Gluconacetobacter azotocaptans: A Plant Growth-Promoting Bacteria

Abstract

Gluconacetobacter diazotrophicus is a very well-known and well-studied mem ber of family Acetobacteraceae. Strains of this species have been isolated from all over the world. On the other side, only two strains of Gluconacetobacter azotocaptans have been isolated, i.e., one from coffee plant in Mexico (type strain) and another from corn plant in Canada; therefore, not much information is available about it. This chapter is an effort to bring this species in the limelight and show its significance as plant growth promoter. Authors have not only iso lated the strain DS1, they have also evaluated its plant growth-promoting poten tial in four varieties of corn, radish, cucumber, tomato, pepper, and potato, under greenhouse, field, and tissue culture conditions, and data is presented in this chapter. Inoculation effect of DS1 was compared with G. diazotrophicus PAL5, its nif mutant, and strains of other genera including Pseudomonas, Azospirillum, Enterobacter, Burkholderia, and Sphingobacterium. Work on wheat was done by another group in Canada, and their data has also been added. It is a nitrogen fixing, indole acetic acid-producing strain with phosphate solubilization ability. It has promoted the plant growth in most cases. Its growth-promoting effect var ied in tissue culture medium depending on sucrose concentration as it is linked with IAA and ethylene production. Based on data presented here, authors are recommending its use as a biofertilizer.