Paenibacillus, Nitrogen Fixation and Soil Fertility

Abstract

Plant growth-promoting rhizobacteria (PGPR) can influence the growth and health of plants directly, by the suppression of deleterious microorganisms through antagonistic functions, by inducing plant resistance to diseases, by furnishing nutrients, by the production of plant growth-regulating substances, and/or by fixing atmospheric nitrogen. Within the genus Paenibacillus, 16 species are considered to harbour nitrogen-fixing strains: P. polymyxa, P. macerans, P. peoriae, P. durus, P. brasilensis, P. graminis, P. odorifer, P. borealis, P. wynnii, P. massiliensis, P. sabinae, P. donghaensis, P. zanthoxyli, P. forsythiae, P. riograndensis and P. sonchi. Besides the capability to fix nitrogen, many strains belonging to these species present other characteristics important for plant health and growth promotion. The contributions of these species as PGPR and/or to soil fertility are discussed in this chapter. Moreover, methods that provide a rapid tool for the characterization and the establishment of the taxonomic position of isolates belonging to the nitrogen-fixing group are presented.