoor Ul-Hassan, Roda Al-Thani, Quirico Migheli, Samir Jaoua. In-Vitro Application of a Qatari Burkholderia cepacia strain (QBC03) in the Biocontrol of Mycotoxigenic Fungi and in the Reduction of Ochratoxin A biosynthesis by Aspergillus carbonarius. Toxins. 2019; 11 (12):700.
Chicago/Turabian StyleRanda Zeidan; Zahoor Ul-Hassan; Roda Al-Thani; Quirico Migheli; Samir Jaoua. 2019. "In-Vitro Application of a Qatari Burkholderia cepacia strain (QBC03) in the Biocontrol of Mycotoxigenic Fungi and in the Reduction of Ochratoxin A biosynthesis by Aspergillus carbonarius." Toxins 11, no. 12: 700.
The present study was designed to investigate the antagonistic activity of Bacillus licheniformis BL350-2 against mycotoxigenic strains of Aspergillus and Penicillium. In vitro coincubation for 5 days indicated Aspergillus westerdijkiae BA1 as the most sensitive strain, with a growth inhibition of 62%, followed by A. carbonarius MG7 (60%), Penicillium verrucosum MC12 (53%), A. niger MC05 (50%), A. flavus CM5 (49%), A. parasiticus SB01 (47%), and A. ochraceus MD1 (44%). Likewise, the majority of the tested strains on exposure to bacterial volatiles showed complete inhibition of mycotoxin synthesis. In vivo assays on maize ears resulted in 88% reduction in A. flavus CM5 growth and complete inhibition of fungal sporulation and aflatoxin accumulation. The GC–MS-based volatile profile showed 3-methyl-1-butanol as the most abundant compound. The findings of the present study advocate that B. licheniformis BL350-2 is suitable as a biocontrol agent against mycotoxigenic fungi, at least during storage of cereal grains.
Zahoor Ul Hassan; Roda Al Thani; Hajer Alnaimi; Quirico Migheli; Samir Jaoua. Investigation and Application of Bacillus licheniformis Volatile Compounds for the Biological Control of Toxigenic Aspergillus and Penicillium spp. ACS Omega 2019, 4, 17186 -17193.
AMA StyleZahoor Ul Hassan, Roda Al Thani, Hajer Alnaimi, Quirico Migheli, Samir Jaoua. Investigation and Application of Bacillus licheniformis Volatile Compounds for the Biological Control of Toxigenic Aspergillus and Penicillium spp. ACS Omega. 2019; 4 (17):17186-17193.
Chicago/Turabian StyleZahoor Ul Hassan; Roda Al Thani; Hajer Alnaimi; Quirico Migheli; Samir Jaoua. 2019. "Investigation and Application of Bacillus licheniformis Volatile Compounds for the Biological Control of Toxigenic Aspergillus and Penicillium spp." ACS Omega 4, no. 17: 17186-17193.
Zulfa Al Disi; Nabil Zouari; Maria Dittrich; Samir Jaoua; Hamad Al Saad Al-Kuwari; Tomaso R.R. Bontognali. Characterization of the extracellular polymeric substances (EPS) of Virgibacillus strains capable of mediating the formation of high Mg-calcite and protodolomite. Marine Chemistry 2019, 216, 1 .
AMA StyleZulfa Al Disi, Nabil Zouari, Maria Dittrich, Samir Jaoua, Hamad Al Saad Al-Kuwari, Tomaso R.R. Bontognali. Characterization of the extracellular polymeric substances (EPS) of Virgibacillus strains capable of mediating the formation of high Mg-calcite and protodolomite. Marine Chemistry. 2019; 216 ():1.
Chicago/Turabian StyleZulfa Al Disi; Nabil Zouari; Maria Dittrich; Samir Jaoua; Hamad Al Saad Al-Kuwari; Tomaso R.R. Bontognali. 2019. "Characterization of the extracellular polymeric substances (EPS) of Virgibacillus strains capable of mediating the formation of high Mg-calcite and protodolomite." Marine Chemistry 216, no. : 1.
