**5. Possible mechanisms and management that modulate inhibition of mycotoxin production of** *Fusarium* **species**

Mycotoxins produced by *Fusarium* spp. include different compounds with trichothecenes, fumonisins, zearalenone and emerging toxins such as fusaproliferin, enniatins, beauvericin and moniliformin [10]. This mycotoxins genus can infect cereals directly during ripening, harvesting or storage, the crop soil affecting plant growth and development, which makes its eradication complex and difficult, but various strategies are used to reduce this contamination, butte the best strategies cannot completely eradicate mycotoxin contamination. Prevention strategies during cultivation and storage aim to eliminate mycotoxins; some of the strategies used are crop rotation; in this sense, Schaafsma et al. [59] observed in a 4-year study that planting a crop other than wheat 2 years previous to planting a wheat crop significantly decreased the level of DON in wheat grain in 1 year out of four. This type of studies support the theory that crop residues are the source of *Fusarium* toxin inoculum, so alternating crops would reduce the possibility of contamination. However, studies such as that reported by Fernández-Blanco et al. [25] indicate that wheat grown consecutively (each year) has less contamination by *Fusarium* toxins than alternately grown wheat. Urea fertilization is another strategy to reduce contamination by *Fusarium* sp. as mentioned by Teich [60] and Martin et al. [61], where they applied urea instead of ammonium nitrate, with fewer pollution symptoms observed. Among the aspects to consider in order reducing *Fusarium* contamination is the cultivation season, since it has been documented that winter varieties develop and mature before spring varieties, which reduce the risk of *Fusarium* infection, for avoid that flowering coincides with spore release.

Alternatives to chemical fungicides, such as biocontrol agents, have been tested extensively in both the greenhouse and field environment, but the toxins of *Fusarium* control efficacy under field conditions have not been consistent [62]. However, some of the strategies to reduce contamination at the crop level are not always effective, so at the storage level it is sought to address other types of strategies.

## **5.1. Storage**

The mycotoxins generated by *Fusarium* sp. usually present with greater incidence during the storage. The conditions for the mycotoxins biosynthesis are the grain with temperature 25–32**°**C, moisture between 16 and 30% and air RH of 80 and 100% [63]. This is why the strategies to mitigate and inhibit mycotoxins are postharvest management and storage strategies. Postharvest management has a significant role in mitigation of mycotoxins through good management in grain food chains during harvesting, cleaning, drying, storage and processing. The control of moisture, temperature and humidity to safe storage levels laid a key to mitigate mycotoxins in grains. Ouzounidou et al. [64] indicate that reduction in oxygen and increase in carbon dioxide concentrations generate effects on the growth of fungi. Decreasing O2 to minor of 0.14% and increasing CO2 to more of 50% are required for inhibition of mycelial growth and will prevent mycotoxin [65]. The degree of inhibition achieved by elevated CO2 concentrations is dependent on other environmental factors, such as relative humidity (RH) and temperature [66]. Irradiation is usually used as a mitigation of mycotoxins; 4–6 kGy gamma-irradiation reduces *Fusarium* toxins and was eliminated at 8 kGy [67]. Both inhibition and elimination of *Fusarium* mycotoxins can be attributed to providing energy, which results in reactions and changes molecular structures.

Mycoparasitism is the mechanism by which a fungus parasitized another fungus and is used with biocontrol strategy. Many studies suggested that mycoparasitism was associated with competition for nutrients and space, generation of antibiotic and induction of systemic resistance on *Fusarium* spp. [78–80]. Competition for nutrients and space in the soil is considered to be responsible for the phenomenon of fungistasis via the inhibition of the germination of fungal spores in soil [81]. The deprivation of the resource in the soils is partly responsible for the suppressive nature of soils. When the antagonists present in sufficient quantity at the right time and place and can use nutrients more efficiently than the pathogen, this competition can

*Fusarium* Mycotoxins and Metabolites that Modulate Their Production

http://dx.doi.org/10.5772/intechopen.72874

33

On the other hand, the production of metabolites toxic is another strategy used for the control of diverse strains of *Fusarium*. Dunlap et al. [82] in *B. amyloliquefaciens* AS 43.3 identified nine gene clusters encoding for the biosynthesis of secondary metabolites associated with the biological control of *Fusarium*. The application of gases like ozone is another strategy for the detoxification of mycotoxins; Li et al. [83] obtained a reduction of 57.3% in DON by ozonation, with the moisture content of 17% in wheat. The ozone is a gas, has a favorable penetration and can decompose the double bonds in organisms and further produces simple products with less double bond and low molecular weight; in addition, it can decompose to oxygen voluntarily with non-toxic residual. Other strategie is the application of photocatalytic activity of graphene/Zno hybrids can be useful to degrade DON up to 99% according to Bai et al. [84]. The information on possible mechanism and strategies that can help detoxification of

We want to thank PFCE 2017 economic support for the realization of this research.

