Isolation, screening and characterization of lysine-producing bacteria isolated from different rhizosphere in Rivers State

The aim of this study was to isolate, screen, and characterize lysine-producing bacteria from various rhizospheres. Nine samples of soil from various rhizospheres were collected from farmlands that grow cassava, yam, and plantains. Analysis of the samples were carried out and the isolates were identified using biochemical, microbiological standards and molecular techniques. The bacterial isolates were screened for lysine secretion using solid agar medium and the agar plates were observed for halo, an indication of lysine secretion by the isolate. The following bacteria were isolated from different samples: Klebsiella sp., Corynebacterium sp., Pseudomonas sp., Staphylococcus sp., Bacillus sp., Morganella sp., Acinetobacter sp., Micrococcus sp., Aerococcus sp., Tatumella sp. and Providencia sp. The result revealed that out of the eleven isolates, only five isolates had potential for lysine secretion with isolates UCS2 and RPS1 displaying the highest halo zone of 4.0 mm and selected as the best lysine producers. The selected isolates were molecularly identified as Corynebacterium jeikeium and Corynebacterium glutamicum. This study revealed that soil harbours bacteria which possess great potential for lysine production and should be exploited for biotechnology advancement.