The use of yeast-derived volatile organic compounds (VOCs) represents a promising strategy for the biological control of various plant pathogens, including mycotoxin-producing fungi. Previous studies demonstrated the efficacy of the low-fermenting yeast Candida intermedia isolate 253 in reducing growth, sporulation, and ochratoxin A biosynthesis by Aspergillus carbonarius MPVA566. This study aimed to investigate whether the inhibitory effect of the yeast volatilome is solely attributable to 2-phenylethanol, its major component, or if a synergistic effect of all volatilome components is required to achieve an effective control of the fungal growth and metabolism. Microbiological methods, HPLC measurements and a UPLC-MS/MS approach were used to investigate the metabolic profile of A. carbonarius MPVA566 at different growing conditions: standard incubation (control), exposed to C. intermedia 253 volatilome, and incubation in the presence of 2-phenylethanol. Both yeast volatilome and 2-phenylethanol succeeded in the macroscopic inhibition of the radial mycelial growth, along with a significant reduction of ochratoxin A production. Functional classification of the fungal proteome identified in the diverse growing conditions revealed a different impact of both yeast VOCs and 2-phenylethanol exposure on the fungal proteome. Yeast VOCs target an array of metabolic routes of fungal system biology, including a marked reduction in protein biosynthesis, proliferative activity, mitochondrial metabolism, and particularly in detoxification of toxic substances. Exposure to 2-phenylethanol only partially mimicked the metabolic effects observed by the whole yeast volatilome, with protein biosynthesis and proliferative activity being reduced when compared with the control samples, but still far from the VOCs-exposed condition. This study represents the first investigation on the effects of yeast-derived volatilome and 2-phenylethanol on the metabolism of a mycotoxigenic fungus by means of proteomics analysis. 2-Phenylethanol (PubChem CID: 6054); ochratoxin-A (PubChem CID: 442530); sodium dodecyl sulfate (PubChem CID: 3423265); dithiothreitol (PubChem CID: 446094); phenylmethylsulfonyl fluoride (PubChem CID: 4784); iodoacetamide (PubChem CID: 3727); ammonium bicarbonate (PubChem CID: 14013); acetic acid (PubChem CID: 176); and acetonitrile (PubChem CID: 6342).
Bruno Tilocca; Virgilio Balmas; Zahoor Ul Hassan; Samir Jaoua; Quirico Migheli. A proteomic investigation of Aspergillus carbonarius exposed to yeast volatilome or to its major component 2-phenylethanol reveals major shifts in fungal metabolism. International Journal of Food Microbiology 2019, 306, 108265 .
AMA StyleBruno Tilocca, Virgilio Balmas, Zahoor Ul Hassan, Samir Jaoua, Quirico Migheli. A proteomic investigation of Aspergillus carbonarius exposed to yeast volatilome or to its major component 2-phenylethanol reveals major shifts in fungal metabolism. International Journal of Food Microbiology. 2019; 306 ():108265.
Chicago/Turabian StyleBruno Tilocca; Virgilio Balmas; Zahoor Ul Hassan; Samir Jaoua; Quirico Migheli. 2019. "A proteomic investigation of Aspergillus carbonarius exposed to yeast volatilome or to its major component 2-phenylethanol reveals major shifts in fungal metabolism." International Journal of Food Microbiology 306, no. : 108265.
This study aimed to explore the incidence of Fusarium fungi and their mycotoxins in marketed feed in Qatar. Samples of mixed-grain-cereal, maize, wheat, millet, barley, oat and soybean were tested for the presence of zearalenone (ZEN), fumonisins, T2/HT2 and deoxynevalenol (DON) mycotoxins. PCR-based identification of the Fusarium isolates was followed by investigation into genes involved in trichothecenes (tri gene cluster), fumonisins (fum gene cluster) and ZEN (pks gene) biosynthesis. In-vitro mycotoxin production potential of the isolates was compared with their molecular profiles. Mixed-grain cereals showed highest contamination with Fusarium, followed by maize and wheat. The incidence of ZEN was highest in mixed grain samples (87.5%) followed by maize (50%), millet (42.85%) and wheat (40%). In case of DON; 62.5%, 30%, 40%, 14.28%, 50% and 66.67% of the tested mixed cereal grain, maize, wheat, millet, barley and soybean samples were positive. Based on PCR results, F. verticillioides showed highest frequency distribution (34%), followed by F. graminearum (16%), F. oxysporum (15%), F. proliferatum (13%), F. culmorum (8%), F. solani (7%), F. subglutinans (4%) and F. avenaceum (3%) in the feed cereals. All the isolates of F. verticillioides presented both fum1 and fum13 genes, and produced fumonisin mycotoxins in-vitro. All the isolates of F. graminearum and F. culmorum had the tri5 and tri6 genes and resulted in DON accumulation in rice media. In addition to DON, all the F. culmorum isolates produced ZEN in artificially contaminated media, in line with their molecular profile of having tri5, tri6 and pks13 genes. The findings of present study confirmed the occurrence of toxigenic Fusarium and their mycotoxins in animal feed, all below the maximum limit set by EU. Further, the in-vitro mycotoxin production potential of the isolates was in agreement with their tri, fum and pks genetic profiles.
