Metataxonomic analysis of bacterial communities and mycotoxin reduction during processing of three millet varieties into ogi, a fermented cereal beverage

Ihuoma E. Chibuzor-Onyema, Obinna T. Ezeokoli, Michael Sulyok, Iviwe Notununu, Awanwee Petchkongkaew, Christopher T. Elliott, Rasheed A. Adeleke, Rudolf Krska, Chibundu N. Ezekiel*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Ogi is a fermented cereal beverage, made primarily from maize (Zea mays) and rarely from millets. Unlike maize-based ogi, little is known about the bacterial community and mycotoxin profile during the production of millet-based ogi. Therefore, the bacterial community dynamics and mycotoxin reduction during ogi processing from three millet varieties were investigated using next-generation sequencing of the 16S rRNA gene and liquid chromatography-tandem mass spectrometry, respectively. A total of 1163 amplicon sequence variants (ASVs) were obtained, with ASV diversity across time intervals influenced by processing stage and millet variety. ASV distribution among samples suggested that the souring stage was more influenced by millet variety than the steeping stage, and that souring may be crucial for the quality attributes of the ogi. Furthermore, bacterial community structure during steeping and souring was significantly differentiated (PERMANOVA, P < 0.05) between varieties, with close associations observed for closely-related millet varieties. Taxonomically, Firmicutes, followed by Actinobacteria, Bacteroidetes, Cyanobacteria and Proteobacteria phyla were relatively abundant (>1%). Lactic acid bacteria, such as Burkholderia-Caballeronia-Paraburkholderia, Lactobacillus, Lactococcus and Pediococcus, dominated most fermentation stages, suggesting their roles as key fermentative and functional bacteria in relation to mycotoxin reduction. About 52–100%, 58–100% and 100% reductions in mycotoxin (aflatoxins, beauvericin, citrinin, moniliformin, sterigmatocystin and zearalenone) concentrations were recorded after processing of white fonio, brown fonio and finger millet, respectively, into ogi. This study provides new knowledge of the dominant bacterial genera vital for the improvement of millet-based ogi through starter culture development and as well, elucidates the role of processing in reducing mycotoxins in millet ogi.

Original languageEnglish
Article number110241
JournalFood Research International
Volume143
Early online date25 Feb 2021
DOIs
Publication statusPublished - May 2021

Bibliographical note

Funding Information:
This study was supported by the European Union's Horizon 2020 Research and Innovation Program [Grant Agreement No. 692195 (MultiCoop)] and the National Research Foundation of South Africa (Grant Unique Identifier 116251). The authors sincerely appreciate Raimi Adekunle for assisting during the molecular aspect of the study.

Publisher Copyright:
© 2021 Elsevier Ltd

Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.

Keywords

  • Bacterial diversity
  • Beverage
  • Cereals
  • Millet
  • Mycotoxins
  • Ogi

ASJC Scopus subject areas

  • Food Science

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