Enhancing titre and production stability of paenibacillin from Paenibacillus polymyxa by sequential drug resistance screening

Abstract

Aims Paenibacillin is a naturally biosynthesized antimicrobial lantibiotic peptide which is produced by wild‐type Paenibacillus polymyxa OSY‐DF in low but detectable levels. The aim was to increase paenibacillin titre and production consistency through sequential drug resistance screening. Methods and results Spontaneous mutants of P. polymyxa OSY‐DF were isolated by subjecting the bacterium to two rounds of screening for resistance to rifampicin, which targets RNA polymerase, and gentamicin, which targets ribosomes. Changes in antimicrobial production of the mutants were monitored using a bioassay method. A spontaneous mutant, P. polymyxa OSY‐EC, capable of producing high paenibacillin titre, was selected and compared phenotypically to the wild‐type strain. The mutant was found to produce paenibacillin at five‐fold higher titre than the wild type. The mutant constantly produced paenibacillin while the wild type produced the antimicrobial agent variably. Fourier transformation mid‐infrared spectroscopy revealed an interclass distance of 6·4 between the wild type and the mutant strain, suggesting significant phenotypic change during the mutation. Conclusions P. polymyxa OSY‐EC, a spontaneous mutant capable of consistent production of high paenibacillin titre, was isolated from the wild type after sequential screening on rationally selected antibiotics. Significance and Impact of the Study The study will help make paenibacillin available for large‐scale testing by interested researchers and industries seeking applications that improve food safety and quality.

Maximizing Recovery of Paenibacillin, a Bacterially Produced Lantibiotic, Using Continuous Foam Separation from Bioreactors

“…A sufficient bioreaction time is needed for production threshold of paenibacillin, accumulation of the antimicrobial agent in sufficient amounts, and its migration to the air–water interface. Excessively long incubation time may cause the degradation of accumulated paenibacillin in bioreaction medium [ 6 ]. Stir speed and airflow influence foam formation and stability, and therefore affect the ability of foam to form and reach the collection flask [ 22 ].…”

“…The newly developed efficient paenibacillin-producing strain, Paenibacillus polymyxa OSY-EC [ 6 ], was used in this study. Listeria innocua ATCC 33090 was used as a sensitive bioassay indicator to determine paenibacillin concentration; this strain has been used previously for measuring anti-Gram-positive activity of paenibacillin-producing culture [ 1 ].…”

“…The broad antimicrobial coverage and desirable physico-chemical characteristics make paenibacillin a promising antimicrobial candidate for the preservation of food, cosmetics, and other perishable products. The wild producer strain, P. polymyxa OSY-DF [ 4 ], has been improved and an alternate strain, P. polymyxa OSY-EC, that produces paenibacillin on a consistent basis was developed recently [ 6 ]. The new strain resulted from screening for wild strain’s spontaneous mutants that are resistant to antibiotics known to target protein synthesis mechanisms.…”

“…The new strain resulted from screening for wild strain’s spontaneous mutants that are resistant to antibiotics known to target protein synthesis mechanisms. Despite the enhancement achieved through strain selection [ 6 ], there is a need for improving the recovery of paenibacillin produced in industrially relevant bioreactions.…”

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.…”