, Ramon G. Guevara-Gonzalez<sup>4</sup>

1 Department of Nursing and Obstetrics, Division of Health Sciences and Engineering,

3 Health Sciences Division, University of the Valley of Mexico, Santiago de Querétaro,

4 Biosystems Engineering Group, Division of Graduate Studies, School of Engineering, Universidad Autónoma de Querétaro, Santiago de Querétaro, Querétaro, México

2 Department of Clinical Nursing, Division of Health Sciences and Engineering, University

, Juan F. Garcia-Trejo<sup>4</sup>

,

and Ana A. Feregrino-Perez<sup>4</sup>

\*

, Lina Garcia-Mier<sup>3</sup>

\*Address all correspondence to: feregrino.angge@hotmail.com

University of Guanajuato, Celaya, Guanajuato, México

of Guanajuato, Celaya, Guanajuato, México

be used as an effective biological control.

**Acknowledgements**

Sandra N. Jimenez-Garcia<sup>1</sup>

Xóchitl S. Ramirez-Gomez2

**Author details**

Querétaro, Mexico

mycotoxins has increased, however, the road is still long.

#### **5.2. Chemical and biological control**

Another strategy is the application of chemical control as fungicides; however, this application can sometimes be ineffective and even increase the production of mycotoxins [68, 69]. That is why another alternative is the use of natural products in specific essential oils and antioxidant compounds. In stored cereals, the application of natural preservatives and essential oils generate inhibition on *Fusarium* mycotoxins production is found [46]. On the other hand, the agreement of chemical compounds and natural products can generate a reduction of 90% in deoxynivalenol (DON) (*Fusarium* toxin) as reported by Magan [70] in agreeing BHA (butyl hydroxyl anisole), PP (propyl paraben), resveratrol and cinnamon oil. In relation to the use of natural compounds, a study of phenolic extract of *Spirulina* sp. reported by Pagnussatt et al. [71] indicates that the *Spirulina* LEB-18 extract led to mycelial growth inhibitions that ranged between 50% and 90% in addition, the extract inhibits production of nivalenol (NIV) and deoxynivalenol (DON) in 73%. This may be attributed to the extract composition (main constituents were gallic and caffeic acid). Apparently, these compounds act as fungal stressors when they hamper the energy abstention due to the lower glucose availability [72]. This may trigger the production of secondary metabolites to compensate and limit the apparent competition by the substrate of the medium [73].

Biological control is another strategy in the reduction and incidence of *Fusarium* toxin using living microorganism's whit *Bacillus* spp. [74], *Pseudomonas* spp. [75] and *Streptomyces* spp. [74]. The lactic acid bacteria (LAB) strains have been examined for their potential to detoxify zearalenone (ZEA) that is an estrogenic mycotoxin produced by *Fusarium* [76]. Sangsila et al. [77] showed that these strains of LAB are capable of ZEA detoxification in a range of 29.74–83%, where the strain with the best binding capacity was JM0812 with 83% at an initial concentration of ZEA of 74.7 μg/ml, followed by UM054 and UM055 with 82.78 and 81.69%, respectively.

Mycoparasitism is the mechanism by which a fungus parasitized another fungus and is used with biocontrol strategy. Many studies suggested that mycoparasitism was associated with competition for nutrients and space, generation of antibiotic and induction of systemic resistance on *Fusarium* spp. [78–80]. Competition for nutrients and space in the soil is considered to be responsible for the phenomenon of fungistasis via the inhibition of the germination of fungal spores in soil [81]. The deprivation of the resource in the soils is partly responsible for the suppressive nature of soils. When the antagonists present in sufficient quantity at the right time and place and can use nutrients more efficiently than the pathogen, this competition can be used as an effective biological control.

On the other hand, the production of metabolites toxic is another strategy used for the control of diverse strains of *Fusarium*. Dunlap et al. [82] in *B. amyloliquefaciens* AS 43.3 identified nine gene clusters encoding for the biosynthesis of secondary metabolites associated with the biological control of *Fusarium*. The application of gases like ozone is another strategy for the detoxification of mycotoxins; Li et al. [83] obtained a reduction of 57.3% in DON by ozonation, with the moisture content of 17% in wheat. The ozone is a gas, has a favorable penetration and can decompose the double bonds in organisms and further produces simple products with less double bond and low molecular weight; in addition, it can decompose to oxygen voluntarily with non-toxic residual. Other strategie is the application of photocatalytic activity of graphene/Zno hybrids can be useful to degrade DON up to 99% according to Bai et al. [84]. The information on possible mechanism and strategies that can help detoxification of mycotoxins has increased, however, the road is still long.
