Synergy of Actinomycete Co-inoculation

Abstract

Historically the symbioses between leguminous plants and rhizobia haveattracted the attention of researchers due to the incidence of legumes forsustaining nutritional requirements to humans and animals. There have beenlarge efforts to increase the ability to symbioticN2 fixing and productivity oflegumes. New research is focusing on increasing the legume?rhizobiasymbiosis with increased biological nitrogen fixation (BNF), growth, andproductivity. The inoculation of legumes with rhizosphere bacteria has oftenbeen found to increase symbiotic properties, plant biomass, and yields undergreenhouse or field conditions. The potential to enhance plant growth,nodulation, nitrogen fixation, productivity of legumes by plant growthpromotingrhizobacteria (PGPR), and Rhizobium co-inoculation does exist,although most of studies have been conducted with Bacillus spp., Pseudomonasspp., or other genera and few with actinomycetes. The latter, a groupof actinobacteria widely distributed in terrestrial ecosystems contribute tosoil nutrient cycling and live in association with plants and are considered asone of the most important communities in the rhizosphere. They have a greatability to synthesize a series of bioactivemetabolites and potential within theagroecosystem, where they play important roles in disease suppression andplant growth promotion in cultivated plants. In this sense, the purpose of thischapter is to show the synergistic effect of actinomycete co-inoculation onN2-fixing symbioses and their potential use in agriculture.