A novel six-phage cocktail reducesPectobacterium atrosepticumsoft rot infection in potato tubers under simulated storage conditions

Abstract

Pectobacterium atrosepticum is a species of plant pathogenic bacteria responsible for significant losses in potato production worldwide. Pectobacterium atrosepticum can cause blackleg disease on potato stems as well as the tuber disease termed potato soft rot. Methods for the effective control of these diseases are limited and are primarily based on good agricultural practices. Bacteriophages, viruses of bacteria, could be used as an alternative, environmentally friendly, control measure. Here, we describe the isolation and characterization of 29 phages virulent to P. atrosepticum. The phages belong to 12 different species based on a 95% sequence identity cut-off. Furthermore, based on sequence diversity and propagation results, we selected six of these phages to form a phage cocktail. The phages in the cocktail was tested on a number of P. atrosepticum strains in order to determine their host range. The phages was found to lyse 93% of the tested strains. The cocktail was subsequently tested for its effectiveness in combatting potato soft rot under simulated storage conditions. Use of the phage cocktail reduced both disease incidence and disease severity by 61% and 64%, respectively, strongly indicating that phage biocontrol has the potential to reduce the economic impact of soft rot in potato production.

Morphologically Different Pectobacterium brasiliense Bacteriophages PP99 and PP101: Deacetylation of O-Polysaccharide by the Tail Spike Protein of Phage PP99 Accompanies the Infection

“…One of the pathogen groups that were studied in this context are pectolytic bacteria Pectobacterium and Dickeya, where good results of phage application have been reported. Most trials in phage control were applied either to the most widespread or most virulent pathogens-P. carotovorum (Lim et al, 2013;Muturi et al, 2019), P. atrosepticum (Carstens et al, 2019) and Dickeya solani (Adriaenssens et al, 2012;Czajkowski et al, 2017). Most phages suitable for the control of these phytopathogens are members of subfamilies Autographivirinae, Aglimvirinae, and lytic phages belonging to the less characterized genera.…”

Isolation and complete genome sequencing of Pectobacterium phage Jarilo, representing a novel genus of bacteriophages within the subfamilyAutographivirinae

“…Jarilo was isolated from an organic waste sample as described previously [12], using Pectobacterium carotovorum DSM 30170 as host. Prior to isolation virus particles in the organic waste sample was concentrated by polyethylene glycol precipitation, as described elsewhere [13].…”

“…Due to limited control mechanism, increased attention have been directed towards biological control agents [6]. Phages have been proposed as promising biocontrol agents towards Pectobacteriaceae in several studies [7][8][9][10][11][12]. In this report, we describe the isolation and characterization of Pectobacterium phage Jarilo, representing a new genus of bacteriophages within the subfamily Autographivirinae.…”

Genomic characterization of three novelPseudomonasphages within the subfamily ofAutographivirinaeisolated from organic waste

“…Samples of organic waste (OW) was collected, aliquoted and filtered with 0.45 μm syrin m syringe filters. The filtrate were tested for phage activity against P. syringae GAW0113 using a double agar overlay assay [7]. Plaques with distinct appearance or size were purified thrice.…”

“…Plaques with distinct appearance or size were purified thrice. The phage DNA was extracted from lysate, as previously described [7] Phage DNA libraries were prepared using NEBNext Ultra II FS The position of the terminal repeats were identified by the presence of two distinct spikes in read-start coverage at two nearby sites in the genome, encompassing areas with approximately double readcoverage. Open reading frames (ORFs) were identified automatically with GeneMark [9] and Glimmer [10] and revised manually in DNA Master [11].…”