Monitoring the effect of fortification on bacterial

Wakil and Onilude. .………………………..J. Appl. Biosci. 2010. Monitoring effect of fortification on bacterial populations

Journal of Applied Biosciences 26: 1604 - 1613
ISSN 1997–5902Monitoring the effect of fortification on bacterial population dynamics in malted and fermented maizebased weaning foods using PCR-DGGE
Wakil, Sherifah Monilola* and Onilude, Abiodun AnthonyDepartment of Botany and Microbiology, University of Ibadan, Ibadan, Nigeria. *Corresponding author email:Shemowak@yahoo.com; Tel: (+234)8034129496
Original submitted on 23rd November 2009.Published online at www.biosciences.elewa.org on February 8, 2010.

ABSTRACT Objective: To evaluate the effect of fortification on the microbial population dynamics of naturally fermenting maize–legume weaning blends. Methodology and results: Maize fortified with cowpea, and cowpea-groundnut blends were formulated and spontaneously fermented for 72h. Enumeration using culture-dependent method revealed that microbial cell counts increased drastically within the first 24h in maize-cowpea blends while it took longer (within the first 48h) in maize-cowpea-groundnut blends.The analysis of the Denaturing Gradient Gel Electrophoresis (DGGE) pattern of the fermented blends obtained with bacterial primers targeting the 16S rDNA genes clearly demonstrated thatthere was a major shift in the community structure within the first 24h. The species richness (R) for the total bacterial community varied from a low value (9) for maize-cowpea blends to a 15 formaize-cowpea -groundnut blends. The biodiversity index (H’) as well as concentration of dominance (S) according to Shannon and Weaver and Simpson’s index, respectively, varied significantlywith the supplementation type with the maize-cowpea -groundnut sample maintaining high biodiversity throughout the fermentation period. Statistical analysis showed a significant difference (P