AUTHOR=Okeke Chiamaka A. , Ezekiel Chibundu N. , Nwangburuka Cyril C. , Sulyok Michael , Ezeamagu Cajethan O. , Adeleke Rasheed A. , Dike Stanley K. , Krska Rudolf 

TITLE=Bacterial Diversity and Mycotoxin Reduction During Maize Fermentation (Steeping) for Ogi Production

JOURNAL=Frontiers in Microbiology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.01402

DOI=10.3389/fmicb.2015.01402

ISSN=1664-302X

ABSTRACT=<p>Bacterial diversity and community structure of two maize varieties (white and yellow) during fermentation/steeping for <italic>ogi</italic> production, and the influence of spontaneous fermentation on mycotoxin reduction in the gruel were studied. A total of 142 bacterial isolates obtained at 24–96 h intervals were preliminarily identified by conventional microbiological methods while 60 selected isolates were clustered into 39 OTUs consisting of 15 species, 10 genera, and 3 phyla by 16S rRNA sequence analysis. Lactic acid bacteria constituted about 63% of all isolated bacteria and the genus <italic>Pediococcus</italic> dominated (white maize = 84.8%; yellow maize = 74.4%). <italic>Pediococcus acidilactici</italic> and <italic>Lactobacillus paraplantarum</italic> were found at all steeping intervals of white and yellow maize, respectively, while <italic>P. claussenii</italic> was present only at the climax stage of steeping white maize. In both maize varieties, <italic>P. pentosaceus</italic> was found at 24–72 h. Mycotoxin concentrations (μg/kg) in the unsteeped grains were: white maize (aflatoxin B<sub>1</sub> = 0.60; citrinin = 85.8; cyclopiazonic acid = 23.5; fumonisins (B<sub>1</sub>/B<sub>2</sub>/B<sub>3</sub>) = 68.4–483; zearalenone = 3.3) and yellow maize (aflatoxins (B<sub>1</sub>/B<sub>2</sub>/M<sub>1</sub>) = 22.7–513; citrinin = 16,800; cyclopiazonic acid = 247; fumonisins (B<sub>1</sub>/B<sub>2</sub>/B<sub>3</sub>) = 252–1,586; zearalenone = 205). Mycotoxins in both maize varieties were significantly (<italic>p</italic> &lt; 0.05) reduced across steeping periods. This study reports for the first time: (a) the association of <italic>L. paraplantarum</italic>, <italic>P. acidilactici</italic>, and <italic>P. claussenii</italic> with <italic>ogi</italic> production from maize, (b) citrinin occurrence in Nigerian maize and <italic>ogi</italic>, and (c) aflatoxin M<sub>1</sub>, citrinin and cyclopiazonic acid degradation/loss due to fermentation in traditional cereal-based fermented food.</p>