scholarly journals Biocontrol of Aspergillus and Fusarium Mycotoxins in Africa: Benefits and Limitations

Toxins ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 109 ◽  
Author(s):  
Victor Kagot ◽  
Sheila Okoth ◽  
Marthe De Boevre ◽  
Sarah De Saeger

Fungal contamination and the consequent mycotoxin production is a hindrance to food and feed safety, international trade and human and animal health. In Africa, fungal contamination by Fusarium and Aspergillus is heightened by tropical climatic conditions that create a suitable environment for pre- and postharvest mycotoxin production. The biocontrol of Fusarium and its associated fusariotoxins has stagnated at laboratory and experimental levels with species of Trichoderma, Bacillus and atoxigenic Fusarium being tested as the most promising candidates. Hitherto, there is no impetus to upscale for field use owing to the inconsistent results of these agents. Non-aflatoxigenic strains of Aspergillus have been developed to create biocontrol formulations by outcompeting the aflatoxigenic strains, thus thwarting aflatoxins on the target produce by 70% to 90%. Questions have been raised on their ability to produce other mycotoxins like cyclopiazonic acid, to potentially exchange genetic material and to become aflatoxigenic with consequent deleterious effects on other organisms and environments. Other biocontrol approaches to mitigate aflatoxins include the use of lactic acid bacteria and yeast species which have demonstrated the ability to prevent the growth of Aspergillus flavus and consequent toxin production under laboratory conditions. Nevertheless, these strategies seem to be ineffective under field conditions. The efficacy of biological agents is normally dependent on environmental factors, formulations’ safety to non-target hosts and the ecological impact. Biocontrol agents can only be effectively evaluated after long-term use, causing a never-ending debate on the use of live organisms as a remedy to pests and diseases over the use of chemicals. Biocontrol should be used in conjunction with good agricultural practices coupled with good postharvest management to significantly reduce mycotoxins in the African continent.

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2064
Author(s):  
Lien Thi Kim Phan ◽  
Trang Minh Tran ◽  
Kris Audenaert ◽  
Liesbeth Jacxsens ◽  
Mia Eeckhout

This study evaluates the influence of crop seasons, cultivation regions, and traditional agricultural practices on the occurrence of F. proliferatum and A. flavus in the rice chain in the Mekong Delta, Vietnam. A survey on pre- and post-harvest practices was performed from 2017 to 2019 in parallel with sampling. Results showed that F. proliferatum (36.3%) and A. flavus (10%) were predominantly present throughout the rice chain. These fungi frequently occurred in winter–spring and autumn–winter crops in Can Tho paddy. Especially, F. proliferatum appeared both on the field and during transportation (50–100%), while A. flavus presented at all stages (10–33%). The occurrence of F. proliferatum reduced 70–27% after drying, depended on the seasons, compared to field and transportation stages and could not be detected anymore at further stages. Applying poor pre-harvest agricultural practices such as the use of certain varieties (Jasmine, DT8 varieties), combination of fertilizers (organic–inorganic), fields with crop debris, unhygienic boats, and delayed drying time of 8–12 h or 12–28 h resulted in an increase in fungal contamination on paddy. This study provides a detailed description of fungi contamination in crop seasons, cultivation regions, and agricultural practices, which may help in understanding the fungal dynamic and allow identification of good agricultural practices to mitigate the fungal contamination and potential mycotoxin production.


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 454
Author(s):  
Magdalena Polak-Śliwińska ◽  
Beata Paszczyk