Zahoor Ul Hassan; Roda Al Thani; Virgilio Balmas; Quirico Migheli; Samir Jaoua. Prevalence of Fusarium fungi and their toxins in marketed feed. Food Control 2019, 104, 224 -230.
AMA StyleZahoor Ul Hassan, Roda Al Thani, Virgilio Balmas, Quirico Migheli, Samir Jaoua. Prevalence of Fusarium fungi and their toxins in marketed feed. Food Control. 2019; 104 ():224-230.
Chicago/Turabian StyleZahoor Ul Hassan; Roda Al Thani; Virgilio Balmas; Quirico Migheli; Samir Jaoua. 2019. "Prevalence of Fusarium fungi and their toxins in marketed feed." Food Control 104, no. : 224-230.
Cyt1A98 is a novel cytolytic protein, from BUPM98 Bacillus thuringiensis strain, characterized by its synergistic activity with B. thuringiensis kurstaki toxins against lepidopteran larvae. In this study, we evidenced that Cyt1A98 improves the toxicity of B. thuringiensis kurstaki toxins against A. aegypti larvae. In fact, the strain BNS3pHTcyt1A98 exhibited a larvicidal activity of about 849-fold of that of BNS3pHTBlue against A. aegypti. The molecular and biochemical characterizations, of cyt1A98 gene and its product, were achieved. Cyt1A98 had an LC50 value of about 126.56 mg l−1 against A. aegypti larvae. Compared to Cyt1Aa of B. thuringiensis israelensis, Cyt1A98 amino acid sequence harbours three substitutions of three conserved amino acids among Cyt1Aa family members (Ser42Pro, Pro82Ala, Met188Thr). The Cyt1A98 protein structural analysis evidenced more flexibility than Cyt1Aa. According to the high fluctuation observed for the residue Pro42, the amino acid at position 42 is implicated in the flexibility property of Cyt1Aa especially for the αC and αD helices, involved in the penetration into the cell membrane. The toxicity improvement could be probably due to the higher flexibility combined with the specific affinity toward dipteran larvae. The Cyt1A/B. thuringiensis kurstaki Cry toxins model provides a potential molecular genetic strategy for an efficient bioinsecticide.
Raida Zribi Zghal; Fakher Frikha; Jihen Elleuch; Frédéric Darriet; Fabrice Chandre; Samir Jaoua; Slim Tounsi. The combinatory effect of Cyt1Aa flexibility and specificity against dipteran larvae improves the toxicity of Bacillus thuringensis kurstaki toxins. International Journal of Biological Macromolecules 2018, 123, 42 -49.
AMA StyleRaida Zribi Zghal, Fakher Frikha, Jihen Elleuch, Frédéric Darriet, Fabrice Chandre, Samir Jaoua, Slim Tounsi. The combinatory effect of Cyt1Aa flexibility and specificity against dipteran larvae improves the toxicity of Bacillus thuringensis kurstaki toxins. International Journal of Biological Macromolecules. 2018; 123 ():42-49.
Chicago/Turabian StyleRaida Zribi Zghal; Fakher Frikha; Jihen Elleuch; Frédéric Darriet; Fabrice Chandre; Samir Jaoua; Slim Tounsi. 2018. "The combinatory effect of Cyt1Aa flexibility and specificity against dipteran larvae improves the toxicity of Bacillus thuringensis kurstaki toxins." International Journal of Biological Macromolecules 123, no. : 42-49.
