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 agrobiotechnology. Lipopeptides produced by such organisms play a major role in their potential to inactivate pathogens. 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 variability. 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 possibly are glycosylated. These compounds may be of interest therapeutically, because polymyxins have gained 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 compounds (VOCs) was strain and medium dependent. In particular, strain M1 manifested as an efficient VOC-producer that exhibited formation of 25 volatiles in total. A characteristic feature of Paenibacilli is the formation of volatile pyrazine derivatives.

Beyond Soil-Dwelling Actinobacteria: Fantastic Antibiotics and Where to Find Them

“…Discovered in the 1940s, they fell in disuse due to their toxicity, but the current antimicrobial resistance crisis and the lack of alternatives have quickly brought them back to relevance [ 165 ]. In addition to polymyxins, P. polymyxa strains also produce fusaricidins, hexadepsipeptides with a lipid side-chain active against Gram-positive bacteria, pathogenic fungi such as Fusarium or even the closely related P. larvae , as well as (L)-(−)-3-phenyllactic acid ( Figure 6 ), another antifungal molecule [ 166 , 167 , 168 ]. A recent comparative genomic analysis of over 40 P. polymyxa strains has revealed this species is biosynthetically gifted, with its pangenome containing hundreds of potential BGCs, many of those with no known products [ 169 ].…”

Volatile organic compounds produced by Paenibacillus polymyxaJ2‐4 exhibit toxic activity against Meloidogyne incognita

“…15 Moreover, P. polymyxa strains LMG27872, GBR-1, and GBR-462 have demonstrated potential for controlling RKNs by inhibition of M. incognita egg hatching and reducing the number of females in host plants. [16][17][18] The antagonistic mechanisms employed by P. polymyxa involve the production of volatile organic compounds (VOCs), hydrolytic enzymes, and antifungal metabolites against plant pathogens, [19][20][21][22][23][24][25] among which VOCs have a crucial role in the defense process. For instance, VOCs, such as benzothiazole and benzaldehyde isolated from P. polymyxa WR-2, effectively inhibited the growth of Fusarium oxysporum.…”

Active Metabolites From the Endophyte Paenibacillus polymyxa Y-1 of Dendrobium nobile for the Control of Rice Bacterial Diseases

“…Dendrobium nobile ( D. nobile ), a medicinal and edible plant, is native to China and belongs to the Orchidaceae family, which is rich in endophytic bacteria ( Cai et al, 2015 ). Among them, Paenibacillus polymyxa ( P. polymyxa ) is an important endophytic bacterium from D. nobile , which can produce a variety of active metabolites, such as polymyxins ( Niu et al, 2013 ; Mülner et al, 2021 ), paenibacillin ( Huang and Yousef, 2015 ; Campbell et al, 2021 ), fusaricidins ( Mikkola et al, 2017 ; Mülner et al, 2021 ), cytokinins ( Liu et al, 2020 ), auxins ( Sadhana and Tabacchioni, 2009 ), chitinase ( Belén et al, 2020 ), and hydrolase( Sadhana and Tabacchioni, 2009 ). These metabolites can promote plant growth, improve plant nutrient utilization, and induce plant systemic resistance.…”