Trichothecene mycotoxins are sesquiterpenoid compounds primarily produced by fungi in taxonomical genera such as Fusarium, Myrothecium, Stachybotrys, Trichothecium, and others, under specific climatic conditions on a worldwide basis. Fusarium mold is a major plant pathogen and produces a number of trichothecene mycotoxins including deoxynivalenol (or vomitoxin), nivalenol, diacetoxyscirpenol, and T-2 toxin, HT-2 toxin. Monogastrics are sensitive to vomitoxin, while poultry and ruminants appear to be less sensitive to some trichothecenes through microbial metabolism of trichothecenes in the gastrointestinal tract. Trichothecene mycotoxins occur worldwide however both total concentrations and the particular mix of toxins present vary with environmental conditions. Proper agricultural practices such as avoiding late harvests, removing overwintered stubble from fields, and avoiding a corn/wheat rotation that favors Fusarium growth in residue can reduce trichothecene contamination of grains. Due to the vague nature of toxic effects attributed to low concentrations of trichothecenes, a solid link between low level exposure and a specific trichothecene is difficult to establish. Multiple factors, such as nutrition, management, and environmental conditions impact animal health and need to be evaluated with the knowledge of the mycotoxin and concentrations known to cause adverse health effects. Future research evaluating the impact of low-level exposure on livestock may clarify the potential impact on immunity. Trichothecenes are rapidly excreted from animals, and residues in edible tissues, milk, or eggs are likely negligible. In chronic exposures to trichothecenes, once the contaminated feed is removed and exposure stopped, animals generally have an excellent prognosis for recovery. This review shows the occurrence of trichothecenes in food and feed in 2011–2020 and their toxic effects and provides a summary of the discussions on the potential public health concerns specifically related to trichothecenes residues in foods associated with the exposure of farm animals to mycotoxin-contaminated feeds and impact to human health. Moreover, the article discusses the methods of their detection.


Author(s):  
Rohini Mattoo

Abstract Soil bacteria contribute effectively to key biogeochemical reactions in the soil rhizosphere. They support plants in the rhizosphere to adapt quickly to changing climatic conditions. Differences in root exudates, trace gas chemistry, chemical compounds and nutrient exchange contribute to the recruitment of diverse microorganisms by plant roots. This review highlights the importance of characterizing novel microorganisms to support sustainable agricultural practices. We discuss about tools for characterizing microbes and agricultural practices that influence microbial diversity, and have reviewed how microorganisms may have important but unidentified roles in climate change. Beneficial microbes could improve the turnover of carbon, nitrogen, phosphorus and other minerals thereby avoiding the use of chemical inputs, which are not only causing serious environmental harm but also pose danger to human and animal health.


1988 ◽  
Vol 27 (4II) ◽  
pp. 595-604 ◽  
Author(s):  
Eshya Mujahid Mukhtar ◽  
Hanid Mukhtar

Agricultural production depends upon certain crucial inputs e.g., water, fertilizer etc. In the less developed regions of South Asia in general, and the indo-Pakistan sub-continent in particular, the use of these inputs depends not only upon the financial affordability but also upon the institutional accessibility of farmers to these inputs. Besides high economic costs, bureaucratic controls and corruption regarding the distribution of inputs have created problems of limited accessibility, especially to the small farmers. In the absence of any credit, information and/or input distribution networks, the use of these inputs, and related productivity gains, become confined to that class of farmers which not only has better access to these inputs but is capable of using them in the best possible way e.g. use of water and fertilizer in the appropriate amount and at the appropriate time. This paper attempts to study how input use and input productivity vary across farm sizes, with some reference to the infrastructural and institutional factors, whose development play an important role in improving the distribution and productivity of inputs. For such an analysis, a comparison of the two Punjabs i.e. Pakistani and Indian Punjabs, presents an ideal framework, Separated by a national boundary since 1947, the two Punjabs enjoy a common history and culture, similar agricultural practices and agro-climatic conditions, Government policies in the two Punjabs, however, have not only differed between the two provinces at the same time, but also over time in the same province. It may be noted that due to certain policy measures, land distribution, tenancy conditions, promotion of agricultural co-operatives and provision of infrastructural features, such as roads and electricity, are relatively more improved in Indian than Pakistani Punjab.