Many foods and beverages in temperate and tropical regions are prone to contamination by ochratoxin A (OTA), one of the most harmful mycotoxins for human and animal health. Aspergillus ochraceus and Aspergillus carbonarius are considered among the main responsible for OTA contamination. We have previously demonstrated that four low or non- fermenting yeasts are able to control the growth and sporulation of OTA-producing Aspergilli both in vitro and on detached grape berries: the biocontrol effect was partly due to the release of volatile organic compounds (VOCs). Aiming to further characterise the effect of VOCs produced by biocontrol yeast strains, we observed that, beside vegetative growth and sporulation, the volatile compounds significantly reduced the production of OTA by two A. carbonarius and A. ochraceus isolates. Exposure to yeast VOCs also affected gene expression in both species, as confirmed by downregulation of polyketide synthase, non-ribosomal peptide synthase, monooxygenase, and the regulatory genes laeA and veA. The main compound of yeast VOCs was 2-phenylethanol, as detected by Headspace-Solid Phase Microextraction-Gas Chromatography-Tandem Mass Spectrometry (HS-SPME-GC–MS) analysis. Yeast VOCs represent a promising tool for the containment of growth and development of mycotoxigenic fungi, and a valuable aid to guarantee food safety and quality.
Maria Grazia Farbo; Pietro Paolo Urgeghe; Stefano Fiori; Angela Marcello; Stefania Oggiano; Virgilio Balmas; Zahoor Ul Hassan; Samir Jaoua; Quirico Migheli. Effect of yeast volatile organic compounds on ochratoxin A-producing Aspergillus carbonarius and A. ochraceus. International Journal of Food Microbiology 2018, 284, 1 -10.
AMA StyleMaria Grazia Farbo, Pietro Paolo Urgeghe, Stefano Fiori, Angela Marcello, Stefania Oggiano, Virgilio Balmas, Zahoor Ul Hassan, Samir Jaoua, Quirico Migheli. Effect of yeast volatile organic compounds on ochratoxin A-producing Aspergillus carbonarius and A. ochraceus. International Journal of Food Microbiology. 2018; 284 ():1-10.
Chicago/Turabian StyleMaria Grazia Farbo; Pietro Paolo Urgeghe; Stefano Fiori; Angela Marcello; Stefania Oggiano; Virgilio Balmas; Zahoor Ul Hassan; Samir Jaoua; Quirico Migheli. 2018. "Effect of yeast volatile organic compounds on ochratoxin A-producing Aspergillus carbonarius and A. ochraceus." International Journal of Food Microbiology 284, no. : 1-10.
This study was designed to explore the incidence of aflatoxin M1 (AFM1) in milk and dairy products marketed in Qatar. Milk (n=72), yogurt (n=21), cheese (n=46), butter (n=18) and laban (n=25) samples were initially screened by competitive enzyme linked immunosorbent assay (ELISA) for the presence of AFM1, followed by confirmation with ultra-high-performance liquid chromatography (UHPLC). AFM1 was detected in 85%, 76%, 85%, 67% and 76% of the milk, yogurt, cheese, butter and laban samples, respectively. The levels of AFM1 in pasteurized vs ultra-high temperature (UHT) milk and full- vs low-fat yogurts showed a non-significant difference. Halloumi and Kashkaval cheese varieties showed a significantly higher AFM1 contents as compared to Mozzarella, Edam, Cheddar, cream and Moshalal cheese. Likewise, unsalted butter demonstrated significantly (p<0.05) higher AFM1 values than salted butter samples. None of the tested samples presented AFM1 levels above the EU maximum limits of 50 ng/L or kg for milk, yogurt and butter, and 250 ng/kg for cheese. From the finding of present study, it can be concluded that, although high percentage of dairy products marketed in Qatar demonstrated AFM1 contents, but do not represent a public health concern considering the EU maximum limits.
Zahoor Ul Hassan; Roda Al-Thani; Fathy A. Atia; Saeed Almeer; Virgilio Balmas; Quirico Migheli; Samir Jaoua. Evidence of low levels of aflatoxin M1 in milk and dairy products marketed in Qatar. Food Control 2018, 92, 25 -29.
