AUTHOR=Timmusk Salme , Kim Seong-Bin , Nevo Eviatar , Abd El Daim Islam , Ek Bo , Bergquist Jonas , Behers Lawrence 

TITLE=Sfp-type PPTase inactivation promotes bacterial biofilm formation and ability to enhance wheat drought tolerance

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 6 - 2015

YEAR=2015

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.00387

DOI=10.3389/fmicb.2015.00387

ISSN=1664-302X

ABSTRACT=Paenibacillus polymyxa is a common soil bacterium with broad range of practical applications. An important group of secondary metabolites in P. polymyxa are nonribosomal peptide and polyketide derived metabolites (NRP/PK). Modular nonribosomal peptide synthetases catalyse main steps in the biosynthesis of the complex secondary metabolites. Here we report on the inactivation of an A26 sfp-type phosphopantetheinyl transferase. The inactivation of the gene resulted in loss of NRP/PK production. In contrast to the former Bacillus spp. model the mutant strain compared to wild type showed greatly enhanced biofilm formation ability. Its biofilm promotion is directly mediated by NRP/PK, as exogenous addition of the wild type metabolite extracts restores its biofilm formation level.  Wheat inoculation with bacteria that had lost their sfp-type PPTase gene resulted in two times higher plant survival and about three times increased biomass under severe drought stress compared to wild type.