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=6

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=<p><italic>Paenibacillus polymyxa</italic> is a common soil bacterium with broad range of practical applications. An important group of secondary metabolites in <italic>P. polymyxa</italic> are non-ribosomal peptide and polyketide derived metabolites (NRPs/PKs). Modular non-ribosomal peptide synthetases catalyze main steps in the biosynthesis of the complex secondary metabolites. Here we report on the inactivation of an A26 Sfp-type 4'-phosphopantetheinyl transferase (Sfp-type PPTase). The inactivation of the gene resulted in loss of NRPs/PKs production. In contrast to the former <italic>Bacillus</italic> spp. model the mutant strain compared to wild type showed greatly enhanced biofilm formation ability. A26Δ<italic>sfp</italic> biofilm promotion is directly mediated by NRPs/PKs, 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. Challenges with <italic>P. polymyxa</italic> genetic manipulation are discussed.</p>