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

doi:10.1016/j.foodres.2021.110241

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

Food Res Int. 2021 May:143:110241. doi: 10.1016/j.foodres.2021.110241. Epub 2021 Feb 25.

Authors

Ihuoma E Chibuzor-Onyema¹, Obinna T Ezeokoli², Michael Sulyok³, Iviwe Notununu⁴, Awanwee Petchkongkaew⁵, Christopher T Elliott⁶, Rasheed A Adeleke⁷, Rudolf Krska⁸, Chibundu N Ezekiel⁹

Affiliations

¹ Department of Microbiology, Babcock University, Ilishan Remo, Ogun State, Nigeria.
² Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa.
³ Institute of Bioanalytics and Agro-Metabolomics, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences Vienna (BOKU), Konrad Lorenz-Str. 20, A-3430 Tulln, Austria.
⁴ Microbiology and Environmental Biotechnology Research Group, Agricultural Research Council-Institute for Soil, Climate and Water, Pretoria, South Africa; Department of Biochemistry, Genetics and Microbiology, University of Pretoria, South Africa.
⁵ School of Food Science and Technology, Faculty of Science and Technology, Thammasat University (Rangsit Campus), Pathumthani, Thailand; Institute for Global Food Security, School of Biological Sciences, Queens University Belfast, Belfast BT9 5BN, Northern Ireland, United Kingdom.
⁶ Institute for Global Food Security, School of Biological Sciences, Queens University Belfast, Belfast BT9 5BN, Northern Ireland, United Kingdom.
⁷ Unit for Environmental Science and Management, North-West University (Potchefstroom Campus), Potchefstroom, South Africa.
⁸ Institute of Bioanalytics and Agro-Metabolomics, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences Vienna (BOKU), Konrad Lorenz-Str. 20, A-3430 Tulln, Austria; Institute for Global Food Security, School of Biological Sciences, Queens University Belfast, Belfast BT9 5BN, Northern Ireland, United Kingdom.
⁹ Department of Microbiology, Babcock University, Ilishan Remo, Ogun State, Nigeria; Institute of Bioanalytics and Agro-Metabolomics, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences Vienna (BOKU), Konrad Lorenz-Str. 20, A-3430 Tulln, Austria. Electronic address: chaugez@gmail.com.

PMID: 33992353
DOI: 10.1016/j.foodres.2021.110241

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.

Keywords: Bacterial diversity; Beverage; Cereals; Millet; Mycotoxins; Ogi.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bacteria / genetics
Beverages
Edible Grain / chemistry
Millets
Mycotoxins* / analysis
RNA, Ribosomal, 16S

Substances

Mycotoxins
RNA, Ribosomal, 16S