4 research outputs found

    Phytopathogenic organisms and mycotoxigenic fungi: Why do we control one and neglect the other? A biological control perspective in Malaysia

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    In this review, we present the current information on development and applications of biological control against phytopathogenic organisms as well as mycotoxigenic fungi in Malaysia as part of the integrated pest management (IPM) programs in a collective effort to achieve food security. Although the biological control of phytopathogenic organisms of economically important crops is well established and widely practiced in Malaysia with considerable success, the same cannot be said for mycotoxigenic fungi. This is surprising because the year round hot and humid Malaysian tropical climate is very conducive for the colonization of mycotoxigenic fungi and the potential contamination with mycotoxins. This suggests that less focus has been made on the control of mycotoxigenic species in the genera Aspergillus, Fusarium, and Penicillium in Malaysia, despite the food security and health implications of exposure to the mycotoxins produced by these species. At present, there is limited research in Malaysia related to biological control of the key mycotoxins, especially aflatoxins, Fusarium‐related mycotoxins, and ochratoxin A, in key food and feed chains. The expected threats of climate change, its impacts on both plant physiology and the proliferation of mycotoxigenic fungi, and the contamination of food and feed commodities with mycotoxins, including the discovery of masked mycotoxins, will pose significant new global challenges that will impact on mycotoxin management strategies in food and feed crops worldwide. Future research, especially in Malaysia, should urgently focus on these challenges to develop IPM strategies that include biological control for minimizing mycotoxins in economically important food and feed chains for the benefit of ensuring food safety and food security under climate change scenario

    Diversity and toxigenicity of mycobiota in grain corn: a case study at pioneer grain corn plantations in Terengganu, Malaysia

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    Malaysia has begun to locally mass-cultivate grain corn to reduce import dependency for animal feed industries. Since the Malaysian tropical climate constantly exposes grain corn to fungal colonization and mycotoxin production by mycotoxigenic species, it is, therefore, important to investigate the presence of fungal species, especially the mycotoxigenic strains in the Malaysian grain corn agroecosystem. In the present work, corn kernel, tassel, plant debris, and soil were collected from two pioneer grain corn farms (Kampong Dadong, KD; Rhu Tapai, RT), and morphological and molecular identifications were conducted. A total of 131 fungal isolates from 30 fungal species were recovered. Both KD and RT yielded log 4.7–6.7 CFU/g total fungal loads. Fusarium verticillioides was predominant in both farms, followed by the phytopathogenic Lasiodiplodia theobromae and the mycotoxigenic Aspergillus flavus, A. niger, F. incarnatum, and F. proliferatum. Mycotoxin analyses by high-performance liquid chromatography revealed that among 30 mycotoxigenic isolates tested for aflatoxins, deoxynivalenol, fumonisins, HT-2, T-2, ochratoxins A, and zearalenone, approximately 25 of the isolates could produce at least one mycotoxin in vitro. The present work serves as a baseline for more comprehensive research to better predict and control fungal contamination and the subsequent mycotoxin accumulation in Malaysian grain corn agroecosystems

    Formulation of maize- and peanut-based semi-synthetic growth media for the ecophysiological studies of aflatoxigenic Aspergillus flavus in maize and peanut agro-ecosystems

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    In studying the ecophysiology of fungal phytopathogens, several stages are involved (in vitro, greenhouse, in planta). Most in vitro studies extensively utilise the general growth media such as Potato Dextrose Agar and Malt Extract Agar. Although the crop components in these media serve as excellent carbon sources and yield luxuriant growth, they are not naturally contaminated with Aspergillus flavus and thus might result in under- or overestimation of its actual toxigenic potentials. Empirical data on the formulation of semi-synthetic growth medium mimicking the natural crop commonly contaminated by A. flavus for the ecophysiological studies in vitro are scarce. The present work was aimed at investigating the ecophysiology of A. flavus on commercial growth media (PDA, MEA); formulating maize- and peanut-based semi-synthetic growth media using two methods of raw material preparation (milling, hot water extraction) at different concentrations (1, 3, 5, 7, 9% w/v), and comparing the ecophysiological parameters between commercial and formulated growth media. Growth rates were obtained by computing the hyphal expansion data into y = mx + c equation. AFB1 was quantified using high performance liquid chromatography with fluorescence detector. Formulated media were found to yield significantly higher growth rates when compared to commercial media. However, commercial media yielded significantly higher AFB1 when compared to all formulated media. Between the two formulations, milling yielded significantly higher growth rates and AFB1 when compared to hot water extraction. Although in vitro data cannot directly extrapolate in planta performance, results obtained in the present work can be used to gauge the actual toxigenic potential of A. flavus in maize and peanut agro-ecosystems

    Does manufacturers' size affect the prevalence of mycobiota and occurrence of mycotoxins in spices and spice-based products?

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    The present work aimed to establish the prevalence of mycobiota and occurrence of mycotoxins (aflatoxins and ochratoxin A) in spices and spice-based products, and correlate these to their manufacturers’ sizes. A total of 90 spice, sauce and paste samples were purchased; 3 manufacturer sizes (small, medium, large) × 3 types of samples (spices, sauces, pastes) × 5 brands × 2 replicates. The prevalence of mycobiota was assessed with dichloran rose bengal chloramphenicol (DRBC) and Aspergillus flavus and Aspergillus parasiticus (AFPA) medium, while the occurrence of mycotoxins was quantified with HPLC-FLD. Large-scale manufacturers were found to adopt a greater number of safety and quality certifications. Small-scale manufacturers significantly yielded the highest total fungal loads on DRBC (log 5.084±0.417 cfu/g paste, log 6.253±0.407 cfu/g sauce, log 6.662±0.222 cfu/g spice) and AFPA (log 4.461±0.451 cfu/g paste, log 5.661±0.395 cfu/g sauce, and log 6.269±0.432 cfu/g spice). Correlation analysis (Pearson’s r) revealed that manufacturers’ sizes positively influenced (DRBC r=0.781; AFPA r=0.702) the prevalence of mycobiota. Aflatoxin B1 was present in 6/30 (20%) paste samples, 1/30 sauce samples (3.33%) and 12/30 spice samples (40%). Aflatoxin B2 was only present in 2/30 sauce samples (6.67%). Aflatoxin G1 and G2 were absent from all samples. Ochratoxin A was present in 11/30 (36.67%) paste samples, 5/30 sauce samples (16.67%) and 21/30 spice samples (70%). It was found that, to a certain extent, the size of and certification adopted by manufacturers affected the prevalence of mycobiota and the occurrence of mycotoxins in spices and spice-based products analysed in the present work. Nevertheless, it is henceforth recommended that a surveillance study of this nature be extended and widened in terms of number of samples as well as type of spices, sauces and pastes to obtain a more thorough and significant profile of the products’ food safety and quality level
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