Molecular Study of the Phytase Gene in Lactic Acid Bacteria Isolated from Ogi and Kunun-Zaki, African Fermented Cereal Gruel and Beverage

Background and objective: Phytate is an anti-nutritional agent in cereal foods, making nutritional and health problems in human. The gene responsible for the degradation of phytate has been identified in many bacterial species but not in lactic acid bacteria. The objective of this study was to isolate and characterize phy gene in lactic acid bacteria isolated from Ogi and Kunun-zaki. Materials and methods: Lactic acid bacteria from Ogi and Kunun-zaki were phenotypically screened for phytase production. The phytate-degrading lactic acid bacteria isolates were identified using 16S rRNA gene sequencing. Amplification of phytase (phy) gene was carried out using polymerase chain reaction. Furthermore, phylogenetic analyses were carried out. Soluble proteins of three selected isolates were extracted and analyzed using sodium dodecyl sulphate polyacrylamide agarose gel electrophoresis. Results and conclusion: Totally, 16 isolates of phytate-degrading lactic acid bacteria were identified as Lactobacillus brevis, Lactobacillus plantarum subsp. plantarum, Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus paraplantarum. The phy gene with an amplicon size of 2.0 kb was amplified and sequenced. Sequence similarities between the phy genes of lactic acid bacteria and that of Bacillus in GenBank included 97-99% with a phylogenetic relationship of less than 40%. The SDS-PAGE electrophoresis analysis revealed a 50-kDa molecular weight of the phytase in the three isolates. This study has shown that phy gene of the lactic acid bacteria presents in fermented foods, suggesting its potential product use as starter to produce fermented foods with improved nutritional qualities.