AMA StyleZahoor Ul Hassan, Roda Al-Thani, Fathy A. Atia, Saeed Almeer, Virgilio Balmas, Quirico Migheli, Samir Jaoua. Evidence of low levels of aflatoxin M1 in milk and dairy products marketed in Qatar. Food Control. 2018; 92 ():25-29.
Chicago/Turabian StyleZahoor Ul Hassan; Roda Al-Thani; Fathy A. Atia; Saeed Almeer; Virgilio Balmas; Quirico Migheli; Samir Jaoua. 2018. "Evidence of low levels of aflatoxin M1 in milk and dairy products marketed in Qatar." Food Control 92, no. : 25-29.
Mycotoxins are important contaminants of food and feed. In this study, low fermenting yeast (Lachancea thermotolerans) and its derivatives were applied against toxigenic fungi and their mycotoxins. A. parasiticus, P. verrucosum and F. graminearum and their mycotoxins were exposed to yeast volatile organic compounds (VOCs) and cells, respectively. VOCs reduced significantly the fungal growth (up to 48%) and the sporulation and mycotoxin synthesis (up to 96%). Very interestingly, it was shown that even 7 yeast colonies reduced Fusarium’s growth and the synthesis of its mycotoxin, deoxynivalenol (DON). Moreover, decreasing yeast nutrient concentrations did not affect the inhibition of fungal growth, but reduced DON synthesis. In addition, inactivated yeast cells were able to remove up to 82% of the ochratoxin A (OTA). As an application of these findings, the potentialities of the VOCs to protect tomatoes inoculated with F. oxysporum was explored and showed that while in the presence of VOCs, no growth was observed of F. oxysporum on the inoculated surface areas of tomatoes, in the absence of VOCs, F. oxysporum infection reached up to 76% of the tomatoes’ surface areas. These results demonstrate that the application of yeasts and their derivatives in the agriculture and food industry might be considered as a very promising and safe biocontrol approach for food contamination.
Randa Zeidan; Zahoor Ul Hassan; Roda Al-Thani; Virgilio Balmas; Samir Jaoua. Application of Low-Fermenting Yeast Lachancea thermotolerans for the Control of Toxigenic Fungi Aspergillus parasiticus, Penicillium verrucosum and Fusarium graminearum and Their Mycotoxins. Toxins 2018, 10, 242 .
AMA StyleRanda Zeidan, Zahoor Ul Hassan, Roda Al-Thani, Virgilio Balmas, Samir Jaoua. Application of Low-Fermenting Yeast Lachancea thermotolerans for the Control of Toxigenic Fungi Aspergillus parasiticus, Penicillium verrucosum and Fusarium graminearum and Their Mycotoxins. Toxins. 2018; 10 (6):242.
Chicago/Turabian StyleRanda Zeidan; Zahoor Ul Hassan; Roda Al-Thani; Virgilio Balmas; Samir Jaoua. 2018. "Application of Low-Fermenting Yeast Lachancea thermotolerans for the Control of Toxigenic Fungi Aspergillus parasiticus, Penicillium verrucosum and Fusarium graminearum and Their Mycotoxins." Toxins 10, no. 6: 242.
The present study was conducted to explore the occurrence of mycotoxins in commercial baby foods in Doha-Qatar. LCMS/MS- and HPLC-based analysis of baby food (n = 67) for 12 mycotoxins confirmed the presence of aflatoxin M1 (AFM1, 33%), ochratoxin A (OTA, 31%), deoxynivalenol (DON, 27%), aflatoxin B1 (AFB1, 22%), fumonisin B2 (FB2, 10%), zearalenone (ZEN, 4%) and T-2 toxin (2%). Noodles exhibited the maximum contamination percentage, with 33% of the samples being contaminated above the EU maximum limits, for at least one mycotoxin. Among the multi-grain flake samples, up to 28% and for the milk and milk-based-cereal samples, 14% contained at least one mycotoxin above the EU maximum limits. From all cereal-based food samples, 22%, 5%, 2% and 2% were concurrently contaminated with 2, 3, 4 and 5 mycotoxins, respectively. The occurrence of toxicological important mycotoxins in Qatari market warrants the implementation of strict regulatory limits to protect human health.
Zahoor Ul Hassan; Roda Al Thani; Fathy A. Atia; Saeed Al Meer; Quirico Migheli; Samir Jaoua. Co-occurrence of mycotoxins in commercial formula milk and cereal-based baby food on the Qatar market. Food Additives & Contaminants: Part B 2018, 11, 191 -197.
