Phenotypic and biochemical characterization with confirmatory testing of isolates from Lablab purpureus

Known for its adaptability, Lablab purpureus is grown for many reasons and greatly increases world grain legume consumption. Being one of the most flexible legumes, this plant is rather agronomically relevant. Using soil samples gathered from the Rajgarh area of Madhya Pradesh, the present work focuses on the isolation and characterisation of L. purpureus isolates depending on their morphological and biochemical characteristics. After 3 to 5 days of incubation on YEMA plates, the isolates produced white, mucilaginous colonies with diameters from 1 to 3 mm, approximating reference strains in roundness and elevation. Of the 32 isolates studied, 27 were gram-negative and 5 were gram-positive. While three were classified as coccus-shaped, most isolates showed rod-shaped morphology. Most of the white colonies came from those cultivated on YEMA-Congo red plates; 6 isolates, however, dyed red. The ketolactose test also indicated four isolates could generate the ketolactose enzyme.