Fusaricidins, Polymyxins and Volatiles Produced by Paenibacillus polymyxa Strains DSM 32871 and M1

Abstract

Paenibacilli are efficient producers of potent agents against bacterial and fungal pathogens, which are of great interest both for therapeutic applications in medicine as well as in agrobiotechnol-ogy. Lipopeptides produced by such organisms play a major role in their inactivation potential. In this work we investigated two lipopeptide complexes, the fusaricidins and the polymyxins, produced by Paenibacillus polymyxa strains DSM 32871 and M1 by MALDI-TOF mass spectrometry. The fusaricidins show potent antifungal activities and are distinguished by an unusual variabil-ity. For strain DSM 32871 we identified numerous yet unknown variants mass spectrometrically. DSM 32871 produces polymyxins of type E (colistins), while M1 forms polymyxins P. For both strains novel, but not yet completely characterized polymyxin species were detected, which pos-sibly are glycosylated. These compounds may be of interest therapeutically, because polymyxins attain increasing attention as last-resort antibiotics against multiresistant pathogenic Gram-negative bacteria. In addition, the volatilomes of DSM 32781 and M1 were investigated with a GC-MS approach using different cultivation media. Production of volatile organic com-pounds (VOCs) was strain and medium dependent. In particular, strain M1 manifested as an effi-cient VOC-producer that exhibited formation of 25 volatiles in total. A characteristic feature of Paenibacilli is the formation of volatile pyrazine derivatives.

Endophytic Paenibacillus polymyxa LMG27872 inhibits Meloidogyne incognita parasitism, promoting tomato growth through a dose-dependent effect

“…Paenibacillus polymyxa has been described as a successful biocontrol organism against various plant pathogens, including bacteria, fungi, oomycetes, and PPNs (Khan et al, 2008;Son et al, 2009;Cheng et al, 2017;Chávez-Ramírez et al, 2020. It is known to produce antibiotic compounds and secondary metabolites, such as non-ribosomally synthesized lipopeptides, polymyxins, fusaricidin, sideromycins, macrolactin D, and other VOCs, with direct effects on pathogens or inducing resistance through elicitation of plant systemic defense (Raza et al, 2009;Zhao et al, 2011;Lee et al, 2012;Raza et al, 2015;Lal et al, 2016;Cheng et al, 2017;Krämer et al, 2020;Langendries and Goormachtig, 2021;Mülner et al, 2021). Paenibacillus polymyxa is known to secrete siderophores, a known secondary metabolite that scavenges iron, protecting the plants from oxidative stress (Raza et al, 2011;Zhou et al, 2016;Kramer et al, 2020).…”