Isolation and identification of phytase-producing <i>Bacillus</i> and <i>Enterobacter</i> species from Nigerian soils

Abstract

The bioavailability of phosphorus and other nutrients in feed for monogastrics is restricted by the presence of phytate. Exogenous supply of phytase produced by bacteria and other microbes can enhance the bioavailability of these nutrients and reduce phosphorus pollution. The objective of the study was to isolate bacteria with phytase-producing potentials from soil; which may be employed for the bioavailability of phosphorus and other nutrients in feed for monogastrics in Nigeria. Top soil samples were collected from two dumpsites in Lagos, Nigeria and bacteria were isolated and screened for potentials to produce phytase. The isolates with phytase potential were primarily identified by their cultural and biochemical  characteristics and then confirmed using the 16S rRNA sequencing, after which their expressed phytases were quantified. A total of six isolates  belonging to three species were identified as phytase producers. Sequence data analyses revealed these to be Bacillus subtilis (2), Bacillus  amyloliquefaciens (3) and Enterobacter cloacae (1) with accession numbers MH879827 and MH879832; MH879828, MH879830 and MH879831; and MH879829 respectively. Phenotypic phytase activity was highest in E. cloacae ODS 29 (9.69 ± 0.04 U/ml) and least in B. subtilis ODS 10 (8.83 ± 0.02 U/ml). In conclusion, phytase-producing Bacillus and Enterobacter species were isolated and characterized from Nigerian soils. These bacteria species could be used in biotechnological applications.

Keywords: Bacillus, Enterobacter, Monogastrics, Phylogenetic analysis, Phytase