AMA StyleZahoor Ul Hassan, Roda Al Thani, Fathy A. Atia, Saeed Al Meer, Quirico Migheli, Samir Jaoua. Co-occurrence of mycotoxins in commercial formula milk and cereal-based baby food on the Qatar market. Food Additives & Contaminants: Part B. 2018; 11 (3):191-197.
Chicago/Turabian StyleZahoor Ul Hassan; Roda Al Thani; Fathy A. Atia; Saeed Al Meer; Quirico Migheli; Samir Jaoua. 2018. "Co-occurrence of mycotoxins in commercial formula milk and cereal-based baby food on the Qatar market." Food Additives & Contaminants: Part B 11, no. 3: 191-197.
Bacillus thuringiensis (Bt) based insecticidal formulations have been recognized as one of the most successful, environmentally safe and sustainable method of controlling insect pests. Research teams worldwide are in search of Bt diversity giving more choices of bio-insecticides and alternatives to address insect resistance. In fact, there are many unexplored ecologies that could harbor novel Bt strains. This study is the first initiative to explore Bt strain diversity in Qatar. A collection of 700 Bt isolates was constructed. Scanning electron microscopy of Bt crystals showed different crystal forms, with a high abundance of spherical crystals compared to the bipyramidal ones. Among the spherical crystals, four different morphologies were observed. The δ-endotoxin content of parasporal crystals from each Bt isolate revealed that there are 16 different protein profiles among the isolates of the collection. On the other hand, plasmid pattern analysis showed seven different plasmid profiles. Their insecticidal activity was predicted by exploring the δ-endotoxin coding genes and conducting qualitative insecticidal bioassays. 19 smooth spherical crystal producing isolates have been identified that could be possible candidates for endotoxin production targeting Dipteran insects. Another group of 259 isolates producing bipyramidal and cuboidal crystals could target Lepidopteran and Coleopteran insects. The remaining 422 isolates have novel profiles. In conclusion, Qatari soil ecology provides a good collection and diversity of Bt isolates. In addition to strains harboring genes encoding common endotoxins, the majority are different and very promising for the search of novel insecticidal endotoxins.
Kavita Nair; Roda Al-Thani; Dhabia Al-Thani; Fatima Al-Yafei; Talaat Ahmed; Samir Jaoua. Diversity of Bacillus thuringiensis Strains From Qatar as Shown by Crystal Morphology, δ-Endotoxins and Cry Gene Content. Frontiers in Microbiology 2018, 9, 708 .
AMA StyleKavita Nair, Roda Al-Thani, Dhabia Al-Thani, Fatima Al-Yafei, Talaat Ahmed, Samir Jaoua. Diversity of Bacillus thuringiensis Strains From Qatar as Shown by Crystal Morphology, δ-Endotoxins and Cry Gene Content. Frontiers in Microbiology. 2018; 9 ():708.
Chicago/Turabian StyleKavita Nair; Roda Al-Thani; Dhabia Al-Thani; Fatima Al-Yafei; Talaat Ahmed; Samir Jaoua. 2018. "Diversity of Bacillus thuringiensis Strains From Qatar as Shown by Crystal Morphology, δ-Endotoxins and Cry Gene Content." Frontiers in Microbiology 9, no. : 708.
Interference rejection in amperometric biosensors can be more effective introducing some modifiers during electro-deposition of permselective film. Addition of β-cyclodextrin (βCD), a cyclic oligosaccharide composed of seven glucose units, to the ortho-phenylendiamine (oPD) monomer were already demonstrated to provide an enhancement in ascorbic acid (AA) rejection. Here we evaluated the improvement in permselectivity of poly-eugenol and poly-magnolol films electro-polymerized in presence of different amounts of βCD or eugenol-βCD inclusion complex for amperometric biosensor application. Starting from Pt-Ir wire as transducer several microsensors were covered with polymeric films doped with βCD-based modifiers through constant potential amperometry. Characterization of modified polymers was achieved by scanning electron microscopy and permselectivity analysis. Poly-magnolol film in combination with βCD showed a worsening in permselectivity compared to poly-magnolol alone. In contrast, the introduction of βCD-based modifier enhanced the interference rejection toward the archetypal interferent AA, while slightly affecting permeability toward H2O2 compared to the poly-eugenol without modifier. The AA rejection seems to be influenced by the availability of βCD cavity as well as film performance due to concentration of βCD-Eugenol inclusion complex. A poly-eugenol film co-polymerized with 2 mM βCD-eugenol inclusion complex showed a permselectivity equal to poly-orthophenylendiamine film (PPD), with a lower permeability to AA, likely to be related with a self-blocking mechanism. Based on these results, a biosensor for glutamate was constructed with a poly-eugenol doped with βCD-eugenol as permselective layer and its permselectivity, stability and lifetime were determined.
