Comparative genomics of a consortium of plant growth promoting bacteria

Abstract

Three Bacillus strains (Bacillus licheniformis, Bacillus thuringiensis_Lr 3/2 and Bacillus thuringiensis Lr7/2) were isolated from various soil samples. Both Bacillus thuringiensis_Lr 3/2 and Bacillus thurin- giensis_Lr7/2 were obtained from the Atacama Desert, Chile, during a sampling campaign in 2011 by Professor Pilar Junier (laboratory of microbiology - University of Neuchâtel). Whereas B. licheniformis was isolated from Agroscope Liebefeld, Bern, Switzerland. These Bacillus strains are known to work together in a mutualistic consortium and influence plant growth, they have also been shown to enhance the total dry weight of the plant and increase the quality of the seeds in oat species. This study used a comparative genomics approach at the molecular level of the three Bacillus strains, in order to improve knowledge and understanding of how this consortium benefits by existing together. The three genome sequences of the Bacillus strains are similar to each other to some extent. Therefore, large numbers of genes involved with plant growth promoting bacteria have been identified, for example, IAA synthe- ses and nitrogen fixation. As well as this, genes associated with chemotaxis and motility have also been identified in these strains.