Soil Systems ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 32
Author(s):  
Haddish Melakeberhan ◽  
Gregory Bonito ◽  
Alexandra N. Kravchenko

Soil health connotes the balance of biological, physicochemical, nutritional, structural, and water-holding components necessary to sustain plant productivity. Despite a substantial knowledge base, achieving sustainable soil health remains a goal because it is difficult to simultaneously: (i) improve soil structure, physicochemistry, water-holding capacity, and nutrient cycling; (ii) suppress pests and diseases while increasing beneficial organisms; and (iii) improve biological functioning leading to improved biomass/crop yield. The objectives of this review are (a) to identify agricultural practices (APs) driving soil health degradations and barriers to developing sustainable soil health, and (b) to describe how the nematode community analyses-based soil food web (SFW) and fertilizer use efficiency (FUE) data visualization models can be used towards developing sustainable soil health. The SFW model considers changes in beneficial nematode population dynamics relative to food and reproduction (enrichment index, EI; y-axis) and resistance to disturbance (structure index, SI; x-axis) in order to identify best-to-worst case scenarios for nutrient cycling and agroecosystem suitability of AP-driven outcomes. The FUE model visualizes associations between beneficial and plant-parasitic nematodes (x-axis) and ecosystem services (e.g., yield or nutrients, y-axis). The x-y relationship identifies best-to-worst case scenarios of the outcomes for sustainability. Both models can serve as platforms towards developing integrated and sustainable soil health management strategies on a location-specific or a one-size-fits-all basis. Future improvements for increased implementation of these models are discussed.


Author(s):  
Jessica A. Rubin ◽  
Josef H. Görres

During this 6th Great Extinction, freshwater quality is imperiled by upland terrestrial practices. Phosphorus, a macronutrient critical for life, can be a concerning contaminant when excessively present in waterways due to its stimulation of algal and cyanobacterial blooms, with consequences for ecosystem functioning, water use, and human and animal health. Landscape patterns from residential, industrial and agricultural practices release phosphorus at alarming rates and concentrations threaten watershed communities. In an effort to reconcile the anthropogenic effects of phosphorus pollution, several strategies are available to land managers. These include source reduction, contamination event prevention and interception. A total of 80% of terrestrial plants host mycorrhizae which facilitate increased phosphorus uptake and thus removal from soil and water. This symbiotic relationship between fungi and plants facilitates a several-fold increase in phosphorus uptake. It is surprising how little this relationship has been encouraged to mitigate phosphorus for water quality improvement. This paper explores how facilitating this symbiosis in different landscape and land-use contexts can help reduce the application of fertility amendments, prevent non-point source leaching and erosion, and intercept remineralized phosphorus before it enters surface water ecosystems. This literature survey offers promising insights into how mycorrhizae can aid ecological restoration to reconcile humans’ damage to Earth’s freshwater. We also identify areas where research is needed.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 327
Author(s):  
Nicolás Verdugo-Vásquez ◽  
Gastón Gutiérrez-Gamboa ◽  
Emilio Villalobos-Soublett ◽  
Andrés Zurita-Silva

In the 90s, as in other countries, transformation of Chilean viticulture brought about the introduction and spread of European grapevine varieties which has resulted in a massive loss of minor local and autochthonous grapevine varieties traditionally grown in several wine growing regions. Fortunately, in recent years, autochthonous and minority varieties have been revalued due to their high tolerance to pests and diseases and because of their adaptation to thermal and water stress triggered by global warming. In this study, we assessed the nutritional status of two autochthonous grapevines grafted onto four different rootstocks under the hyper-arid climatic conditions of Northern Chile over three consecutive seasons. The results showed that R32 rootstock induced high N, P, Ca, Mg and Mn levels in blades compared to Harmony rootstock. R32 rootstock and to a lesser extent, 1103 Paulsen and 140 Ruggeri rootstocks kept balanced levels of nutrients in blades collected from Moscatel Amarilla and Moscatel Negra grapevine varieties. Additionally, Harmony presented slight nutritional imbalance compared to the rest of studied rootstocks due to its low absorption of Mg, Mn, Ca and P, and its high K absorption, which was exacerbated under warm weather and salinity soil conditions. These results may provide a basis for specific cultivar/rootstock/site combinations, a nutritional guide for the viticulturists of Northern Chile, and options to diversify their production favoring the use of minority and autochthonous varieties that adapt well to hyper-arid conditions of Northern Chile.


