Wild rice (O. latifolia) from natural ecosystems in the Pantanal region of Brazil: Host to Fusarium incarnatum-equiseti species complex and highly contaminated by zearalenone

Author(s)

Tralamazza, Sabina Moser ^[1] ; Piacentini, Karim Cristina ^[1] ; Savi, Geovana Dagostim ^[2] ; Carnielli-Queiroz, Lorena ^[1] ; Fontes, Livia de Carvalho ^[1] ; Martins, Camila Siedlarczyk ^[3] ; Correa, Benedito ^[1] ; Rocha, Liliana Oliveira ^[3]

Affiliation

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Microbiol, Sao Paulo - Brazil

^[2] Univ Southern Santa Catarina UNESC, Sci & Technol Pk, Criciuma, SC - Brazil

^[3] Univ Estadual Campinas, Food Engn Fac, Dept Food Sci, Campinas - Brazil

• Document type: Journal article
• Source: International Journal of Food Microbiology; v. 345, MAY 2 2021.
• Web of Science Citations: 0

Abstract

We assessed the mycobiota diversity and mycotoxin levels present in wild rice (Oryza latifolia) from the Pantanal region of Brazil; fundamental aspects of which are severely understudied as an edible plant from a natural ecosystem. We found multiple fungal species contaminating the rice samples; the most frequent genera being Fusarium, Nigrospora and Cladosporium (35.9%, 26.1% and 15%, respectively). Within the Fusarium genus, the wild rice samples were mostly contaminated by the Fusarium incarnatum-equiseti species complex (FIESC) (80%) along with Fusarium fujikuroi species complex (20%). Phylogenetic analysis supported multiple FIESC species and gave support to the presence of two putative new groups within the complex (LN1 and LN2). Deoxynivalenol (DON) and zearalenone (ZEN) chemical analysis showed that most of the isolates were DON/ZEN producers and some were defined as high ZEN producers, displaying abundant ZEN levels over DON (over 19 times more). Suggesting that ZEN likely has a key adaptive role for FIESC in wild rice (O. latifolia). Mycotoxin determination in the rice samples revealed high frequency of ZEN, and 85% of rice samples had levels >100 ?g/kg; the recommended limit set by regulatory agencies. DON was only detected in 5.2% of the samples. Our data shows that FIESC species are the main source of ZEN contamination in wild rice and the excessive levels of ZEN found in the rice samples raises considerable safety concerns regarding wild rice consumption by humans and animals. (AU)

• FAPESP's process: 16/04364-5 - Diversity of Fusarium graminearum Species Complex isolated from wheat and native grasses of Brazil.
• Grantee: Benedito Corrêa
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/04811-4 - Population structure of the Fusarium graminearum species complex and mycotoxin contamination of cultivated and native barley in Brazil
• Grantee: Liliana de Oliveira Rocha
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 15/21378-7 - Identification and toxigenic profile of Fusarium graminearum species complex by infrared spectroscopy
• Grantee: Sabina Moser Tralamazza
• Support Opportunities: Scholarships in Brazil - Post-Doctoral