Production of rhizobia biofertilizers using baker's yeast effluent and their application toLeucaena leucocephala

Abstract

Industrial baker's yeast effluent (BYE) was experimented on as a culture medium for growth and biomass production of six fast-growing rhizobia strains. Diluting the effluent with distilled water was necessary to maximize bacterial biomass production. The addition of phosphate buffer, ammonium chloride or trace-elements did not improve the final biomass yield of tested micro-organisms. Rhizobial growth and biomass on the effluent were comparable to traditional yeast extract mannitol medium (YEM). The Rhizobium spp. biomass, produced using either YEM or BYE, was evaluated as inoculum for Leucaena leucocephala (Lam.) de Wit in a pot experiment. No significant differences were reported in respect of legume nodule and growth parameters. Simultaneous inoculation with rhizobia and a group of associative diazotrophs supported better nodulation and nitrogenase activity.