Conservation ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 21-35
Author(s):  
Kazi Kamrul Islam ◽  
Mohammad Saifullah ◽  
Kimihiko Hyakumura

In the tropics, products and services provided by the traditional agroforestry systems (TAS) support the basic needs and promote the livelihood of millions of rural people. However, the outcomes and mitigation of TAS, in particular, the social and environmental issues are not systematically addressed. Thus, the objective of the study was to assess the economic, social and environmental outcomes of two important TAS in Bangladesh. This study reports results on prospective analyses using the Date palm and Jackfruit-based TAS practiced in the Jashore and Mymensingh districts of Bangladesh. The results revealed that the TAS enhanced farm productivity and the benefit–cost ratio of both systems were much higher than the general agricultural practices in Bangladesh. The TAS also improved resilience of rural farmers through more efficient water utilization, enhancing soil fertility, improving microclimate, controlling pests and diseases, and diversifying products. At the same time, the farmers’ problems were neglected due to the absence of farmers’ platforms, and also tradeoffs may arise; thus, the social aspects of the TAS farmers had not developed equally. Therefore, the study would recommend minimizing the tradeoffs through enhancing the conservation strategies at farmers’ levels to make the TAS more viable and sustainable land-use practices.


Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 214
Author(s):  
Agathe Roucou ◽  
Christophe Bergez ◽  
Benoît Méléard ◽  
Béatrice Orlando

The levels of fumonisins (FUMO)—mycotoxins produced by Fusarium verticillioides—in maize for food and feed are subject to European Union regulations. Compliance with the regulations requires the targeting of, among others, the agroclimatic factors influencing fungal contamination and FUMO production. Arvalis-Institut du végétal has created a national, multiyear database for maize, based on field survey data collected since 2003. This database contains information about agricultural practices, climatic conditions and FUMO concentrations at harvest for 738 maize fields distributed throughout French maize-growing regions. A linear mixed model approach highlights the presence of borers and the use of a late variety, high temperatures in July and October, and a water deficit during the maize cycle as creating conditions favoring maize contamination with Fusarium verticillioides. It is thus possible to target a combination of risk factors, consisting of this climatic sequence associated with agricultural practices of interest. The effects of the various possible agroclimatic combinations can be compared, grouped and classified as promoting very low to high FUMO concentrations, possibly exceeding the regulatory threshold. These findings should facilitate the creation of a national, informative and easy-to-use prevention tool for producers and agricultural cooperatives to manage the sanitary quality of their harvest.


2002 ◽  
Vol 6 (3) ◽  
pp. 497-506 ◽  
Author(s):  
L. Ruiz ◽  
S. Abiven ◽  
P. Durand ◽  
C. Martin ◽  
F. Vertès ◽  
...  

Abstract. The hydrological and biogeochemical monitoring of catchments has become a common approach for studying the effect of the evolution of agricultural practices on water resources. In numerous studies, the catchment is used as a "mega-lysimeter" to calculate annual input-output budgets. However, the literature reflects two opposite interpretations of the trends of nitrate concentration in streamwater. For some authors, essentially in applied studies, the mean residence time of leached nitrate in shallow groundwater systems is much less than one year and river loads reflect annual land use while for others, nitrate is essentially transport limited, independent of soil nitrate supply in the short term and annual variations reflect changes in climatic conditions. This study tests the effect of agricultural land-use changes on inter-annual nitrate trends on stream water of six small adjacent catchments from 0.10 to 0.57 km2 in area, on granite bedrock, at Kerbernez, in Western Brittany (France). Nitrate concentrations and loads in streamwater have been monitored for nine years (1992 to 2000) at the outlet of the catchments. An extensive survey of agricultural practices from 1993 to 1999 allowed assessment of the nitrogen available for leaching through nitrogen budgets. For such small catchments, year-to-year variations of nitrate leaching can be very important, even when considering the 'memory effect' of soil, while nitrate concentrations in streamwater appear relatively steady. No correlation was found between the calculated mean nitrate concentration of drainage water and the mean annual concentration in streams, which can even exhibit opposite trends in inter-annual variations. The climatic conditions do not affect the mean concentration in streamwater significantly. These results suggest that groundwater plays an important role in the control of streamwater nitrate concentration. Keywords: nitrate, diffuse pollution, agricultural catchment, nitrogen budget, leaching, Kerbernez catchments


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