Patrizia Monti; Gaia Rocchitta; Salvatore Marceddu; Maria A. Dettori; Davide Fabbri; Samir Jaoua; Quirico Migheli; Giovanna Delogu; Pier A. Serra. Use of β-cyclodextrin as enhancer of ascorbic acid rejection in permselective films for amperometric biosensor applications. Talanta 2018, 186, 53 -59.
AMA StylePatrizia Monti, Gaia Rocchitta, Salvatore Marceddu, Maria A. Dettori, Davide Fabbri, Samir Jaoua, Quirico Migheli, Giovanna Delogu, Pier A. Serra. Use of β-cyclodextrin as enhancer of ascorbic acid rejection in permselective films for amperometric biosensor applications. Talanta. 2018; 186 ():53-59.
Chicago/Turabian StylePatrizia Monti; Gaia Rocchitta; Salvatore Marceddu; Maria A. Dettori; Davide Fabbri; Samir Jaoua; Quirico Migheli; Giovanna Delogu; Pier A. Serra. 2018. "Use of β-cyclodextrin as enhancer of ascorbic acid rejection in permselective films for amperometric biosensor applications." Talanta 186, no. : 53-59.
Cyt1A protein is a cytolytic protein encoded by the cyt gene of Bacillus thuringiensis subsp. israelensis (Bti) as part of the parasporal crystal proteins produced during the sporulation. Cyt1A protein is unique compared to the other endotoxins present in these parasporal crystals. Unlike δ-endotoxins, Cyt1A protein does not require receptors to bind to the target cell and activate the toxicity. It has the ability to affect a broad range of cell types and organisms, due to this characteristic. Cyt1A has been recognized to not only target the insect cells directly, but also recruit other endotoxins by acting as receptors. Due to these mode of actions, Cyt1A has been studied for its cytolytic activity against human cancer cell lines, although not extensively. In this study, we report a novel Cyt1A protein produced by a Bti strain QBT229 isolated from Qatar. When tested for its cytotoxicity against lung cancer cells, this local strain showed considerably higher activity compared to that of the reference Bti and other strains tested. The possible reasons for such enhanced activity were explored at the gene and protein levels. It was evidenced that five consecutive amino acid replacements in the β8 sheet of the Cyt1A protein enhanced the cytotoxicity against the lung epithelial cancer cells. Such novel Cyt1A protein with high cytotoxicity against lung cancer cells has been characterized and reported through this study.
Kavita Nair; Ahmad Iskandarani; Roda Al-Thani; Ramzi Mohammad; Samir Jaoua. The Replacement of five Consecutive Amino Acids in the Cyt1A Protein of Bacillus thuringiensis Enhances its Cytotoxic Activity against Lung Epithelial Cancer Cells. Toxins 2018, 10, 125 .
AMA StyleKavita Nair, Ahmad Iskandarani, Roda Al-Thani, Ramzi Mohammad, Samir Jaoua. The Replacement of five Consecutive Amino Acids in the Cyt1A Protein of Bacillus thuringiensis Enhances its Cytotoxic Activity against Lung Epithelial Cancer Cells. Toxins. 2018; 10 (3):125.
Chicago/Turabian StyleKavita Nair; Ahmad Iskandarani; Roda Al-Thani; Ramzi Mohammad; Samir Jaoua. 2018. "The Replacement of five Consecutive Amino Acids in the Cyt1A Protein of Bacillus thuringiensis Enhances its Cytotoxic Activity against Lung Epithelial Cancer Cells." Toxins 10, no. 3: 125.