Polynucleotide phosphorylase is involved in the control of lipopeptide fengycin production in Bacillus subtilis

Abstract

Bacillus subtilis is a wealth source of lipopeptide molecules such as iturins, surfactins and fengycins or plipastatins endowed with a range of biological activities. These molecules, designated secondary metabolites, are synthesized via non-ribosomal peptides synthesis (NRPS) machinery and are most often subjected to a complex regulation with involvement of several regulatory factors. To gain novel insights on mechanism regulating fengycin production, we investigated the effect of the fascinating polynucleotide phosphorylase (PNPase), as well as the effect of lipopeptide surfactin. Compared to the wild type, the production of fengycin in the mutant strains B. subtilis BBG235 and BBG236 altered for PNPase has not only decreased to about 70 and 40%, respectively, but also hampered its antifungal activity towards the plant pathogen Botrytis cinerea. On the other hand, mutant strains BBG231 (srfAA) and BBG232 (srfAC) displayed different levels of fengycin production. BBG231 had registered an important decrease in fengycin production, comparable to that observed for BBG235 or BBG236. This study permitted to establish that the products of pnpA gene (PNPase), and srfAA (surfactin synthetase) are involved in fengycin production.

Construction and description of a constitutive plipastatin mono-producing Bacillus subtilis

“…Another aim of this study was to construct a strain that ensures constitutive plipastatin mono-production. In a recent work, it was shown that deletion of srfAA signi cantly reduces the plipastatin production and on the other hand deletion of srfAC showed no effect [23]. The authors argued that probably srfAA and comS have a regulatory effect on fengycin production.…”

“…encode for more than one lipopeptide synthetase, which are not synthesized simultaneously in the same growth phase showing the involvement of different regulators. More speci cally, in the genome of bacteria that have the ppsABCDE operon, the srfAA-AD operon is always present as well [22,23]. However, while surfactin is being produced in the late exponential phase, the biosynthesis of plipastatin has been characterized in the stationary phase [23][24][25].…”

“…More speci cally, in the genome of bacteria that have the ppsABCDE operon, the srfAA-AD operon is always present as well [22,23]. However, while surfactin is being produced in the late exponential phase, the biosynthesis of plipastatin has been characterized in the stationary phase [23][24][25]. Lipopeptide synthetases are usually regulated by complex regulatory networks in a growth-phase dependent manner.…”

Construction and description of a constitutive plipastatin mono-producing Bacillus subtilis

“…encode for more than one lipopeptide synthetase, which are not synthesized simultaneously in the same growth phase showing the involvement of different regulators. More speci cally, in the genome of bacteria that have the ppsABCDE operon, the srfAA-AD operon is always present as well [24,25]. However, while surfactin is being produced in the late exponential phase, the biosynthesis of plipastatin has been characterized in the stationary phase [25][26][27].…”

“…More speci cally, in the genome of bacteria that have the ppsABCDE operon, the srfAA-AD operon is always present as well [24,25]. However, while surfactin is being produced in the late exponential phase, the biosynthesis of plipastatin has been characterized in the stationary phase [25][26][27]. Lipopeptide synthetases are usually regulated by complex regulatory networks in a growth-phase dependent manner.…”